ＴＳ０２－０２１８

ＩＮＳＴＲＵＣＴＩＯＮ ＭＡＮＵＡＬ

ＦＯＲ

CAPACITIVE LEVEL MEASUREMENT

ＭＯＤＥＬ：ＣＭ

ＭＯＤＥＬ：ＣＭ－Ｐ１

－ADD 1 －

Read and understand this manual for safely usage.

･ This manual describes the product of explosion-proof construction. Read the other manuals for the product of standard specifications.

･ This manual describes the handling, inspection, and adjustment of the product which model is mentioned on the cover page. Read and understand this manual before handling.

・ Follow the additional document and/or direction, submitted by NOHKEN INC. and our distributor or agent, even if the terms are mentioned in this manual.

・ Save this manual in proper place being available to refer immediately. ・ The specification of product mentioned in this manual may not be satisfied by the

condition of environment and usage. Check and consider carefully before using. ・ Contact to sales office at NOHKEN INC. for any question or comment about this manual

and product.

The followings are the description of the terms in this manual.

DANGER Indicates a potentially hazardous situation which, if not pay attention, will result in death, serious injury or serious disaster.

WARNINGIndicates a potentially hazardous situation which, if not pay attention, could result in death, serious injury or serious disaster.

CAUTION Indicates a hazardous situation which, if not pay attention, may result in minor or moderate injury or damage to device.

Indicates prohibited matter. The explanation with this mark shall be followed

Indicates instructed matter. The explanation with this mark shall be followed.

－ADD 2 －

DANGER

Do not modify or disassemble the product. Otherwise, the flammable gas or vapor may be ignited.

DANGER

Do not open the terminal cover when powered. Leave terminal box more than 3 minutes to cool down after turn off the power. Otherwise, the flammable gas or vapor may be ignited.

WARNING

Install this product in hazardous location Zone 1 and 2, Do not install Zone 0.

Do not cause damage to the enclosure, joint surface, and thread on the cover. The explosion-protection of this product is retained by the strength of pressure for enclosure, wide and length of clearance.

Follow the description of inspection, adjustment, and maintenance in this manual, and not disassemble the parts except it is necessary. Otherwise, the explosion-protection of this product is not retained.

Ensure small screw for earth ground terminal, cover fixing bolt, and etc. Shall be tighten with spring washer. Otherwise, the explosion-protection of this product is not retained.

－ADD 3 －

WARNING

Adjustment, inspection, and maintenance for explosion-proof shall be done by the skilled person who has been educated and experienced.

Inspection and maintenance except visual check for this product shall be done where flammable gas or vapor is not occurred.

The electrical instrument for maintenance at hazardous location shall be approved as explosion-proof construction.

WARNING

Turn off the power immediately, if the smoke, strange smell and sound are occurred. Do not use it until the problem is solved.

Ensure the wire is properly connected. The product and connected device may be malfunctioned, damaged, fired, or miner injury and electric shock may be occurred by improper wiring.

Don't use the sensor which is made from resin, when the sensor measures materials with volume resistivity equal to or more than 109Ω・cm.

WARNING

Turn off the power immediately, if the smoke, strange smell and sound are occurred. Do not use it until the problem is solved.

－ADD 4 －

CAUTION

Recommend to use the earth terminal inside of the terminal box for grounding. The earth terminal at the surface of terminal box may be deteriorated by the environmental condition of usage.

The wire or cable for grounding shall be green color or stripe of green and yellow color (compliant with JIS). If not prepared, green color tape shall be installed at the tip of wire or cable to indicate for grounding.

CAUTION

Avoid shock and rough handling to this product. The product may be damaged by shock as dropping, falling, throwing, knocking, lugging, and etc.

Follow the specification of operating temperature, operating pressure, switch rating, and etc. Otherwise, the product and connected device may be malfunctioned, damaged, fired, or miner injury and electric shock may be occurred. Check the manual or specification sheet.

Operation test shall be done before practical usage. If the serious accident is expected to occur by malfunction of product, the other operating principle of product shall be installed in parallel.

In case of connecting inductive or lamp load to the product. Provide protective circuit to the load to avoid over voltage and over current. If not provide, the contact may be damaged.

－ADD 5 －

CAUTION

Do not grab and turn the terminal box, when the plug mounted product is removed from the tank. It may be cause of cutting internal wiring. The plug shall be loosened by the right tool.

Hold the stem very close to mounting point, when carrying, installing, and removing. If hold the terminal box, it may be taken off from the flange or plug, and the product may be damaged by dropping.

Check and deeply consider the chemical compatibility for material of product in advance. The part especially float, which is very thin, may be malfunctioned by miner corrosion.

CAUTION

Check and deeply consider the chemical compatibility for material of product in advance.

The product is 50cm or longer The product shall be kept in horizontally. The product and other goods be damaged, and miner injury may be occurred by falling.

The size of the cable inlet is G1/2”. There are two ways for connecting the sensor cable. One is fixing the cable with a cable gland. The other is connecting a conduit to the housing. In either case, an adequate sealing should be provided to prevent water or dust ingress into the housing through the sensor cable. Secure the cable using sealing material for the conduit connection, or a proper tool when the gland is used, to protect the housing inside from dust or water. When water or moisture comes into the housing from the conduit, use putty to fill the inside of the conduit.

－ADD 6 －

INTRODUCTION A) This manual specifies the specification of general product. If you order special product,

some details of specification may be different with the manual. B) We are glad to suggest and advice for Model selection and chemical resistant of

material, but final decision has to be made by the customer. C) This manual has prepared with close attention. Ask sales office at NOHKEN INC. for

any question or comment about the contents of this manual. D) For replacement parts The quality of product has frequently improved, so same spare part may not be

supplied. In this case, replacement part or product may be supplied. Ask sales office at NOHKEN INC. for details.

E) The contents of this manual are subject to change any time without notice due to the improvement of product.

WARRANTY & DISCLAIMER A) NOHKEN INC. warrants this product against defect in design, material and

workmanship for a period of 1(one) year from the date of original factory shipment. B) The warranty only covers the damage of products. The secondary and third kind

disasters are not covered by NOHKEN INC. C) NOHKEN INC. shall not be liable for the following.

C-a) Do not follow the description and direction in this manual. C-b) Damage due to improper installation, wiring, usage, maintenance, inspection,

storing, and etc. C-c) Repair and modification are done by the person who is not employee of NOHKEN

INC. C-d) Improper parts are used and replaced. C-e) The damage is occurred by the device or machine except our products. C-f) Improper usage. (See "Proper of usage" in chapter 1 in this manual) C-g) Force Majeure including, but not limited to, fire, earthquake, tsunami, lightning,

riots, revolution, war, radioactive pollution, acts of God, acts of government or governmental authorities, compliance with law, regulation, and order.

THE TERMS OF WARRANTY AND DISCLAIMER SHALL IN NO WAY LIMIT YOUR REGAL LIGHT.

ＴＡＢＬＥ ＯＦ ＣＯＮＴＥＮＴＳ Page No.

1. PURPOSE OF USE ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 1

2. DESCRIPTION ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 1

2.1 Description ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 1

2.2 Principle of operation ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 2

3. SPECIFICATIONS ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 3

3.1 Model numbering ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 3

3.2 Specifications ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 3

4. LOCATION ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5

4.1 Sensor ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5

4.2 Converter ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5

5. HANDLING NOTES ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 6

5.1 Handling Notes of explosion-proof for handling ‥‥‥‥‥‥‥‥‥‥‥‥‥ 6

5.2 Handling Notes ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 7

6. INSTALLATION ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 8

6.1 Sensor unpacking ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 8

6.2 Sensor installation ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 9

6.3 Converter unpacking ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥11

6.4 Converter installation ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥11

7. WIRING ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥12

7.1 Preparation ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥12

7.2 Cable inlet ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥12

7.3 Wiring ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥12

7.4 Covering ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥13

8. ADJUSTMENT ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥14

8.1 Nomenclature ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥14

8.2 Sensitivity adjustment ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥14

8.3 Initial adjustment ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥15

9. MAINTENANCE & INSPECTION ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥16

10. STORING ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥18

11. TROUBLESHOOTING ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥19

12. GLOSSARY ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥20

- 1 -

1. PURPOSE OF USE The CM is used for measuring liquids and chemicals continuously which the dielectric constants

is comparatively high. It is used for taking out the control signal from alarms or pumps.

Do not use in any other applications.

2. DESCRIPTIONS 2.1 Description

Model CM Capacitive Level Measurement is manufactured specifically for continuous level

measurement of liquids in containers at hazardous locations. The CM consists of a sensor

and an amplifier with co-axial cable. A variety of sensor specifications are available to

meet individual process conditions such as medium characteristics, installation conditions,

and so on. Due to no moving parts, the sensor deterioration is very small and the maintenance

is relatively easy.

Some types can be used for solids, granulars or interface between two immiscible liquids.

- 2 -

2.2 Principle of operation

The amplifier detection circuit for the CM is a impedance bridge circuit. The characteristics

of the balance of this bridge is [ L1・VC = L2・(C０+C) ]. The sensor and the metal tank

wall have a certain capacitance C in air. This capacitance C is one of the bridge circuit.

See Fig. 2-1.

When the sensor is in air, balance the bridge by adjusting VC and TUN.volume. Then, the

output voltage E０ will be 0V because there is no voltage between a and b. As the medium

displaces the air, an out-of-balance occures because of the differences in the capacitance

of the medium C and air. The output voltage E０ generates between c and d proportional

to changes in level (C).

The amplifier converts the proportional output voltage into a 4 to 20mA DC signal.

Fig.2-1

* See section 12 for the word explanation.

- 3 -

3. SPECIFICATIONS 3.1 Model numbering

The models on the nameplate are as follows:

3.1.1 SENSOR

ＣＭ－Ｂ

N : screw-in mounting

F : flange mounting

PN : screw-in mounting, with stilling tube

PF : flange mounting, with stilling tube

3.1.2 CONVERTER UNIT

ＣＭ－Ｐ１

A converter designed specially for CM-B.

3.2 Specifications

MODEL ＣＭ－Ｂ(SENSOR) ＣＭ－Ｐ１(CONVERTER)

MEASURING OBJECT Liquid

Accuracy ±3 % F.S. Measuring range 800 to 3900 mm

OPERATION

CHARACTERISTICS

Sensitivity 30 to 3000 pF F.S.

Power Supply - - - - -

100 V,200 V AC ±10 % 50/60 Hz(*1)

Power Consumption - - - - - Approx. 5 VA

Withstand Voltage

- - - - -

1500 V AC one minute

(Between power Terminal

and 'E' terminal)

Insulation

Resistance - - - - -

500 V DC more than 100 MΩ(Between power Terminal

and 'E' terminal)

Output Signal - - - - -

4 to 20 mA DC (Resistive

Load 500 Ω and under)

ELECTRICAL

CHARACTERISTICS

Wiring Inductance : 1 mH Max.

Capacitance : 0.1µF Max. MECHANICAL

CHARACTERISTICS

Withstand

Pressure 100 kPa Max. - - - - -

- 4 -

Explosion

Approval

Temperature

-10 to +40 (no dew condensation)

Working Humidity 85 % RH Max.

ENVIRONMENT

Working

Temperature

(Detection Part)

-40 to +130 - - - - -

Detection Part :Waterproof Construction (IP 68)

Housing(Sensor) :Drip-proof Construction (IP 65)

Housing(Converter): (IP 54)

CONSTRUCTION

Intrinsic safety TIIS certification i3nG5

Materials of

Housing

Aluminium Die Casting

(ADC12)

(Silver Hammertone

Coating)

Aluminium Casting (AC)

(Silver Hammertone

Coating)

Materials of

Detection Part

Electrode :

304 Stainless Steel

Insulator tube : PFA

- - - - -

Cable Inlet G 1/2 or equivalent 4×G1/2, G1/4

or equivalent

Recommendable

Cable

Co-axial cable RG62A/U

(Outside diameter :Approx.φ6.1 mm)

PHYSICAL

Separated Length 100 m Max.(Cable length)

* The senor coated with resin should not be used for measuring materials of volume resistivity

greater than 109Ω cm (electro conductivity smaller than 10-7) to prevent generating

electrostatics.

During maintenance or cleaning works, a wet cloth should be used to prevent generating and

charging electrostatics.

*1 The power supply can also manufacture the converter of 110 V,220 V AC 50/60 Hz and 120 V,

240 V AC 50/60 Hz.

- 5 -

4. LOCATION

4.1 Sensor

Install the sensor at the position where the medium level variations will actually make

contact with it. The sensor shall be installed vertical in the top of metal tank. Make sure

the electrode is not touching the nozzle, the stand-off pipe and the tank wall.

The CM mounting method varies depending on the connections you specified. Provide the

compatible nozzle or mating flange to be properly installed. In case of negative or positive

pressure within the tank, use suitable pipe compound or thread tape.

CM-BPN or CM-BPF is recommended for the none-metal tank or the presence of turbulence in

the tank. See Fig. 4-1 for dimensions of each models.

Fig.4-1

4.2 Converter

Dimensions and mounting pitch of the converter is shown below Fig. 4-2.

Fig.4-2

The cable inlet and the cover must be properly fitted to ensure airtightness and to protect

from dust, rain, splashing water, and so on.

- 6 -

5. HANDLING NOTES Since this product is approved as intrinsically-safe construction by combination of the sensor

and the converter, following shall be observed when handling. Otherwise, explosion with

flammable gas or vapor may occur.

5.1 Handling Notes of Explosion-proof

5.1.1 This product is approved by the combination of the sensor and the converter.

Thus, the sensor can be installed in hazardous locations (*) containing the gas

atmospheres which the CM is certified to be explosion-proof in.

However, the converter shall be installed in non-hazardous locations only.

Since it is indoor use, install in the drip-proof enclosure, more than IP54.

5.1.2 A co-axial cable (2.95/0.65TXE) should be used between the sensor and the converter.

Care must be taken not to damage the cable sheath.

5.1.3 Locate the power line or the signal line away when cabling between the sensor and the

converter. Do not lay with them when more than one unit is used.

5.1.4 For co-axial cable, the wiring inductance shall be 1.0 mH maximum, and capacitance

0.1 μF maximum.

5.1.5 The Intrinsically safe performance protective grounding terminal of the converter, JIS

Class A ground (max. ground resistance is 10Ω) shall always be provided in isolation.

Other grounding terminals (terminal symbol "GE") of the converter and the sensor, shall

be strictly grounded.

5.1.6 Do not open the panels or remodel the inside of the sensor or the converter.

5.1.7 The senor coated with resin should not be used for measuring materials of volume

resistivity greater than 109 Ωcm (electro conductivity smaller than 10-7) to prevent

generating electrostatics.

During maintenance or cleaning works, a wet cloth should be used to prevent generating

and charging electrostatics.

5.1.8 When cleaning or inspecting the sensor, wipe the detection part with the wetted cloth

to avoid electric shock.

Fig.5-1

- 7 -

5.2 Handling Notes

5.2.1 Avoid physical shock. Dropping, throwing or

bumping shall damage the sensor.

5.2.2 Do not put things on the sensor.

It shall deform and damage the sensor.

5.2.3 When painting the sensor, do not paint on the

nameplate to keep the indication of serial

number for future reference when ordering

parts.

5.2.4 Do not use or store in a corrosive atmosphere.

(NH3, SO2, Cｌ2, etc.)

Internal circuit shall be corroded and

conduction failure may occur.

5.2.5 Do not use or store where vibration occurs. If

inevitable, provide appropriate means to

prevent from vibration.

5.2.6 Locate away from the noise generator such as

motors, pump, inverter and so on or high

frequency electric field.

The sensor may cause malfunction.

Nameplate

P a inting

C o r r o s ive atmosphere

M o t o r s , p u m p s

V i b r a t i o n

Noise

- 8 -

6. INSTALLATION

CAUTION

This product is approved by the combination of the sensor and the converter.

Thus, the sensor can be installed in hazardous locations containing the gas

atmospheres which the CM is certified to be explosion-proof in. However, the

converter shall be installed in non-hazardous locations only.

6.1 Sensor unpacking

6.1.1 Take out the sensor from the package carefully.

Hold the hexagon part of the plug or flange.

6.1.2 If the sensor length is more than 1500mm,

handle the sensor with more than 2 people.

Otherwise, the sensor may be hit and the bent

of an electrode may cause malfunction.

6.1.3 Avoid physical shock. Dropping, throwing or

bumping shall damage the sensor.

6.1.4 Model numbering of the nameplate.

Check it to be sure as required.

6.1.5 Check the sensor exterior for damage.

If there is, contact Nohken.

6.1.6 Remove all wrapping materials such as tapes,

plastic bags, the carton protection etc.

After removing, inspect all components for

damage.

N a m e p l a t e

- 9 -

6.2 Sensor installation

6.2.1 Sensor location

Provide ample space for maintenance /

inspection. (At least the same length as the

sensor.)

Then, check the following. If not, the sensor

may cause malfunction.

(1) Do not install near liquid inlets/outlets, near

agitator and/or the direct flow.

Provide the metallic stilling tube (*)if

necessary. The internal diameter of this

stilling tube shall be more than φ40mm.

Make sure the it is electrically connected with

the sensor installation part and the

container.

Provide a vent hole above the Max. level.

If not, liquid level may have differential

between in and out of the tube. If there is

no holes, liquid level can not increase in a

pressurized tube.

(2) Make sure there is no obstruction such as pipes

near an electrode.

Provide the metallic stilling tube if

necessary.

* See section 12 for the word explanation.

Space

Co n t a i n e r

S e n s o r

- 10 -

(3) Max. temperature range for electrode is +60

and +40 for the housing. Do not install where

exceeds the temperature range.

(4) Do not locate the sensor where exposed to

direct sunlight. Install a sun shield over

the housing if necessary.

(5) Do not use or store in a corrosive atmosphere

such as NH3, SO2, Cl2, etc.

Internal circuit shall be corroded and damage

the sensor.

(6) Locate away from splashing water. The housing

protection is IP65. Tighten the housing cover

and the cable entry to prevent water from

intruding.

6.2.2 Installation

<plug mounting>

Tighten the sensor securely. The wrench or the other appropriate tool is applied only

to the hexagon part of the plug. Do not turn the housing.

The screw part and the container shall be electrically connected when sealing.

CAUTION

Wrench the plug when installing. Do not turn the housing. Otherwise the housing

connection to the plug will be broken.

<Flange mounting>

The CM requires gasket, bolts and fittings for installation. Provide the compatible

mating flange on tank top. Install the sensor with a suitable gasket and conforming

bolts by using appropriate tool.

Sun S u n s h i e ld

C o r r o s i v e atmosphere

Plug

H ousing

- 11 -

(1) When installing on the metallic container,

make sure the plug or flange and the container

is electrically conductive.

(2) When installing the sensor to non-metallic

container, the metallic reference probe shall

be installed parallel to the sensor electrode

and is connected to the sensor plug or flange.

The length of metallic reference probe must be

longer than the sensor electrode. Make sure

that the sensor plug or flange and the metallic

reference probe are grounded. (Grounding

resistance is 100Ω Max.)

6.3 Converter unpacking

Take out the converter from the package carefully and avoid physical shock.

Dropping, throwing or bumping shall damage the converter.

6.4 Converter location

When installing the converter, provide ample space for maintenance/inspection. Then, check

the following. If not, the converter may cause malfunction.

(1) The converter shall be used under the following conditions:

Ambient temperature ; -10 to +40

Relative humidity ; 85% Rh Max. (No dewing)

(2) The mass of the converter is approx. 1.3kg. Provide appropriate reinforcement for thin

panel if necessary.

(3) Locate away from splashing water. The converter is not a spray-proof construction.

N o n - m e t a l l i cMetallic

Elect r i c a l l y

(Groundingresistance is

condu c t i v e

100 Ω Max.)

Met a l l i c r e f e r e n c e probe

c o n t a i n e r c o n t a i n e r

- 12 -

7. WIRING

7.1 Preparation

7.1.1 Turn off the power supply.

WARNING

To avoid personal injury, leakage current or short circuit, the power supply

shall be always turned off while wiring.

7.1.2 Remove the housing cover.

7.2 Cable inlet

The size of the cable inlet is G1/2.

There are two ways for connecting the sensor cable. One is fixing the cable with a cable

gland. The other is connecting a conduit to the housing. In either case, an adequate sealing

should be provided to prevent water or dust ingress into the housing through the sensor

cable.

Secure the cable using sealing material for the conduit connection, or a proper tool when

the gland is used, to protect the housing inside from dust or water.

When water or moisture comes into the housing from the conduit, use putty to fill the inside

of the conduit.

Fig.7-1

7.3 Wiring

CAUTION

The Intrinsically safe performance protective grounding terminal of the

converter, JIS Class A ground (max. ground resistance is 10Ω) shall always be provided in isolation. Other grounding terminals (terminal symbol "EG") of the

converter and the sensor, JIS Class D ground (max. ground resistance is 100Ω) or higher shall always be provided.

Otherwise, personal injury or short-circuit may be occur.

7.3.1 Power supply is 100V AC or 200V AC. In case of 100V AC, connect to terminal 0-100V.

If 200V AC, connect to terminal 0-200V. Check for miswiring. Otherwise, the sensor

shall be damaged and/or there is a danger of ignition.

- 13 -

Fig.7-2

7.3.2 Use the attached co-axial cable between the sensor and the converter.

This cable must be run in conduit and be grounded. Avoid to cut and/or extend the cables.

Otherwise, you must adjust the CM by yourself in accordance with section 9, ADJUSTMENT.

7.3.3 Do not lay the power cable or the magnet switch cable in parallel.

7.3.4 Separation distance between the sensor and the converter should be 100m Max.

For co-axial cable, the wiring inductance shall be 1.0 mH maximum, and capacitance 0.1

µF maximum.

7.3.5 Resistive load of the 4 to 20mA DC output is Max. 500Ω. If exceeds, the converter may cause signal errors and/or malfunction.

If you are not connecting the load, connect the jumper wire between + and -. Otherwise,

the liquid and/or powder level indication will not operate.

7.3.6 Wire the sensor terminals and the converter terminals.

Use appropriate tools when fixing screws.

Terminal screw of sensor is M3.0. Solderless lugs in R1.25-3 are recommended.

Terminal screw of converter is M3.5. Solderless lugs in R1.25-3.5 are recommended

7.4 Covering

Make sure that there is no dust for metallic substances in the housing. The housing cover

shall be tightened to protect from rain, splashing water, dust and so on.

- 14 -

8. ADJUSTMENT

8.1 Nomenclature

Fig.8-1

① TUNE-1 : Initial tuning volume

② TUNE-2 : Initial tuning volume

③ SPAN VR : Span adjustment volume for output current (Rough tuning)

④ SW : Switch for compensation of sensor capacitance

⑤ TP-1 : Check terminal for initial tuning

⑥ ZERO VR : Zero volume for initial tuning

⑦ GAIN VR : Volume for sensitivity adjustment

⑧ TP-2 : Check terminal for output current

⑨ SPAN VR : Span adjustment volume for output current (Fine tuning)

⑩ ZERO VR : Zero adjustment volume for output current

8.2 Sensitivity adjustment

Initial tuning in the air is calibrated at the factory. Generally, only the sensitivity

needs to be adjusted.

WARNING

For hazardous areas, extra precaution must be taken during adjustment.

Before the housing cover is removed, power must be turned off.

CAUTION

Do not touch any volume which is not specified on this manual.

Otherwise, the CM may cause malfunction.

- 15 -

8.3 Initial adjustment

Readjust initial tuning as follows when:

・ sensitivity setting can not adjust.

・ the sensitivity range is changed.

・ the probe length is changed.

・ the measuring medium is changed.

8.3.1 Check for no miswiring.

8.3.2 Make sure the CM is not contacting measuring medium or the container. Keep the measuring

medium lower at least 5cm from the tip of the sensor.

8.3.3 Turn on the power and connect the voltmeter ＋ to red TP-1 (⑤) and the voltmeter －

to the black. Set voltmeter range to 1 to 10V DC in accordance with the voltage.

8.3.4 Turn the SPAN VR (③) to clockwise from the center.

8.3.5 Turn both of the TUNE-1 volume (①) to fully counterclockwise.

8.3.6 While turning either of the TUNE-1 volume (①) to clockwise, the voltage will once become

low and then become high again.

Set TUNE-1 volume (①) to the lowest voltage.

If the voltage did not become high despite turning the TUNE-1 volume (①) to fully

clockwise, use another TUNE-1 volume (①) and set to the lowest voltage.

If both TUNE-1 volume (①) did not work, switch SW (④) one step higher (for example

from 50 to 100) and repeat steps 7.3.5 and 7.3.6 to set to the lowest voltage.

8.3.7 Still, the voltage will go up and down if you turn the TUNE-2 VR (②). Again, set to

the lowest voltage.

8.3.8 Adjust the voltage to 0V DC with the ZERO VR (⑥).

8.3.9 Set the voltmeter range to detect 4 to 20mA DC. Connect the voltmeter ＋ to red TP-2

(⑧) and the voltmeter － to the black.

8.3.10 If indication meter is not connected to the output terminal M+ and M-, shorten between

them.

8.3.11 Adjust output current to 4mA DC with the ZERO VR (⑩).

8.3.12 Put measuring medium into the container until it reaches to the level where you wish

to indicate 100%.

8.3.13 Adjust output current to 20mA DC with the SPAN VR (③ and ⑨).

(Rough tuning with SPAN VR (③) and fine tuning with SPAN VR ⑨).)

8.3.14 If 20mA DC can not be adjusted with SPAN VR (③ and ⑨), adjust with GAIN VR (⑦).

Turning GAIN VR (⑦) to clockwise increases the current.

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9. MAINTENANCE & INSPECTION Remove the sensor from the tank before maintenance. See section 5. Keep the ample space for

maintenance.

9.1 Removing

9.1.1 Turn off the power supply.

WARNING

To avoid personal injury, the power supply shall be always turned off while

wiring.

9.1.2 Remove the housing cover. Disconnect all wires and the flexible conduit.

CAUTION

Wrench the plug when installing. Do not turn the housing. Otherwise the

housing connection to the plug will be broken.

9.1.3 Unscrew the fixing bolts or loosen the plug and remove the sensor carefully from the

tank.

9.1.4 Put the sensor on the flat and ample space.

Plug

Housing

- 17 -

9.2 Maintenance & inspection

Inspect the sensor semi-annually or annually. Since inspection intervals varies with

applications and process conditions such as pressure, temperature and so on, we recommend

you to inspect periodically.

9.2.1 Check for and replace damaged/collapsed parts.

9.2.2 Clean contaminant or sticky material.

9.2.3 Clean dirt, dust and moisture from housing.

9.3 RE-INSTALLATION

See 6.2, Sensor installation.

9.4 Wiring

See 7, WIRING.

9.5 Replacement parts & cycle

Replace to our special-purpose parts if the following symptoms occur.

The life expectancy of the CM may be 5 years due to the deterioration of electric parts

or corrosion of the insulation tube.

9.6 Replacement parts list

Parts Name Replacement Cycle

Housing

P.C. board

Insulation tube

When it is damaged or corroded.

9.7 Adjustment

See 8, ADJUSTMENT.

RemoveDust or metallic

substances

- 18 -

10. STORING The sensor shall be stored under the following conditions when it is not used for a long time:

10.1 Environmental conditions are as follows:

・ The storing temperature range is -10 to +60.

・ Relative humidity is 85% Max.

・ No corrosive gases (such as NH3, SO2, Cl2, etc.).

・ Locate away from condensation, dust and foreign matters.

・ Vibration is low.

10.2 Keep the sensor out of rain, splashing water.

The cable entry shall be pointing down to the

ground.

10.3 Put the cover on the housing and the blind lid

on the cable gland.

Otherwise, the dust will intrude into the

housing. For precaution, the cable entry shall

be pointing down to the ground.

10.4 Clean deposit or sticky material build-up on the

electrode. Otherwise, the operation will be

affected after solidifying.

10.5 Deposit the sensor on the appropriate seating

such as wood.

Otherwise, the sensor rolls, electrode will be

bent and damage an insulation tube. Especially

for the sensor with more than 2000mm electrode,

bear each 1000mm to prevent from bending.

10.6 Do not put things on the sensor.

It shall damage the electrode.

Reference

Keep the sensor in sealed plastic bags with desiccant or other moisture-proof packing.

- 19 -

11. TROUBLESHOOTING

CAUTION

Use the following chart to troubleshoot the malfunctioning sensor.

If your remedies are unsuccessful, ask Nohken for repair and replacement.

11.1 Output signal can not increase

Possible causes Remedies

Miswiring. Wire correctly.

Medium has an angle of repose. Install the probe in good location.

Initial tuning failure. Readjust the initial tuning.

Power supply too low. Use specified power supply.

Dielectric constant of the medium changed. Reselect the sensitivity range.

Foreign matters and/or water penetrated

inside the probe and a converter.

Remove the foreign matters and check the

resistance between the probe and the

housing. (Return the sensor to replace

damaged parts if you can not read ∞.)

11.2 Output signal can not decrease

Possible causes Remedies

Miswiring. Wire correctly.

Medium has deadstock. Install the probe in good location.

Heavy build-up on an electrode. Clean an electrode.

Initial tuning failure. Readjust the initial tuning.

Dielectric constant of the medium changed. Reselect the sensitivity range.

Foreign matters and/or water penetrated

inside the probe and a converter.

Remove the foreign matters and check the

resistance between the probe and the

housing. (Return the sensor to replace

damaged parts if you can not read ∞.)

Electrode is in contact with the tank wall

or the angle.

Locate an electrode more than 100mm or

provide supports to avoid contacting.

- 20 -

12. GLOSSARY General words and phrases

Condenser Involves two electrode which has capacity.

Capacitance When positive and negative electric charge Q is supplied between

two metallic electrodes, and the potential is V, it can be shown

as C=Q/V.

Conductivity The ease of the flow of electricity through substances.

Stilling tube A depression in a container enough to reduce turbulence or flow

of the liquid.

Plug A part to secure the sensor on the container by screw.

Flange The flat edge parts to install the sensor in the container by

using bolts and nuts.

Stray capacity Initial capacity formed between an electrode and the container.

Words and phrases about Explosion-proof

Hazardous Area Areas in which dangerous concentrations of flammable

gases/vapors are present or the chances are high. In such areas,

explosion protection should be implemented on electrical

devices.

Zone 0 Areas in which dangerous concentrations of flammable

gases/vapors are present continuously or long-term under normal

operating conditions.

Zone 1 Areas in which dangerous concentrations of flammable

gases/vapors are present occasionally under normal operating

conditions.

Zone 2 Areas in which dangerous concentrations of flammable

gases/vapors are present rarely and then only briefly under

normal operating conditions.

HEAD OFFICE : 15-29,Hiroshiba-cho,Suita-city,Osaka 564-0052,Japan.

TEL:06-6386-8141 FAX:06-6386-8140

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TEL:03-5835-3311 FAX:03-5835-3316

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TEL:052-731-5751 FAX:052-731-5780

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