1

Saturday Sept 16, 2006

Update on hardware11:55 – 12:15

V81M (not V81T)

• 50% reduction in power. -lower bearing temperature.

• Slightly higher pump speed.• Higher tolerance to forelinepressure.

All future AMS systems will use the V81

Varian V81M released July 2006A replacement for the V70LP

2

Comparison of pumping speed for V70LP and V81M

51.20287.13x10-3V 81-MAr

46.56177.84x10-3V 81-M

37.60299.71x10-3V70LP

He

52.45236.98x10-3V 81-M-80k

48.55227.52x10-3V 81-M-75k

48.55457.52x10-3V70LP – 75k

N2

S (L/s)Power (W)

Pin (mbar)

Pump

Data from Varian

V81M Upgrade IssuesVarian has an upgrade program to exchange a V70LP for

a new V81M.New V70LP pumps are no longer available but

rebuild/exchanges are still supported.Electrical and roughing port are the same style and

location as V70LP.V81 does require a new cooling fan mounting bracket.The V81 PCB controller has the same electrical

connections and mounting holes as the V70 PCB controller.

The V70 PCB controller WILL drive the V81M pump at slightly reduced speed (75 KRPM vs 80 KRPM).

3

V 81-M: Compression ratio

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+10

1.00E-01 1.00E+00 1.00E+01 1.00E+02

Foreline pressure (mbar)

Com

pres

sion

ratio

Ar N2 N2-75 He

Operating with V70 controller will slightly reduce best performance

75 KRPM

80 KRPM

Data from Varian

New Pump Controller Interface

Improved control and diagnostics of the vacuum pump system

• Diaphragm pump• Turbo Pumps• Total DC current consumption• Inlet pressure (auto start)• PC control through USB with data logging capability• Older systems are upgradeable

4

G1 aircraft cTOF with new pump control system

Controller has a 4x20 character LCD with a 3-fxn data entry knob and a USB port for PC control.

Successfully operated on G1 aircraft in MaxMex 2006

Turbo Pump Status and Error Messages

Pump ErrorsNo connectionPump over tempController over tempPower failNormal start failSoft start failShort circuitToo high load

Pumps StatusStoppedInterlockStartingAuto TuneBrakingNormalError

Pump status, pump speed, bearing temperature (and controller), and current are continuously updated.

5

PC Software interface for Pump Controller

20

10Box

T(C

)

11:00 AM1/19/2006

12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM

Date/Time

10

TotA

mps

2

0

P(to

rr)

6.00

MD

1Spd

BoxTemp TotalAmps Baratron MD1Speed

PumpStats_Jan19.pxp

35

30

25

20

15

10

Pum

p Te

mp

(C)

11:00 AM1/19/2006

12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM

Date/Time

P2 V301 P3 V70 P4 V70 P5 V301 P6 V70

PumpStats_Jan19.pxp

1400

1200

1000

800

600

400

200

0

Pum

p C

urre

nt (m

A)

11:00 AM1/19/2006

12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM

Date/Time

Pump Current P2 V301 P3 V70 P4 V70 P5 V301 P6 V70

PumpStats_Jan19.pxp

C:\DATA PARTY\FieldWork\G1_Veracruz06\G1TestFlight_Pasco06

Pump 3 runs warmest

Pump 3 has highest failure rate…

Diagnostic plots

6

Consider Water Cooling Turbos in Warmer Operating Environments

• Since we now know that P2 (V301) and P3 (V70) run warmest water cooling these may be beneficial.

• Water cooling all turbos is probably not necessary.

1400

1200

1000

800

600

400

200

0

Pum

p C

urre

nt (m

A)

10:40 AM1/19/2006

10:42 AM 10:44 AM 10:46 AM 10:48 AM 10:50 AM

Date/Time

Pump Current P2 V301 P3 V70 P4 V70 P5 V301 P6 V70

PumpStats_Jan19.pxp

220

210

200

190

180

170

Pum

p C

urre

nt (m

A)

10:30 AM1/19/2006

11:00 AM 11:30 AM 12:00 PM 12:30 PM

Date/Time

Pump Current P2 V301 P3 V70 P4 V70 P5 V301 P6 V70

Vaporizer on

Fil ON

PumpStats_Jan19.pxp

Startup behavior

P5 load increases when filaments are turned on

7

Electronics needs to be redesigned for TOF systems

Only chopper, vaporizer and heater bias are need for TOF

Power supply can be redesigned for TOF system

24 VDC supply (40A) in a 1U RM size

8

Constant Pressure Inlet System

• Important for use on aircraft. • Eliminates variation of particle velocity and

particle transmission calibration as lens pressure changes with altitude.

• Past and current efforts have been made by – Ann Middlebrook (P3)– Jose Jimenez (C-130/HIAPER)– Jonny Crosier (BA 146)– J. Jayne (G1)

Compact pressure controller system

Houses small pump, electronic valve and PID controller

9

Calculated Pressure Altitude relationship

G1 Max. altitude 17,000 ft ~420 torr (for MaxMex)HIAPER max. altitude 51,000 ft

60x103

50

40

30

20

10

0

Altit

ude,

ft

100 2x102 3 4 5 6 7

Pressure, torr

HIAPER_maxAlt MexCity_Alt_ft G1_alt

SeaTacFlightMex2006.pxp

P2

Proportional Solenoid / PID

control

P1

Standard Lens

400 torr ~= 17K ft

Regulate P1 to 1.3 torr

Feb 4, 2006

130 um SPI#8 Okeefe

For Plens=1.28 torr (controller set point), P2 =420 torr.

Okeefe #8. 353 cc/m measured under choke flow conditions

Schematic of test setup to evaluate pinhole sizes, pressures and flows

Flow measurement

Needle valve to simulate altitude

P3

KNF UNMP50 pump

Controller acts on lens pressure

10

Evaluation of pressure regulation range

I choose the green points, Okeefe #8…

1.8

1.6

1.4

1.2

1.0

0.8

0.6

P le

ns (t

orr)

800700600500400300200

P ambient (torr)

400

300

200

100

0

Flow

(cc/

min

)

130 um, Set point=1.260 Plens_b #10 Okeefe Plens_c #5 Okeefe Plens_d #8 Okeefe. Plens_e #16 Okeefe Flow_d #8 Okeefe

Aerosol transmission tests were performed using this plumbing arrangement.

QAMS, standard lens, 215 series chamber.

From DMA/dilution system

.008” Okeefe

130 um SPI

11

1000

800

600

400

200

0

AMS

(#/c

c)

10008006004002000

CPC (#/cc)

Dmob NH4NO3 (1.41 torr lens, 130um SPI) ams_300nm ams_350nm ams_400nm ams_250nm ams_200nm 1:1 line

unkown Okeefe measure 353 cc/m = #8 (.008")

Collection efficiency measured by direct count method.

Used QAMS standard lens, 215 series chamber, Pressure Controlled inlet, Plens=1.41 torr.

60

50

40

30

20

10

0

Sig_

p46

Avg

4 5 6 7 8 9100

2 3 4 5 6 7 8 91000

2

Dva

Standard 100 um pinhole Sig_p46_R231_R230_avg

Press Controlled Okeefe Hi Sig_p46_R234_R235_Avg

Press Controlled Okeefe Low Sig_p46_R228_R233

50

40

30

20

10

0

Sig_

p46

Avg

2 3 4 5 6 7 8 9100

2 3 4 5 6 7 8 91000

2

Dva

50

40

30

20

10

0

60

50

40

30

20

10

0

Standard 100 um pinhole Sig_p46_R231_R230_avg

Press Controlled Okeefe Hi Sig_p46_R234_R235_Avg

Press Controlled Okeefe Low Sig_p46_R228_R233

Polydisperse NH4NO3 sampled by 3 different configurations:

1) Standard 100um pinhole assembly

2) 130 um pinhole with Okeefe ¼” tube orifice at upstream end (high)

3) 130 um pinhole with Okeefe ¼” tube orifice at downstream end

The two plots are the same data, one has normalized Y-axis

Collection efficiency.

Measurement of polydisperrse NH4NO3 using standard 100um pin-hole assembly and pressure controlled inlet. Aerosol concentration kept ~constant at (3.5-4.0)e4/cc.

This figure suggests that there are no significant losses in PC inlet.

12

Pressure Controller Summary• Determine lowest pressure range for

operation…select pinholes and pump.• Use the lens pressure as the pressure to

regulate. – Eliminates a second pressure gauge

• For sampling pressures >~400 torr losses seem to be small.

• For sampling pressures <~400 torr losses may be significant. Need to design better sampling interface to minimize losses.

• Application: tunable pressure lens

Direct Probe GC Inlet

• Designed for Dr. Akiama at Japanese Automobile Research Institute (JARI)

• Allows use of TOF spectrometer to measure effulents from GC capilarycolumn

13

Copper-Stainless steel braze jointThermal isolation

Cartridge heaters inserted in this blockSt. St 3/4OD tube for thermal isolation

Teflon ferrule used here

24 gauge (.016” ID x .022” OD) st. st. capillary tube extends from GC column connector thru the entire length of the copper rod, makes a 90 degree bend upwards to direct fused silica column effluent to ionizer.The silica column is inserted into the st. st. column which provides ease of assembly, alignment and (good?) thermal contact with the heated copper pieces.

GC column connector

St. st. capillary column extends to the face of this connector

14

Two step insertion process.Insert probe from the rear with vertical copper piece removed.Vertical copper rod is installed after inserting probe. Note steel capillary tube is bent horizontal for insertion from rear of AMS.

Vertical copper rod is installed from top of chamber, access thru VUV port is helpful. Note steel capillary tube is now vertical, directing gas to ionizer.

Thermocouple location for temperature regulation

Stainless Steel capillary24 gauge. .016” ID x .022 OD (hard to see in photo)

Make No contact between copper rod and Al. cylinder…

15

Slide GC column inside of steel capillary column until it won’t go any further…this is where the st. st. column bends 90 deg. Upward into ionizer. Hand tightened brass nut with vespel ferrule for a leak tight seal.

I used an RGA on detection chamber to test for leaks as the system was heated

Flow measures 17.6 cc/min at entrance end of column.V301 at 0.88 amps…ok (0.34 amps no load)

16

Heating scheme. Two cartridge heaters (3/16 OD x 1.5 L 20 W 120 VAC ) inserted into copper block. With insulation, achieved 180C. Need a bit more power will get new higher power heaters. No leaks…

These 20W heaters have been replaced with two 100W ¼” OD heaters….plenty of power

¾ OD St.St. tube thermally isolates from chamber.

PID controller

Nov. 29, 2005

100W heaters tested…max temperature tested was 250C.

Measuring of temperature gradient between heater block and probe temperature.

For temperatures >200C you may need to cool the ¾” St. St. tube with either a heat sink or a small fan.

17

Minimal temperature losses

300

250

200

150

100

50

tem

p (C

)

1614121086420

point number (~time)

T_Probe T_Block

Controller Set Point = 100

This shows that there is essentially no temperature gradient between the heater block and the probe temperature, ie no heat losses. Initial set pt was 100C. Changed to 250, which also equilibrated (but not shown). Note large overshot on heating block...the PID algorithm needs to be tunned (see Newport controller manual for proceedure).

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m 152

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m 166

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m178

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m228

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m252

0

0.01

0 10 20 30 40 50Retention time (min)

Response

m276

(a) Acenaphthylene

(b) Fluorene

(c) Phenanthlene

(d) Chrysene

(e) B[a]P

(f)B[g,h,i]P

Dr. Akiama’s Direct Probe results with VUV photo ionization