SESES IS Insnstrutrumentsnts Pv Pvt. Lt. Ltd.td.3.imimg.com/data3/KE/MK/MY-526573/ses-catalogue.pdf · Magnetic Hysteresis Loop Tracer: HLT-111 34 36. Study of P-N Junctions (Bandgap

SES Instruments Pvt. Ltd.SES Instruments Pvt. Ltd.

24. Four Probe Set-up: DFP-RM (Research Model) 21

25. Four Probe Set-up (Resistivity Mapping): FP-01 23

26. Measurement of Magnetoresistance: MRX-01 23

27. Two Probe Method for Resistivity Measurement TPX-01 25

28. Electron Spin Resonance Spectrometer: ESR-104 26

29. Study of Thermoluminescence of F-centres TLX-02 27

30. Hall Effect Experiment: HEX-21 28

31. Hall Effect in Metals: HEM-01 29

32. Dependence of Hall Coefficienton Temperature: HEX-22 31

33. Quinck's Tube Method (QTX-01) 32

34. Gouy's Method: GMX-01 33

35. Magnetic Hysteresis Loop Tracer: HLT-111 34

36. Study of P-N Junctions(Bandgap & Diffusion Potential): PN-1 35

37. Semiconductors Diodes Characteristics(Advance Model): SDC-02 36

Physics and Electronics Experimental Setups

38. Study of a Transistor Amplifier (RC Coupled)Cum-Feed Back Amplifier: RC-01 37

39. Study of Multivibrators: MV-01 37

40. Study of Characteristics of SemiconductorsDiodes (Basic Model): D-1 38

41. Study of Hybrid Parametersof a Transistor: HP-01 38

42. Study of a Solid State Power Supply: SSPS-1 39

43. Study of Modulation & Demodulation withBuilt-in Carrier Frequency (Solid State): MD-1 39

44. Study of a Basic Operational Amplifier: 741-01 39

45. Study of Op. Amp. 74l Applications: 741-02 40

46. Study of Astable & Monostable Multivibrators using Timer IC: 555 40

47. Study of an Integrated Circuit Regulator: 723 40

Contents P a g e

General Laboratory Instruments

1. Digital D.C. Microvoltmeter: DMV-001 3

2. Digital Nanoammeter: DNM-121 3

3. Digital Picoammeter: DPM-111 4

4. High Voltage Power Supply: EHT-11 4

5. True RMS A.C. Millivoltmeter: ACM-102/ ACM-103 5

6. Electromagnet & Power Supply: EMU-75 & DPS-175 5

7. Electromagnet & Power Supply: EMU-50 & DPS-50 6

8. Digital Gaussmeter: DGM-102 6




12. PID Controlled Oven: PID-200 CT 8

13. Travelling Microscope: TVM-02 9

14. Travelling Microscope: TVM-03 9

15. Regulated Power Supply: PS-12 10

16. Function Generator: FG-01 10

Physics and Material Science Lab Experiments

17. Magnetic Field Measurement Apparatus: MFM-01 11

18. Study of Dielectric Constant: DEC-01 12

19. Planck's Constant Experiment(By Photoelectric Effect): PC-101 14

20. Study of Planck's Constant (Using LED's): PCA-01 16

21. Franck Hertz Experiment: FH-3001 18

22. Four Probe Experiment : DFP-02 (Basic Model) 19

23. Four Probe Experiment : DFP-03 (Advance Model) 20

Application : For the measurement of low currents down to 100pA

Current Range : 100nA to 100mA full scale in 4 decade ranges with 100%overranging (100pA minimum)

Accuracy : ±0.2% for all ranges

Display : 3½ digit, 7 segment LED with autopolarity and decimal indication

Input : Through BNC connector

Very low temperature drift

Low dc input bias current-10pA

Measures voltage down to 1mV

Recorder facility (optional)

Measures current downto 100pA

All solid state and IC design

Accepts either polarityof input current

DI AL N AMMEGIT ANO TERM e D - 121od l NM

I NT FI E I MESC E I C QU P NT

ROORKEE

I A M V EDIG T L ICRO OLTM TERMode DNM - 1l 00

SCIENT F C EQUIPMENTI IR ORKEEO

Digital Nanoammeter D N M - 1 2 12

Digital Microvoltmeter D M V - 0 0 11

Application : For very low d.c. voltage measurement at very high impedance

Range : 1mV, 10mV, 100mV, 1V & 10V with 100% over-ranging.

Resolution : 1mV

Accuracy : ±0.2%

Stability : Within ±1 digit

Input Impedance : >1000MW (10MW on 10V range)

Display : 3½ digit, 7 segment LED with autopolarity and decimal indication

3

Measures current down to 1pA

All solid state and IC design

Very low offset current

4

3 Digital Picoammeter

High Voltage Power Supply

D P M - 1 1 1

E H T - 1 1

Continuously variable

Electronically regulated

Fully solid state circuit

Low power consumption

Application

Current Range

Display

Accuracy

For the measurement of very low currents down to 1pA

1nA to 100mA full scale in 6 decade ranges with 100%over-ranging (1pA minimum)

3½ digit 7 segment LED display

±0.2% for all ranges

:

:

:

:

Application

Polarity

Range

Max. Current

Stability

Regulation

Display

Protection

EHT source for photomultiplier tubes and other radiation detectors

+ve or -ve, as required

0-200V & 0-1500V continuously adjustable

1mA

±0.05% for ±10% mains variation

±0.05% for 0 to 1mA load

3½ digit, 7 segment LED

Fully protected against overload and short circuit by currentlimiting technique

:

:

:

:

:

:

:

:

4

5 True RMS A.C. Millivoltmeter

Measures True RMS Voltage

Accuracy 1%

High Input Impedance

High Stablility

Excellent Linearity

A C M - 1 0 2 / 1 0 3

Application

Voltage Range

Freq. Range

Display

Input Impedance

Accuracy

ACM-103 (Additional Features)

Oscillator Output

Frequency

General purpose, indispensable to any electronics laboratory

20mV, 200mV, 2V and 20V

10Hz to 200KHz

3½ digit, 7 segment LED with autopolarity and decimal indication

1 Mohm shunted by 25pf on all ranges

1% (10Hz to 100KHz); 2% (100KHz to 200KHz)

:

:

:

:

:

:

0-300mV continuously variable

1KHz (sine) fixed

:

:

5

Constant Current Power Supply, DPS-175

Application : IC regulated constant current sourcessuitable for electromagnet EMU-75

Current : 0-3A per coil, smoothly adjustable

Line Regulation : ±0.1% for 10% mains variation

Load Regulation : ±0.1% for load variation from 0 to max.

Display : 3½ digit, 7 segment LED display

Protection : Protected against overload/short circuit.

6 Electromagnet & Power Supply E M U - 7 5 , D P S - 1 7 5

Electromagnet, EMU-75

Application : General purpose laboratory electromagnet

Pole Pieces : f75mm flat in EMU-75: f75mm tappered to 25mm in EMU-75T

Field : EMU-75: 10.75KG at 10mm airgap: EMU-75T: 17.5KG at 10mm airgap

Energising Coils :

Two, each having a resistance of approx. 13W

Power Requirement :

0-90Vdc, 3A, if coils are connected in series

0-45Vdc, 6A, if coils are connected in parallel

T F C I M NSCIEN I I EQU P E T

ORO RKEE

DIGITAL GAUSSMETERod M 1M el DG - 02

8

7 Electromagnet & Power Supply

Electromagnet,EMU-50

Application: Low costelectromagnet isspecially designed forHall Effect andMagnetic Susceptibilityby Quinck’s methodexperiments

Pole Pieces : f50mm diameter flat in EMU-50: f50mm tapered to 20 mm in EMU-50T

Field : EMU-50: 7.5KG, at 10mm airgap: EMU-50T: 9.5KG at 10mm airgap

Energising Coils: Two,each with a resistanceof about 3W

Power Requirement:0-30Vdc, 4A, if coilsare connected in series

Digital Gaussmeter

EM U-5 0 , DPS-50

D G M - 1 0 2

Mag. Field Measurement

Excellent Linearity

IC Controlled Circuit

Excellent Stability

Application

Range

Accuracy

Display

Transducer

Special Feature

Suitable for the measurement of magnetic field from 1gauss to 20KG

0-2KG, 0-20KG

±0.5%

3½ digit, 7 segment LED display

Hall Probe (InAs)

Indicate the direction of the magnetic field

:

:

:

:

:

:

6

Constant Current Power Supply, DPS-50

Application

Current

Line Regulation

Load Regulation

Display

Protection

IC regulated constant current sourcesspecially suitable for EMU-50

0-4A (smoothly adjustable)

±0.1% for ±10% mains changes

±0.1% for no to full load


Protected against overload/short circuit.

:

:

:

:

:

:

10

9 Digital Gaussmeter

Wide Range (1G to 20KG)

Excellent Linearity

Excellent Stability

Interchangeable Hall Probes

Digital Gaussmeter D G M - 1 0 3

D G M - 2 0 2

Range

Accuracy

Display

Transducer

Special Feature

0-2KG, 0-20KG

±0.5%

3½ digit, 7 segment LED display with auto polarity andoverflow indication

Hall Probe (InAs)

Indicates the direction of the magnetic field

:

:

:

:

:

Differential mode facility

Wide Range (1G to 40KG)

Excellent Linearity

Excellent Stability

Easy replacement of Hall Probe

Application

Range

Accuracy

Display

Transducer

Special Feature

Suitable for the measurement of magnetic field from 1 gaussto 40KG with differential mode facility

0-2KG, 0-20KG & 0-40KG

±0.5%


Hall Probe (InAs)

Indicates the direction of the magnetic field

:

:

:

:

:

:

7

Application :

Wide application in industry, where accurate measurements of magnetic field is required. Easy inter-changeability of probe enables both the axial and transverse field measurement with same unit

12

11 Digital Gaussmeter

Measures down to 0.1G

Excellent Linearity

Excellent Stability

Interchangeable Hall Probes

PID Controlled Oven

Introduction

This is high quality temperature controlled oven suitable for testing of electronic components & study of temperature transducers etc. The oven has been designed for fast heating and cooling rates which enhances the effectiveness of the controller. While the basic design of the controller is around the PID configuration for its obvious advantages, wastage of power is avoided by using a Pulse Width Modulated (PMW) switch. This combination has the advantages of both on-off controller and linear PID controller. The result is a good stable and accurate temperature control.

D G M - 2 0 4

P I D - 2 0 0 C T

Application : Suitable for magnetic field measurement from 0.1 gauss to 40KG. Easy interchangeability of probe enables both axial and transverse field measurement with same unit

Range

Accuracy

Resolution

Display

Transducer

Special Feature

0-200G, 0-2KG, 0-20KG and 0-40KG

±0.5%

0.1 gauss at 200G range

3½ digit, 7 segment LED with auto polarity and overflow

Hall Probe (InAs)

Indicate the direction of the magnetic field

:

:

:

:

:

:

Specifications of the Oven

Temperature Range

Stability

Measurement Accuracy

Oven Dimensions

Sensor

Display

Ambient to 200°C

Short Range: ±0.2°C Long Range: ±0.5°C

±0.5°C (typical)

Heating Chamber Inner Diameter: 25mm; Height: 100mm

RTD (A class)

3½ digit, 7 segment LED (12.5 mm)

:

:

:

:

:

:

8

14

13 Travelling Microscope

Travelling Microscope T V M - 0 3

T V M - 0 2

Introduction

The bed is of a heavy casting, thoroughly aged and machined, is fitted with leveling screws. On the dovetail guide ways slides the horizontal carriage which can be clamped at any position by means of a thumbscrew. A second sliding carriage slides along a gunmetal vertical pillar fitted on the horizontal carriage. The slow motion guide bars are made of sturdy material and the motion is very smooth.

(i) True achromatic objective with 7.5cm focussing distance from object

(ii) 10X Ramsden Eyepiece with fine cross wire

Horizontal scale

Vertical scale

Least Count

180mm with a screw gauge type motion

150mm with a screwgauge type motion

0.01mm on both scales

:

:

:

Scale

Optics

Introduction

The bed is of a heavy casting, thoroughly aged and machined, is fitted with leveling screws. On the dovetailed guide ways slide the carriage which can be clamped at any position by means of a thumbscrew. A sliding carriage slides along a gunmetal Vertical pillar fitted on the horizontal carriage. The slow motion guide bars are made of sturdy material and the motion is very smooth. Microscope tube is inclinable in any angle. True vertical and horizontal positions marked focussing. Scales and verniers are made of lifetime Stainless Steel.

9

Optics

True achromatic objective with 7.5cm focussing distance from object; 10XRamsden Eyepiece with fine cross wire is provided.

Horizontal scale

Vertical scale

Lateral Scale

Least Count

180mm with a screw gauge type motion

150mm with a vernier scale

60mm with a vernier scale

0.01mm on all scales

:

:

:

:

Scale

16

15 Regulated Power Supply

Application: General purposelow cost power source ideallysuited for analog and digital IC’s

Output: Four fixed voltages viz.+5V, -5V, +12V, and -12V

Current: 300mA max for each

Regulation: ±0.2% for noload to full load

Protection: Internally protected byover-current and thermal shutdown

Function Generator

4-digit counter basedfrequency display –Maximum error ONE LSB

Square, sine and triangularoutput upto 2MHz

IC based circuit – highstability, low distortion

PS-12

FG-01

This is an economical priced signal source. The IC used is a high frequency functiongenerator that produce low distortion sine, square and triangular waveform from lessthan 1Hz to 20MHz

Applications

Waveforms

Frequency

Amplitude

Output Impedance

Frequency Readout

General purpose instrument, indespensable to anylaboratory

Square/ Sine/ Triangular (switch selectable)

10Hz – 2MHz in six ranges

0-3V (p-p)

50W

4-digit counter

:

:

:

:

:

:

10

SCIENTIFI EQUIPMENTC

ROORKEE

I L C REGU ATED POWER SUPPLY

Model PS 12

F MUNCTION GENERATOR odel : FG-01

SCIENT FIC EQUIPMENTI

ROORKEE

Magnetic Field Measurement Apparatus M F M - 0 117

11

The experiment consists of two coils, Constant Current Power Supply and Gaussmeter. The Gaussmeter probe is mounted on a rail with a scale. It can move smoothly and precisely for measurement of magnetic field along the axis of the coils.

The following studies can be carried out with the set-up:

1. Study of magnetic field due to one coil and calculation of its diameter.

2. Study of Principal of super-imposition of magnetic field due to 2 coils by keeping the distance between the coils at a, >a and <a, where a is the radius of the coil.

Legend:

Line 1 - Magnetic Profile when the distance between the coils is >a

Line 2 - Magnetic Profile when the distance coils is =a

Line 3 - Magnetic Profile when the distance between coils is <a- Superimposition overlaps completely

Apparatus consists of the following:-

1. Digital GaussmeterRange : 0-200Resolution : 0.1GAccuracy : ± 0.5%Display : 3½ digit 7 segment LED with autopolarity.

2. Two CoilDiameter : 200 mmNumber of turn : 1000

3. Constant Current Power SupplyCurrent : 0-0.5A Smoothly adjustableLine Regulation : ± 0.2% for 10% mains variation.Load Regulation : ± 0.2 % for 0 to full loadDisplay : 3½ digit 7 segment LED Display.Protection : Against overload/short circuit.

The 2 coils are mounted on platform one coil is fixed and other coil moves smoothly on a rail along the axis of the coils.

1

2

3

Ma

gn

etic F

ield

Distance (mm)

12

18 Study of Dielectric Constant

Study of Dielectric Constant and Curie Temperature of Ferroelectric Ceramics

Dielectric or electrical insulating materials are understood as materials in which electrostic field can persist for long times. Layers of such substances are commonly inserted into capacitors to improve their perfomance, and the term dielectric refers specifically to this application.

An electric field polarizes the molecules of dielectric, producing concentrations of charge on its surface that create an electric field opposed (antiparallel) to that of capacitor. This reduces the electric potential. Considered in reverse, this means that, with a dielectric, a given electric potential causes the capacitor to accumulate a larger charge.

All ferroelectric materials have a transition point called the Curie point (T ). At T>T , c c

the crystal does not exhibit ferroelectricity, while for T<T it is ferroelectric. If there are c

more than one ferroelectric phase, the temperature at which the crystal transforms from one phase to another is called transition temperature. Near the Curie temperature point or transition temperatures, the thermodynamic properties including dielectric, elastic, optical and thermal constants show an anomalous behaviour.

The graph on the next page shows the variation of dielectric constant with temperature for Lanthanum doped Lead Zirconate Titanate (PLZT) ceramic, which is cooled from its paraelectric cubic phase to ferroelectric rhombohedral phase.

1. Probes Arrangement, DEA-01

It has two individually spring loaded probes. The probes arrangement is mounted in a suitable stand, which also holds the sample plate. To ensure the correct measurement of sample temperature, the RTD is embedded in the sample plate

Description of the Experimental Set-up

DEC-01

Perovskite ABO structure with the A3

and B cations on the corner and bodycentre positions, respectively. Three oxygenanions per unit cell occupy the faces andform octahedra surrounding the B-site.

A

B

Temp. Range

Display

Resolution

Accuracy

Stability

Power

Ambient to 200°C

3½ digit, 7 segment LED with autopolarity & decimal indication

0.1°C

±0.5°C (typical)

±0.2°C

150W

:

:

:

:

:

:

Range

Resolution

Display

50-6000 pf

1 pf


:

:

:

(ii) Digital Capacitance Meter

This is a compact direct reading Instrument for the measurement of capacitance of the sample.

6400

6200

6000

5800

5600

5400

5200

5000

4800

4600

4400

4200

4000

3800

3600

3400

3200

3000

2800

2600

2400

2200

2000

1800

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230

Die

lec

tric

Co

ns

tan

t (e

)

DIELECTRIC CONSTANTSAMPLE : Barium Titanate

T (Curie Point)C

Temperature (K)

13

just below the sample. This stand also serves as the lid of temperature controlled oven. Proper leads are provided for connection to Capacitance Meter and Temperature Controller.

2. DEC-Sample

Barium Titanate (BaTiO )3

3. Oven, DEO-01

This is a high quality temperature controlled oven. The oven has been designed for fast heating and cooling rates, which enhances the effectiveness of the controller.

4. Main Unit

The Set-up consists of two units housed in the same cabinet.

(i) Oven Controller

Platinum RTD (A class) has been used for sensing the temperature. A Wheatstone bridge and an instrumentation amplifier are used for signal conditioning. Feedback circuit ensures offset and linearity trimming and a fast accurate control of the oven temperature.

19 Planck's Constant Experiment

1. Determination of Planck's Constant and Work Function of Materials by Photoelectric Effect

It was observed as early as 1905 that most metals under influence of radiation, emit electrons. This phenomenon was termed as photoelectric emission.The experimental facts provided the strong evidence that the electromagnetic field is quantified and the field consists of quanta of energy E= hn where n is the frequency of the radiation and h is the Planck's constant. These quanta are called photons.Further it is assumed that electrons are bound inside the metal surface with an energy ef, where f is called work function. It then follows that if the frequency of the light is such that

hn > ef

it will be possible to eject photoelectrons, while if hn<ef, it would be impossible. In the former case, the excess energy of quantum appears as kinetic energy of the electron, so that

2 hn= mv + ef (1)

which is the famous photoelectrons equation formulated by Einstein in 1905.The energy of emitted photoelectrons can be measured by simple retarding potential techniques as is done in this experiment. When a retarding potential V is used to 0

measure kinetic energy of electrons E , we have, e

2E = mv = eV or V = n - fe 0 0

So when we plot a graph of V as a function of n, the slope of the straight line yields h and 0

the intercept of extrapolated point n=0 can give work function f.

2. To verify inverse square law of radiation using a photoelectric cell

If L is the luminous intensity of an electric lamp and E is the illuminanscence (intensity of illumination) at point r form it, then according to inverse square law.

E =

If this light is allowed to fall on the cathode of a photo-electric cell, then the photo-electric current (I) would be proportional to E.

E = =K.I

Hence a graph between and I is a straight line, which verify the inverse square law of radiation.

PC-101

L2r

L2r

12r

14

15

THE APPARATUS CONSIST OF THE FOLLOWING :

1. Photo Sensitive Device : Vacuum photo tube.2. Light source : Halogen tungsten lamp 12V/35W.3. Colour Filters : 635nm, 570nm, 540nm, 500nm & 460nm.4. Accelerating Voltage : Regulated Voltage Power Supply

5. Current Detecting Unit : Digital Nanoammeter It is high stability low current measuring instrument

6. Power Requirement : 220V ± 10%, 50Hz. or 110V ± 10%, 60Hz. as required.

7. Optical Bench : The light source can be moved along it to adjust distance between the light source and the phototube, scale length is 400mm. A tube is provided to install colour filter and a focus lens is fixed in the back end.

The set-up is complete in all respect, no additional accessory required.

Output

Display

Accuracy

±15V continuously variable through multi-turn pot

3 ½ digit 7-segment LED

±0.2%

:

:

:

Range

Resolution

Display

Accuracy

1000 mA, 100 mA, 10 mA & 1mA with 100 % over ranging facility

1nA at 1mA range

3 ½ digit 7-segment LED±0.2%

:

:

:

:

2

1.5

1

0.5

0

0.5

1

1.5

2

1 2 3 4 5 6 7 80

Frequency (n)-1 14

(sec X 10 )

DV = 0.810

14Dn = 1.9 X 10

h =

0.81141.9x10

-19x1.60x10

-346.82x10 Joule.sec

1.6V

eDV0

Dn

f

=

=

=

Ac

ce

lea

rtin

g P

ote

nti

al

Re

tard

ing

Po

ten

tia

l (-

V)

0

460

500

540

570

635

Fig.: Typical graph of V (stopping potential)0

as a function of n0

Fig.: Verification of Inverse Square Law2 Graph : 1/r vs I

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

Cu

rre

nt I (m

A)

0.00 1.00 2.00 3.00 4.00 5.00

20 Study of Planck’s Constant

Study of Planck’s Constant by means of LED

Several proposals to measure the Planck’s Constant for didactical purposes, using the current – voltage (I-V) characteristics of a light emitting diode (LED) have been made quite regularly in the last few years. The physical interpretation however is not completely clear and this has raised many discussions, which have been published almost with same regularity as the proposals themselves.

The present experiment is based on diode current for V<V , using the diode law.0

l = l exp [-e(V – V)/ hkT]0 0

where, e is electronic charge, k is Boltzmann constant, T is absolute temperature and h is material constant which depends on the type of diode, the location of recombination region, etc.

The correct method to determine the real height of the potential energy barrier V is 0

to directly measure the dependence of the current on temperature keeping the applied voltage V slightly below V . The idea is that the disturbance to V is as little 0 0

as possible. The slope of lnI vs. 1/T curve gives e(V – V)hk (Fig. 1). The constant h 0

is determined from I-V characteristics of the diode (Fig. 2) at room temperature from the relation

h = (e/kt) (DV/Dlnl)

Compare with previous methods, this determination of V is more precise and more 0

accurate and at the same time the physical interpretation is more transparent. The Planck’s constant is then obtained by the relation

h = e V l /c0

The wavelength (l) of the light emitted by the diode can be measured by a transmission grating spectrometer normally available in the lab.

The value of Plank’s constant obtained from this method is within 5% of accepted -34value (6.62 x 10 Joules.sec).

16

C TI E I MES IEN FIC QU P NT

ORO RKEE

PCA-01

AN S ONSTA A PARAT SPL CK' C NT P UMo l C 0de - P A- 1

V

CV - 1 - T 1E TXP TEXP

FOF

NCURRE T

S T EMPE TON

mA

mA

ON

LED

The set-up is a self contained unit. All the necessary facilities and measuring devices are built in a single unit, as a result only minimum of external connections need to be made.

[I] Dependence of current (I) on temperature (T) at constant applied voltage (V)

The following facilities are built in for this

Current Meter

A highly stable current source with 3½ digit display.Range: 0-2mA with resolution of 1mA

Oven, PCO-01

It is a small temperature controlled oven with built-in RTD sensor.Temperature adjustable from ambient to 338KDigital display of temperatureHigh stability 1K

Variable Voltage Source (0-2V)

A high stability voltage source with 3½ digit display.

[II] Material Constant h

To draw I-V characteristics of LED for determination of h, a variable voltage source and a current meter are provided with 3½ digit display.

[III] The wavelength l of light emitted by LED

These are taken from LED datasheet or measured by a transmission grating,and are provided with the set of LED’s.

Fig. 1 Fig. 2

17

T-I Characteristics I-V Characteristics

1.2

1.1

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

8

7

6

5

4

3

2

1

Sample: LED YellowAmbient Temp: T = 300KSample: LED Yellow

V = 1.8 V

DInl

DV

1.4 1.6

Junction Voltage (V)

1.8 22.8 2.9

In I (

I in

mA

)

In I (

I in

mA

)

3 3.1 3.2

DInl

-1DT

-1 -3T x 10

3.3 3.4 3.5

18

21 Franck-Hertz Experiment

In 1914 Franck & Hertz experimentally proved that the energy transferred from electrons to atoms always has discreet values and the values obtained for energy levels are in agreement with spectroscopic results. Thus experimentally proving the Bhor's Model. It is a landmark experiment and can be performed in any college lab.

The experiment consists of the following:

Argon filled tetrode

Filament Power Supply

3.6 - 4.3 continously variable

Power Supply for VG K1

1.3 - 5V continously variable

Power Supply for VG A2

1.3 - 15V continously variable

Power Supply for VG K2

0 - 95V continuously variable

Saw tooth waveform for CRO display

Scanning Voltage : 0-80V

Scanning Frequency : 115±20 Hz

Multirange Digital Ammeter

Display : 3½ digit, LED-7 -8 -9 Range : 10 , 10 & 10 A

The instrument can not only lead to a plot of the amplitude spectrum curve by means of point by point measurement, but also directly display the amplitude spectrum curve on the oscilloscope screen. This instrument can thus be used as classroom experiment as well as for demonstration to a group of students.

F H - 3 0 0 1

Nanoammeter

Fig. 1

V

V

V

G K1

G K2

G A2

A

G2

G1

K

Plot of Beam Current Vs. Accelarting Voltage

Accelarating Voltage V (V)G2K

-8E

lec

tro

n B

ea

m C

urr

en

t (A

x1

0)

1400

1200

1000

800

600

400

200

0

0 10 20 30 40 50 60 70 80 90 100

in Franck Hertz Experiment, FH-3001

47V

47V

Oscilloscope display of Franck-Hertz experiment

Ele

ctr

on

Be

am

Cu

rre

nt

Accelerating Voltage

Fig.The resistivity of a Germanium crystal as a function of inverse temperature. For this sample T<363K, conduction is due mainly to the impurity carriers

(Extrinsic Region). For T>363K, conduction is due to electrons transferred to the conduction band (and the corresponding holes created in the valence band). This

is the Intrinsic region.

0

0.1

0.2

0.3

0.4

0.5

0.5 1.0 1.5 2.0-1(T x1000)

log

r10

2.5 3.0 3.5 4.0

0.6

0.7

0.8

0.9

1.0

.325

0.5

68

363K

Eg

2k

Eg

1T

Log re

-50.568 x 2.3026 x 8.6 x 10 x 2-30.325 x 10

( )

= 0.69 eV

=

22 Four Probe Experiment

Resistivity of Semiconductors by Four Probe Method at DifferentTemperatures and Determination of the Band-gap (Basic Model)


(i) Four Probe Arrangement, FPA-02 : It has four individually collinear, spring loaded probes. The probes are mounted in a teflon bush, which ensures a good electricalinsulation between theprobes and maintainsthem at equal distance.The whole arrangementis mounted on a suitablestand and leads areprovided for the current& voltage measurements.

(ii) Oven FPO-02 (upto 200°C)

(iii) DFP-02 Sample (Ge-n type)

(iv) Thermometer DFP 02-THR (0 - 150°C)

(v) Four Probe Set-up, DFP-02

(a) Multirange Digital Millivoltmeter

Range

Resolution

Accuracy

Impedance

Display

(b) Constant Current Generator

Open Circuit

Current Range

Resolution

Accuracy

Load Regulation

Line Regulation

(c) Oven Power Supply : Built-in for the above oven.

D F P - 0 2

:

:

:

:

:

X1 (0-200mV)and X10 (0-2V)

100mV at X1 range

±0.1% of reading ±1 digit

1 Mohm


18V

0-20mA

10mA

±0.25%

±0.1% for no loadto full load

±0.1% for 10% changes

:

:

:

:

:

:

19

Resistivity of Semiconductor by Four Probe Method at DifferentTemperatures and Determination of the Band-gap (Advance Model)

Description of the experimental set-up

1. Probes Arrangement, FPA-03

It has four individually spring loaded probes. The probes are collinear and equally spaced. The probes are mounted in a teflon bush, which ensures a good electrical insulation between the probes. A teflon spacer near the tips is also provided to keep the probes at equal distance. The probe arrangement is mounted in a suitable stand, which also hold, the sample plate. To ensure the correct measurement of sample temperature, the RTD is embedded in the sample plate just below the sample. This stand also serves as the lid of the temperature controlled oven. Proper leads are provided for the current and voltage measurements.

2. DFP 03-SAMPLE

Germanium crystal in the form of a chip.

3. OVEN, FPO-03

This is a high quality temperature controlled oven suitable for Four Probe Set-up. The oven has been designed for fast heating and cooling rates, which enhances the effectiveness of the controller.

4. FOUR PROBE SET-UP, DFP-03

The set-up consists of three units housed in the same cabinet.

(i) Oven Controller

Platinum RTD (A class) has been used for sensing the temperature. A wheatstone bridge and an instrumentation amplifier are used for signal conditioning. Feedback circuit ensures offset and linearity trimming and a fast accurate control of the oven temperature.

23 Four Probe Experiment D F P - 0 3

20

FOUR PROBE SET-UP Model DFP-03

RANGE

ON OFF

SET TEMP RTD OVEN VOLTAGE CURRENT CURRENTADJ.

mV

mA

X1 X10OVEN CONTROL

K

C ENTI C E UI ME TS I FI Q P N

OORK ER E

D A OIGIT L MICR VOLTMETER

M d 1o el DMV - 00

C NS ANT NT O CEO T CURRE S UR

de S 0Mo l : CC - 1

PID CONTROLLED OVENModel : PID-200

S I I E PC E T F C Q I ME T

N I U N

R O KO R EE

CS IENTIFIC EQUIPMENTRO RKEEO

SCIENTIFIC EQUIPMENTROORKEE

24 Four Probe Set-up DFP - RM(Research Model)

Four Probe Set-Up for Measuring the Resistivity of Very Low toHigh Resistivity Samples at Different Temperatures


The probe arrangement is mounted in a suitable stand, which holds the sampleplate and RTD (A class) sensor.

1. Probes Arrangement, FPA-RM:

21

Temperature Range : Ambient to 473KStability : ±0.5K

Measurement Accuracy : ±1K (typical)Oven : Specially designed for Four Probe Set-UpDisplay : 3½ digit, 7 segment LED with autopolarity and

decimal indication

(ii) Multirange Digital Voltmeter

Range : X1 (0-200mV) & X10 (0-2V)Resolution : 100mV at X1 rangeAccuracy : ± 0.1% of reading ± 1 digitDisplay : 3½ digit, 7 segment LED with autopolarity and

decimal indicationOverload Indicator : Sign of 1 on the left & blanking of other digits.

(iii) Constant Current Generator

Open Circuit Voltage : 18VAccuracy : ± 0.25% of the reading ± 1 digitCurrent range : 0 - 20 mAResolution : 10 mALoad regulation : ± 0.1% for 0 to full loadLine regulation : 0.1% for 10% changes

The experimental set-up is complete in all respect

2. PID Controlled Oven, PID-200

Specifications of the Oven

Temperature Range

Resolution

Short Range Stability

Long Range Stability


Oven, FRO-RM

3. Constant Current Source

a) Constant Current Source, CCS-01 (for low resistivity sample)

This current source is suitable for the resistivity measurement of low to mediumresistivity samples such as thin films of metals/alloys and semiconductors suchas Ge.

Specifications

Open Circuit Voltage

Current Range

Resolution

Accuracy

Display

Load Regulation

Line Regulation

b) Low Current Source, LCS-02 (for high resistivity samples)

4. D.C. Microvoltmeter, DMV-001 (Item No. 1).

: 12V

: 0-20mA & 0-200mA (continuously variable)

: 10mA at 0-20mA range

: ±0.25% of the reading

: 3½ digit, 7 segment LED

: ±0.1% for 0 to full load

: ±0.1% for 10% changes

Ambient to 200°C

0.1°C

±0.2°C

±0.5°C

±0.5°C (typical)

Specially designed for Four Probe Set-Up


:

:

:

:

:

:

:

22

This current source is especially suitable for the resistivity measurement ofpolymer films, conducting ceramics and Si crystals.

Specifications

Open Circuit Voltage

Current Range

Resolution

Accuracy

Display

Load Regulation

Power

: 15V (min.)

: 0-2mA, 0-20mA, 0-200mA & 0-2mA

: 1nA at 0-2mA range

: ±0.25% of the reading ±1 digit

: 3½ digit, 7 segment LCD with auto polarity

: ±0.1% for 0 to full load

: 3 x 9V batteries

Display

26 Magnetoresistance Set-up

Measurement of Magnetoresistance of Semiconductors

The resistance of the sample changes when the magnetic field is turned on. The phenomenon, called magnetoresistance, is due to the fact that the drift velocity of all carriers is not same. With the magnetic field on; the Hall voltage V = E t = |v x H| compensates y

exactly the Lorentz force for carriers with the average velocity; slower carriers are over compensated and faster one undercompensated, resulting in trajectories that are not along the applied field.

Introduction

The Four Probe Method is one of the standard and most widely used method for the measurement of resistivity. In its useful form, the four probes are collinear. The error due to contact resistance, which is significant in the electrical measurement on semiconductors, is avoided by the use of two extra contacts (probes) between the current contacts. In this arrangement the contact resistance may be high compared to the sample resistance, but as long as the resistance of the sample and contact resistance’s are small compared with the effective resistance of the voltage measuring device (potentiometer, electrometer or electronic voltmeter), the measured value will remain unaffected. Because of pressure contacts, and 2-way motion, the arrangement is specially useful for quick measurement on large samples at room temperature.

Easy resistivity mapping of large sample

2 – way movement with vernier scales(0.01mm)

Spring loaded contacts for firmconnections

Features

Four Probe Set-up for mapping the resistivity of large samples

Accessories required

1. Constant Current Source, CCS-01 (on page 22)

2. Low Current Source, LCS-02 (on page 22)

3. D.C. Microvoltmeter, DMV-001 (Item no. 1, on page 3)

23

25

M R X - 0 1

MAGNETORESISTANCE SET-UPModel : DMR-01


mA

mV

Current Voltage

ON

Four Probe Set-up (Mapping) F P - 0 1This results in an effective decrease of the mean free path and hence an increase in resistivity. Here the above referred symbols are defined as: v = drift velocity; E = applied electric field; t = thickness of the crystal; H = Magnetic field. The set-up consists of the following:

(1) Four Probe arrangement, MRA-01

It consists of 4 collinear, equally spaced (2mm) and individually spring loaded probes mounted on a PCB strip. Two outer probes are for supplying the constant current to the sample and two inner probes for measuring the voltage developed across these probes. This eliminate the error due to contact resistance which is particularly serious in semiconductors. A platform is also provided for placing the sample and mounting the Four Probes on it.

(2) MR-Sample

Ge Crystal (n-type) dimensions: 10 x 10 x 0.5mm

(3) Magnetoresistance Set-up, DMR-01

This unit consists of a digital millivoltmeter and constant current power supply. The voltage and probe current can be read on the same digital panel meter through a selector switch.

24

(4) Electromagnet, EMU-50V (Item No. 7, on page 6)

(5) Constant Current Power Supply, DPS-50 (Item No. 7, on page 6)

(6) Digital Gaussmeter, DGM-202 (Item No. 9/8, on page 7/6)

(b) Constant Current Power Supply

Specifications:

Current

Accuracy

Load regulation

Line regulation

: 0-20mA (10mA min.)

: ±0.2% of the reading ±1 digit

: 0.1% for 0 to full load

: 0.2% for 10% variation

(a) Digital Millivoltmeter

Specifications: Range

Accuracy

: 0-200mV(100mV min.)

: ±0.1% (±1 digit)

Magnetoresistance of a Ge CrystalDr/ro vs. Magnetic Field (H)

Dr/r

o

0.036

0.032

0.028

0.024

0.020

0.016

0.012

0.008

0.004

0.0000.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Magnetic Field (KG)

5.0 5.5

27 Two Probe Setup

Two Probe Method for resistivity measurement of insulatorsat different temperatures

25

Oven(TPO-01)

Sensor

Display

Power

Specially designedfor Two Probe Set-Up

RTD (A class)

3½ digit, LED

150W

:

:

:

:

Temperature Range

Resolution

Short Range Stability

Long Range Stability


Ambient to 200°C

0.1°C

±0.2°C

±0.5°C

±0.5°C (typical)

:

:

:

:

:

3. High Voltage Power Supply, Model EHT-11 (Item No. 4, on page 4)

4. Digital Picoammeter, Model DPM-111 (Item No. 3, on page 4)

The experimental set-up is complete in all respect

The Two Probe Method is one of the standard and most commonly used method for the measurement of resistivity of very high resistivity samples - near insulators. The resistivity measurement of such samples is beyond the range of Four Probe Method.

DESCRIPTION OF THE EXPERIMENTAL SET-UP

1. Two Probes Arrangement, TPA-01

It has two spring load contact probes. These probes move in a pipe and are insulated by teflon washers. This probes arrangement is mounted in a suitable stand, which also holds the sample plate and RTD sensor. The stand also serves as the lid of PID Controlled Oven. Teflon coated leads are provided for connecting with High Voltage Power Supply EHT-11 and Digital Picoammeter DPM-111. With

-12this set-up assuming max. voltage = 1500V; current 100x10 A (max) and thickness of sample 1mm, the resistivity of the sample could be measured upto

1410 ohm.cm.

2. PID Controlled Oven, PID-200

This is a high quality temperature controlled oven suitable for Four Probe Set-up. The oven has been designed for fast heating and cooling rates, which enhances the effectiveness of the controller. While the basic design of the controller is around the PID configuration for its obvious advantages, wastage of power is avoided by using a Pulse Width Modulated (PMW) switch. This combination has the advantages of both on-off controller and linear PID controller. The result is a stable and accurate temperature control.

Platinum RTD has been used for sensing the temperature. A wheatstone bridge and an instrumentation amplifier are used for signal conditioning. Feedback circuit ensures offset and linearity trimming to a great degree of accuracy. The set and measured temperature are displayed on 3½ digit DPM through selector switch.

IGITAL MIC OVOLTM TERD

R E

M DE DMV 00O L - 1

N TA U E O CCO S NT C RR NT S UR E

D . 01MO EL NO CCS-

PID CONTROLLED OVENModel : PID-200

IME T

SCE NTI IC EQUIP NF

R EROO KE

SCI I E P NTENTIF C QUI ME

ROORKEE


TPX-01

Fig. 1 : Block diagram of the ESR set-up

DPPH

OSCILLOSCOPE

HELMHOLTZ COIL

50 HzSWEEP UNIT

50 HzPHASE SHIFTER

X

Y

R.F.OSCILLATOR

DETECTORA.F.

AMPLIFIER

Electron Spin Resonance Spectrometer28

26

In this method, use is made of the Zeeman interaction of the magnetic dipoles associated with the nucleus or the electron, when placed in an external magnetic field. Accordingly, they are identified as NMR (Nuclear Magnetic Resonance) or ESR (Electron Spin Resonance). This form of spectroscopy finds many applications in many diverse branches of Physics, Chemistry and Biology.

This set-up is designed, keeping in mind the basic objectives of a classroom experiment. The observation of ESR in low magnetic field and in a radio frequency makes this apparatus very simple, inexpensive and within reach of every Post Graduate laboratory.

The Electron Spin Resonance experiment comes complete along with following accessories:

(i) Helmholtz coils with an attachment for the ESR-HC

(ii) ESR Sample: DPPH

(iii) R.F. Oscillator (10MHz to 19MHz)

The trace shows the resonancewhen the electron's precession

matches the oscillator frequency

ESR-104

Fig. A Glow Curve of the luminescent material(KCI crystal), the heating speed is 11K/min

T (K)

T =355KG

INT

EN

SIT

Y I (

nA

)

293273

10

0

20

30

40

50

60

70

80

90

313 333 353 373 393

29 Study of Thermoluminescence of F-centers

27

Study of Thermoluminescence of F-centers in Alkali Halide Crystals

Introduction

A colour centre is a lattice defect that absorbs visible light. These colour centers can be produced by heating the crystal in excess of alkali vapour or by irradiation. The colour centers formed due to trapped electrons or trapped holes can be destroyed (bleached) by illuminating with light or warming. Important information about the colour centers can be obtained from the plot of luminescence intensity vs. temperature, taken at a constant heating rate called glow curve. It may contain one or many glow peaks, depending upon whether there are one or several different kinds of traps.

The experiment consists of the following :

(a) Experimental set-up for creating Thermoluminescence

(1) Sample: KBr (TLS-KBr) and KCl (TLS-KCl) single crystal

(2) Thermoluminescence Temperature Meter, TL-02

• Digital Thermometer with RTD sensor

• Oven power supply

(3) Sample holder

(4) Thermoluminescence Oven (upto 423K), TLO-02

(5) Black Box, TL-BBx

(b) For measurement of Luminescence Intensity

(1) Photomultiplier tube 931A, TL-PMT

(2) PMT Housing with biasing circuit and connecting coaxial cables, TL-PMH

(3) High Voltage Power supply, EHT-11(Item no. 4, on page 4)

(4) Digital Nanoammeter, DNM-121 (Item no. 2, on page 3).

TLX-02 30 Hall Effect Experiment

28

The resistivity measurements of semiconductors cannot reveal whether one or two types of carriers are present; nor distinguish between them. However, this information can be obtained from Hall Coefficient measurements, which are also basic tools for the determination of carrier destiny and mobilities in conjunction with resistivity measurement.

The Hall effect experiment consists of the following:

a) Hall Probes (HPN-21, HPP-21)

Hall Probe (Ge Crystal)

Material : Ge single crystal n or p-type

Resistivity : 8-10 Wcm.

Contacts : Spring type (solid silver)

Zero-field potential : <1mV (adjustable)

Hall Voltage : 35-60mV/10mA/KG

b) Hall Effect Set-up, DHE-21, Consists of the following

(i) Digital Millivoltmeter

Range : 0-200mV(Resolution 100mV)

Accuracy : ±0.1% of reading±1 digit

Impedance : 1 Mohm

Display : 3½ digit,7 Segment LED

c) Electromagnet, EMU-50/ EMU-75 (Item no. 7/6, on page 6/5)

d) Constant Current Power Supply, DPS-50/ DPS-175 (Item no. 7/6, on page 6/5)

e) Digital Gaussmeter, DGM-202/ DGM-102 (Item no. 9/8, on page 7/6)

The experiment is complete in all respect.

(ii) Constant Current Generator

Currents : 0-20mA (Resolution 10mA)

Display : 3½ digit, 7 segment LED

Accuracy : 0.25%; ±1 digit

Load : 0.05% for no load toRegulation full load

Line : 0.05% for±10% changesRegulation

T C QU ES I N F E I M T

C E I I P N

ROOK EERSC E I I EQI MEN

I NT F C U P TO KRO R EE

HEX-21

Hall Effect enables the charge carrier concentration and mobility to be determined by experiment. Direction of the Hall Voltage in silver indicates negative charge carriers, which is in agreement with concepts of the model of the ‘free electron gas‘. Limitations of this model are shown by the so called ‘abnormal Hall Effect’ of tungsten. The experiment carried out under identical conditions for tungsten show the Hall Voltage to have about same magnitude but opposite direction as in silver.

This can be explained by the ‘Energy Band diagram’. The tungsten atom has 2 6 4 2…….5s 5p 5d 6s electronic structure.

When the atoms come close together to form the solid, the close lying states 5d and 6s broaden into bands, with s band broadening considerably more than the d band. This is because of the larger size of the s orbital. The figure schema-tically shows the allowed energies as a function of the interatomic distance. The number of allowed states is ten per atom in the d band and two in the s band. In tungsten there are six electrons to be shared between these two bands. The result is that at the interatomic distance in tungsten there are holes in the d band and electrons in the s band, making tungsten predominantly a hole conductor.

This sort of mixed (electrons and holes) conduction is a general characteristic of transition metals

The apparatus consists of the following:

Fig.: Allowed energies as a function of interatomic distance (d)

b) Hall Probe-Tungsten (HP-W)

Material : Tungten Strip(8 x 6 x 0.05 mm)

Contacts : Press type for current Spring Type for Voltage

Hall Voltage : ~15 mV/10A/10KG

a) Hall Probe-Silver (HP-Ag)

Material :Silver Strip(8 x 6 x 0.05 mm)

Contacts :Press type for currentSpring Type for Voltage

Hall Voltage :~17 mV/10A/10KG

31 Hall Effect in Metals HEM-01

29

E

5d

6s

1/d

HALL EFFECT IN METALSample thickness : 0.05 mm

Magnetic Field (KG)

30

c) High Current Power Supply, Model PS-20A

Range : 0-20A continuosly variableAccuracy : ±0.5%Regulation : ±0.5% for ±10% variation of mainsDisplay : 3½ digit, 7 Segment LED

d) Digital Microvoltmeter, DMV-001 (Item no. 1, on page 3)

e) Electromagnet, Model EMU-75T

Pole Peices : 75mm tappered to 25mm Mag. Field : 17KG 10mm airgap

f) Constant Current Power Supply, Model DPS-175 (Item no. 6, on page 5)

g) Gaussmeter, DGM-202/ DGM-102 (Item no. 7/6, on page 7/6)


±5% at Energising Coils : Two of approx. 13W eachPower : 0-90Vdc, 3A, for coils in series

0-45Vdc, 6A, for coils in parallel

-60

-50

-40

-30

-20

-10

0

10

20

30

40

50

60

0 2 4 6 8 10 12 14 16 18 20

Ha

llV

olt

ag

e(

V)

I=19A

I=13A

I=7A

I=7A

I=13A

I=19A

Silver

I = Probe Current

m

Tungsten

32 Dependence of Hall Coefficient on Temperature

31

The Hall voltage for p-carriers has opposite sign from that for n-carriers. Therefore if a semiconductor with p-type doping is gradually heated up, more and more electrons from its valence band will go to conduction band. As a result hall voltage would fall rapidly with temperature and even become zero or change sign. At the point of zero Hall Coefficient, it is possible to determine the ratio of mobilities b=m /m . The Hall coefficient e h

inversion is a characteristic of only p-type semiconductors.

The set-up consists of the following. The Hall Probe comes complete with

1. Hall Probe (Ge: p-type), HPP-22

Ge single crystal with four spring type pressure contacts is mounted on a glass-epoxy strip. Leads are provided for connections with the current source andHall voltage measuring devices.

Oven

It is a small oven which could be easily mounted over the crystal or removed if required.

Temperature Sensor

Cromel-Alumel thermocouple with its junction at a distance of 1mm from the crystal.

2. Hall Effect Set-up :DHE-22

The set-up, DHE-22 consists of two sub set-ups, each consisting of further two units.

Measurement of Probe Current & Hall Voltage

This unit consists of digital millivoltmeter and constant current power supply. The Hall voltage and probe current can be read on the same digital panel meter through a selector switch.

(a) Digital Millivoltmeter

SpecificationsRange : 0-200mV (100mV min.)Accuracy : ±0.1% of reading ±1 digitImpedance : 1MW


SpecificationsCurrent : 0-20mA (10mA min)Accuracy : ±0.2% of the reading or ±1 digitLoad regulated : 0.05% for 0 to

full loadLine regulation : 0.05% for 10%

variation

Dependance of Hall Coefficient on TemperatureSample: Ge (p-type) medium doping (Hall Probe with small oven)

3-1

Ha

ll C

oe

ffic

ien

t x 1

0 (

cm

co

ulo

bm

)

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0

-2

-40 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 115

0Temperature ( C)

HEX-22

SCIE EQUIPMENT

ORKEE

HALL EFFECT SET-UPModel : DHE-22

Hall Voltage (mV)

Probe Current (mA)

PROBECURRENT

HALLVOLTAGE

PROBEHEATER

CURRENTTHERMO

E.M.F.

ZE J. ON

Thermo e.m.t. (mV)

Heater Current (mA)

32

Apparatus for the Measurement of Susceptibility of Paramagnetic Solution by Quinck’s Tube MethodThe force acts on any substance when it is placed in a inhomogeneous magnetic field. This force depends on he susceptibility c, of the material, i.e., on ratio of intensity of magnetisation to magnetising field (I/H). Quantitatively it refers to the extent of induced magnetisation in unit field. The force acting on a substance, either of repulsion or attraction, can be measured with the help of an accurate balance in case of solids (Gouy's Method) or with the measurement of rise in level in a narrow capillary in case of liquids. From this measurement, the value of susceptibility can be calculated.

The apparatus consists of the following:

(a) Quinck’s tube, QTT-01, Quink Tube Stand (QTS-01)

(b) Sample: MnSO .H O4 2

(c) Electromagnet, EMU-50T / EMU-75T (Item no. 7/6, on page 6/5)

(d) Constant Current Power Supply, DPS-50 / DPS-175 (Item no. 7/6, on page 6/5)

(e) Digital Gaussmeter, DGM-202 (Item no. 9/8, on page 7/6)

(f) Travelling Microscope, TVM-02 (Item no 13, on page 9)

Note : For substances like MnSO .H O/ FeCl , EMU-50T is sufficient, but for substances like 4 2 3

water EMU-75T is required.

33 Quinck’s Tube Method

Measurement of Thermo emf and Heater current

The unit consists of a digital millivoltmeter and constant current power supply. The thermo emf of thermocouple and heater current can be read on the same DPM through a selector switch.(a) Digital Millivoltmeter

Specifications :Range : 0-20mVResolution : 10mV equivalent to 0.25°C in terms of thermo emfAccuracy : ±0.1% of reading ±1 digit


Specifications :Current : 0-1AAccuracy : ±0.2% of the reading ±1 digitLine regulation : 0.1% for 10% variationLoad regulated : 0.1% for 0 to full load

5. Electromagnet, EMU-50V (Item No. 7, on page 6)

6. Constant Current Power Supply, DPS-50 (Item No. 7, on page 6)

7. Digital Gaussmeter, DGM-202/ DGM-102 (Item No. 9/8, on page 7/6)


QTX-01

In the Gouy method of susceptibility measurement, the solid sample in the form of a long cylinder (area of cross section A) is hung from the pan of a balance and is placed such that one end of the sample is between the pole-pieces of the magnet (field H ) and the other one is outside the field. The force exerted on the sample by the inhomogeneous magnetic field is obtained by measuring the apparent change (Dm ) in the mass of the sample. The susceptibility c is given by

2 c = 2Dmg/AH

If the sample is in the form of powder, it is filled in a long nonmagnetic tube which is then suspended from the pan of the balance.

The set up consists of the following:

(a) Scientific Balance, KSB-07

Capacity : 200 gms Sensitivity : 1/10 mg. by vernier Beam : Hard Bronze/ Brass Arrestment : Circular, falling away type Air Damping : Very quick and positive, beam coming to rest in 2-3 secCahinomatic Device : A gold plated chain is suspended from the beam with its other end

screwed on the rotating drum on which a scale graduated from 0 to 10 div each division representing 1mg is installed. By the movement of this scale before a vernier, reading upto 1/10th mg is taken

(b) Sample in the form of a long rod:

Set of 4 samples, 2 each of Ebonite and Wood

(c) Electromagnet, Model EMU-75TPole Peices : 75mm tappered to 25mm Mag. Field : 22KG mm airgap

(d) Constant Current Power Supply, Model DPS-175 (Item no. 6, on page 5)

(e) Gaussmeter, Model DGM-202 or DGM-102(Item no. 9/8, on page 7/6)


at 5Energising Coils : Two of approx. 13W eachPower : 0-90Vdc, 3A, for coils in series

0-45Vdc, 6A, for coils in parallel

34 Gouy's Method GMX-01

33

Schematic Diagram Gouy’s Balance Experiment

A precise knowledge of various magnetic parameters of ferromagnetic substances is an important aspect of magnetic studies. These magnetic properties can be obtained from a magnetic hyteresis loop, which can be obtained by a number of methods. Some of these require samples in ring form, others can be used with films or even rock samples. Ring form samples are not always practical to make while in others, demagnetization effect sometime becomes important.

The present set-up can accept samples of thin wires. The effects of demagnetization, sample diameter and eddy currents have been taken into account.

Besides coercivity, saturation magnetization and retentivity, this set-up can also indicate the number of phases present.

The following magnetic properties of ferromagnetic sample can be studied, with this apparatus.

Coercivity Saturation magnetisation Retentivity Hyteresis loss

The number of phases present

The set-up is complete in all respect, including long solenoid, its power supply with a panel meter directly calibrated in gauss, sample holder with a pick-up coil and a set of samples: hard steel, soft iron and nickel (all in wire form). A measuring CRO will however be required.

35 Magnetic Hysteresis Loop Tracer

34

Fig. 1 J-H Loop Fig. 2 dJ/dt Loop 2 2Fig. 3 d J/dt Loop

LO ERHYSTERESIS OP TRACM el L Iod H T-II

SC E I U PMENI NT FIC EQ I T

OO KR R EE

HLT-111

36 Study of P-N Junctions

35

Study of the Energy Band-Gap and Diffusion Potential of P-N Junctions

This is an advanced level experiment to be performed on commercially available diodes viz. germanium or silicon diodes, various types of LED’s and also on the base-emitter/ collector-base junctions of a transistor. The results of the experiments not only give the device characteristics but also provide an insight into the properties of the materials used in the fabrication of the junction. In the set-up, all the necessary instrumentation is integrated as a result of which a minimum of external connections need to be made by the user. A CRO is the only accessory that is required.

The following studies can be carried out.

(i) Reverse saturation current l and 0

material constant h

(ii) Temperature coefficient of junction voltage dV/dt

(iii) Energy band-gap VG0

(iv) Junction capacitance

The experimental set-up consists of the following:

(1) Study of P-N Junctions, Model PN-1

(a) 3½ digit DPM for current/ temperature measurement.

(b) 3½ digit DPM for bias voltage/ junction voltage measurements.

(c) To connect the diode – one for experiment 1 & 2 and other for experiment 3.

(d) Two fixed frequency oscillators (5KHz & 20KHz) with the same output (200mV).

8

6

4

2

0

- 2

- 4

- 6

- 8

- 10

- 120.5 1 1.5 20

10

Fig. 1 Reverse Saturation Current

Junction Voltage (V)

h =

=

q

191.602 x 10- x 0.18-231.38 x 10 x 298 x 4.55

InI 0

InI

(I in

mA

)

I 0

= - 10.9

= -100.19 x 10 A

DV

Dln

I =

4.5

5

= 0.18

= 1.54

DV

kT

PN-1

DInI

Jun

ctio

n V

olta

ge

(V

)

0.8

0.7

0.6

290 310 330 350 370

Temperature (K)

Fig.2 Temperature Dependence

of Junction Voltage

SAMPLE: BC109

(BASE-EMITER JUNCTION)

=1.00 mA

(Constant for the set)

0.5

I

STUDY OF P-N JUNCTION MODEL PN-1

JUNCTIONCAPACITANCE

5 KHz 20 KHz

IN OUT

C.R.O.

BIAS VOLTAGE

BIAS JUNCTION

CURRENT

V

CURRENT TEMP

TEMP

ON

MAINS

ON

OVEN

mA

K

37 Semiconductors Diodes Characteristics

36

(2) Fast temperature controlled oven

with sensor, PNO-01

(3) PNJ-Sample

(a) Transistor BC109 (base-emitter)-Si

(b) Transistor AC128 (base-emitter)-Ge

(c) Diode: IN 5408/IN 4002-Si

The unit is supplied complete with a detailed instruction manual. Sufficient theoretical description is included for a proper understanding. This is followed by a step-by-step procedure and a typical set of readings and results.

The set-up is complete in all respect, except a CRO which is required for measurement of junction capacitance. Typical results obtained are shown in fig. no. 1, 2 & 3.

The set-up is

provided with a

booklet which

contains its theory of

operation,

description,

suggestions and

discussion of the

experiments that may

be performed with it.

Forward and reverse characteristics of Ge, Si diodes and LEDs

Study of Zener diode characteristics

CRO display of forward and reverse characteristics

CRO Display

80

70

60

50

40

30

202 4 6 8 100

Ca

pa

cita

nce

(pf)

Bias Voltage (V)

Depletion Layer Capacitance as a

Function of Reverse Bias Voltage

SAMPLE Si DIODE 1N4007

Fig. 3

Graph

24

20

16

12

8

4

0

Cu

rre

nt (m

A)

Voltage (V)

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

SDC-02

38

39

Study of a Transistor Amplifier (RC Coupled)Cum Feed-Back Amplifier

Study of Multivibrators

37

The following studies can be carried out with this set-up:

1. Study of the basic circuit of a RC Coupled Amplifier.

2. Frequency response of RC Coupled Amplifier.

3. Effect of negative feedback on the gain and frequency response of the amplifier.

4. Effect of positive feedback on the gain and frequency response of the amplifier.

5. Verification of the condition of oscillation.

6. Study of different classes of amplifier.

Accessories Required

(i) A.F. Oscillator (ii) True RMS A.C. Millivoltmeter, ACM-102(Item No. 5, on page 5)


(i) Free Running vibrator

(ii) Univibrator

(iii) Bistable Multivibrators

(iv) Regulated Power Supply.

The free running multivibrator also serve as a pulse generator for the study of bistable multivibrator and univibrator.

Accessories Required

(i) Oscilloscope

RC-01

MV-01

40

41

Characteristics of Semiconductor Diodes

Study of Hybrid Parameters of a Transistor

38

The experimental set-up consists of the following:

1. Diodes: 1N4007, 1N34, 5.1V Zener and LED.

2. 3½ digit DPM for voltage measurement.

3. Precision resistances for measurement of forward and reverse current.

4. IC regulated power supply.


1. Forward and reverse characteristics of both Ge, Si diodes & LED’s.

2. Study of Zener diode characteristics.

The following studies can be carried out with this set-up.

1. Study of h parameter (input 11

impedance parameter).

2. Study of h parameter (output 22

admittance parameter).

3. Study of h parameter (forward 21

current transfer ratio).

4. Study of h parameter (reverse 12

voltage feedback ratio).

The experimental set-up is provided with a built-in power supplies and is complete.

Accessories Required:

(i) A.C. Millivoltmeter with built-in 1KHz Oscillator, ACM-103 (Item no. 5, on page 5)

(ii) Multimeter.

D-1

HP-01

42

43

44

Study of a Solid State Power Supply

Study of a Modulation and Demodulation with

Built-in Carrier Frequency Source (Solid State)

Study of Basic Operational Amplifier, Type-741

39

The following studies can be carried out with this set-up.

1. Study of rectification:

(a) Full wave rectification(b) Half wave rectification

2. Study of ac component (Ripples):

(a) Efficiency of various typeof filters – p, T type etc.

(b) The effect of load(c) The effect on regulation.

3. Regulation characteristics:

(a) The effect of load on regulation(b) The effect of change in main’s

voltage.

Accessories Required : (i) Multimeter; (ii) Oscilloscope


1. Carrier signal testing.

2. Variation of modulated wave with the modulation signal.

3. Study of detector circuit.

The experimental set-up is provided with a built-in power supply.

Accessories Required :

(i) Function Generator (Item No. 16)

(ii) Oscilloscope

The following studies can be carried out:

(i) Working of the basic circuit

(ii) Measurement of bias and offset currents

(iii) Study of inverting and non-inverting configurations

(iv) Study of Amplifier drift.

SSPS-01

MD-1

741-01

45

46

47

Study of 741 Applications

Study of Astable & Monostable Multivibratorusing Timer IC, Type-555

Study of an Integrated Circuit Regulator, Type-723

40

Features

Study of linear and non linear applications as:

– Integrator– Differentiator– Summer– Subtractor– Voltage to Current converter– Current to Voltage converter– Astable Mode– Precision rectifier

Built-in power supply

Built-in square wave and triangular wave Generator

Built-in current source.


(i) Operation as a free running multivibrator

(ii) Operation as a monostable multivibrator

(iii) Operations as a preset time delay.

Accessories Required:

(i) Oscilloscope


(i) Study of a voltage regulator

(ii) Study of a current regulator.

The experimental set-up consists of an IC 723 with facilities for convenient connections, an unregulated power supply, voltmeter, an ammeter and all the other components required to perform the experiments.

741-02

555

723

After his M.Sc. (Physics) from Allahabad University and Ph.D. from Calcutta University, Dr. Anand Prakash joined the California Institute of Technology, Pasedena, as a faculty member. During the period (1965-69), he worked on the crystal structures of various high pressure forms of ICE (ii to ix) by X-ray Diffraction and later by Neutron Diffraction at High Flux Beam Reactor at Brookhaven National Lab., N.Y. He also worked in the McMaster University, Canada on the crystal structure of alkoloids (1969-71). On returning, he joined the University of Roorkee, Roorkee. There he realized the need of new experiments in Physics which could bring insight into the subject and improve the quality of teaching. The present catalogue represents his 38 years of efforts in this direction. All the products here are designed and manufactured indigenously.

Dr. R. Mitra did his Ph.D. in the area of Control System in 1976 after completing his earlier education at IIT Kharagpur, University of Allahabad and University of Lucknow. Besides post dectoral work at DFVLR lab. in West Germany, he had been in the faculty of Dept. of Systems and Control, University of Technology, Baghdad and Thapar Engineering College, Patiala. For the past 32 years Dr. Mitra is with the Department of Electronics and Computer Engineering, IIT, Roorkee, teaching various courses in the areas of control systems, electronic instrumentation and microprocessor application. Dr. Mitra had been associated with us for over 30 years of teaching and research experience that we have been able to develop and perfect most of the equipment listed in this catalogue. Besides it is to his efforts that we have been able to diversity in the area of automatic control system, now providing about a dozen control experiments for engineering students.

Dr. Anand Prakash,Founder Chairman

Dr. R. Mitra,Chief Consultant

Control Laboratory, Instrumentation Lab, Measurement Lab Experimentsare also available

For further details contact our sister concern

261/16 Civil Lines, Roorkee -247 667, IndiaPh. : 91-1332-272852, Fax : 91-1332-274831E - mail : [email protected] us at http://www.sestechno.com

Formerly known as Scientific Equipment & Services, we have the pleasure of introducing ourselves as a reputed manufacturers of complete laboratory experiments and precision measuring instruments for BS and MS laboratories of Physics and Electronics.

For the last 39 years, we have been catering to the needs of over 1200 institutions in over 32 countries. We, while orienting ourselves to the need of laboratories have been trying our best to develop and introduce progressively more advanced laboratory experiments and general-purpose measuring instruments.

Our strict quality control ensures uncompromising quality of our instruments, low overheads and direct sales to the customers have enabled us to keep our rates very affordable.

The product catalogue highlights some of our manufacturing activities. The technical specifications given here are meant to give an accurate statement of performance of instruments manufactured by us.

We at SES Instruments Pvt. Ltd.(Formerly Scientific Equipment & Services), are greatful to the staff of IIT-Roorkee, particularly Professor K.C. Mittal, and Professor M.K. Srivastava, for their tremendous support all through these years by giving innovative suggestions and constructive criticism thereby helping in constantly adding new products and improving the existing ones.

All our products are manufactured under high level of quality control. They are warranted free from defects for a period of one year from the date of purchase. We will repair or replace as find suitable, any piece of defective equipment during this period. Even after this period after sales service is undertaken at very nominal charges.

Specifications of all products are subject to change without notice. SES Instruments Pvt. Ltd. reserves the right to make improvements to the products without incurring any obligation to incorporate these changes in products previously sold.

Equipment in this catalogue are designed to operate from 220V ±10%, 50Hz. All the equipment are also available for use with 110V ±10%, 60Hz power at no additional cost.

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SESES IS Insnstrutrumentsnts Pv Pvt. Lt. Ltd.td.3.imimg.com/data3/KE/MK/MY-526573/ses-catalogue.pdf · Magnetic Hysteresis Loop Tracer: HLT-111 34 36. Study of P-N Junctions (Bandgap