IFR Gas Mixer Information
Contact: Doug Wright, email@example.com
Gas Analysis Results
Trip point settings
Isobutane release limit
Isobutane bottle change procedure
|Gas||Regulator settings ||Typical usage rates
||Grade (Supplier is Air Gas)
|Argon ||32-40 psig || One six-pack per 3 days |
(40.3 lbs per day)
| $85/six-pack |
|Isobutane ||30-34 psig|| One bottle per 28 days |
(4.2 lbs per day)
| $450/bottle || 99.5% by weight in liquid phase |
|Freon ||32-40 psig|| One 1000lb tank per 14 days |
| $3500/tank || (no purity spec)
Backup = three full and one partial 120lb bottles
1 atmosphere = 1 bar
1 bar = 14.5 psi
= 750.06mm Hg = 750.06 torr (1mm Hg =1torr)
= 29.53 " Hg
= 401.47 " H20
= .01 kPa
Cole Parmer Unit Pressure Conversions
sccm = cc/minute at 0° C and 1 atmosphere
- Get adjustable power supply and recalibrate flow meters
- Change flow controller gain factor to match meters (once calibrated)
- Removed flow controllers from panel to reset decimal point (do spare
as a test)
- Replace pneumatic relay that leaks (last one on south side, controls fill valve)
- Calibrate EPICs panels for flow (after calibrating hardware)
- Argon. Check the gauges on the output-side of the regulators to
determine which gauge is correct (there is a 4psi difference between
the two gauges). Replace the bad gauge(s).
- Fix house air connection to spare line (running through
- Tighten/replace compressed air actuator (south-most)
9-25-03. 6:10am. Input flow fault and fill operation fault. Reseting
the system solved the prolbem.
7:30am. Happened again. Shifter reset.
8:15am. Happened again (input flow fault), shifter paged me. Reset and ok. No indications of
Manifold pressure 40psi
Primary 42psi 46psi bottle
Second. 44 56
Cyl #1 temp 88 F
9-23-03. 5:30am. Output flow fault. Shifter pushed reset button, but
did not do SIAMs. It appeared that the system completed a fill cycle even
though the isobutane was shutoff. Talked shifter through reset process.
Fill proceded normally.
9:00pm. Input flow fault. Happened while cryotech in gas shack (according
to shifter). No apparent cause, shifter reset and ok. Both argon
sixpacks were full, perhaps this was caused by argon six-pack change?
9-12-03. 10pm. All faults tripped when IR2 switched back from
emergency to site power (part of recovery from site power failure
earlier in the day). Many other systems were tripped. Siam crate
power was off. Isobutane shutoff valves could not be reset because
DCH isobutane had a problem. DCH experts had to clear DCH problem
9-12-3. 8am. New problem. Isobutane flow controller extremely
erratic. Caused fault when isobutane flow monitor exceeded upper
limit (monitor was no longer dead). Suspected liquid in flow
controller. Fix was to put on infinite vent and reduce regulator pressure
in gas shack to 30 psi. After about 30 minutes, both the flow
controller and flow monitor recovered. Had to completely close
the regulator to get the pressure to drop. Then reopened the
9-11-03. 8pm. More input flow faults, but not due to isobutane
pressure. Ultimately traced it to sudden and spurious drop in
isobutane flow monitor. Eventually the meter died completely! Set
lower trip limit to -9 to avoid trips until gauge/meter can be
Input flow fault at 2am. Due to low isobutane
pressure. Primary bottle ran out, but secondary bottle was only 24 psi
(contrary to test during the day where it was 30 psi). Switching this
bottle to the primary regulator (set at 40psi) was still insufficient
to complete a fill. The pressure dropped below 12psi. Note, at 12 psi
the flow controller began to lose flow. Solution, set interior
regulator to maximum and raise primary regulator to 43 psi (measured
during fill), which reads 42 psi on manifold gauge.
Also replaced isobutane cylinder#1 old=75lbs, new=191 lbs. Restored
rubber pad under cylinder #1. Cylinder temperature was 59 Fahrenheit
at 5am. Took gas sample (bottle #1).
9-3-03. Tested effect of removing control cable on the output flow
monitor. It indeed causes a trip, but only mixed gas output flow
fault. It does not cause any other faults, even if the system is
filling. Note that engaging the output fault override prevents the fault
Calibrated output gas monitor. Signal is pin#2, signal ground pin #11.
Set full scale (5V) using external power supply. Set gas calibration
constation of 0.652. The output flow reads 12.6 l/min actual.
Isobutane cylinder gas lines were swapped! Probably done by techs when
they disconnected/reconnected us for work on the DCH gas system.
Weighed both cylinders. Cylinder #1 was 113 lbs, #2 was 114 lbs, tare
weight is 68 lbs. Replaced cylinder #2 with new bottle
(189lbs). Raised primary regulator pressure to 36 psi, raised
secondary to 29 lbs. Set regulator on gas mixer to 26 psi.
9-1-03. Steve Faulkes noted that control cable to new output flow
meter (mixed flow monitor gas 5) was loose. Tightened connector.
8-28-03. 7pm. Input flow fault. Reset and ok. No obvious reason for
8-21-03. Gas system mods completed. System restarted. Switch to mixed
gas in IR2. Flow controller settings:
argon isobutane freon
old 715 273 902
new 715 546 902
Also changed vent duration from 15 to 20 seconds. Changed input flow
(high and low) limits on flow meters to match expected flows.
Expect new flow rate to be 11 l/min actual. With gas flowing,
fill time (1500->1600 torr) is 14 minutes. Drain time (1600->1500) is
8-20-03. Matt Neibel & Steve Foulkes started on replacing gas system
parts to increase flow rate. New 20 slm on freon line. Old 10 slm
moved from freon to argon line. Old 5 slm removed from argone
line. New 100 slm meter on mixed gas output. Old 10 slm meter
removed. Still waiting for pneumatic valve for mixed flow output
7-25-03. Gas inventory. Isobutane both tanks installed 6-19-03. Two
full tanks in rack. Freon. Two full tanks, online noticably light,
standby probably full. Argon, Three sixpacks installed 7-25-03 (tanks
1,2,3 = 1500,1500, 1700 psi). One full six-pack in reserve.
7-22-03. Tightened last two units of pneumatic valve block in gas
mixer. This stopped the loud hissing, leak. Removed Sierra Flo-box from
mixer rack. Put in bottom drawer of black filing cabinet in gas shack.
6-27-03 Took gas sample. Adjusted isobutane regulators. Freon tank arrived.
bottle temp 110 100 degree Fahrenheit
bottle press. 60 83 psi
reg. press. set 30 26 psi, set using vent
reg. press. flowing 28 2? psi
manifold press. 27 psi
inside regulator 24 psi
mixer press. 23.0 psi
6-19-03 Paged at 4:30 am for gas alarm. Low isobutane pressure, but
secondary regulator showed 32 psi on cylinder #2. Came to SLAC. Gauge
is bad, it reads 12.5 psi too high. Both isobutane bottles were
empty. Replaced isobutane cylinders #1 and #2. New bottles were
temp=55F which gives on 22 psi. Could not start mixer because of low
pressure fault. Lowered trip point on pressure monitor 3 from 15 to
12. With both bottles online, this allowed system to mix gas. At the
beginning of the cycle the isobutane flow controller set the gas to
7.00 before settling down to 1.33 (the proper setting). This caused
the input pressure line to drop below the old trip point of 15
psi. Other strange behavior is that the large manifold pressure gauge
on the isobutane supply outside, did not indicate the pressure drop
during the mix cycle.
Asked Mike Racine to two bottles of isobutane and check why freon
tank has not been replaced. Racine replies that bottle ordred yesterday,
should arrive 6-23-03.
5-29-03 Freon tank empty, ordered new one according to Mike Racine.
5-21-03 Requested order new isobutane cylinder to Mike Racine.
5-12-03 Isobutane cylinder#2 replaced.
5-9-03 Freon tank arrived (ordered 5-2-03).
5-2-03 M. Racine reports that freon tank ordered 4-14-03 arrived
by 4-18-03 and he has retrained the tech on duty (with regard to the
freon tank). A new tank should have been ordered today.
5-01-03 D. Wright noticed freon tank #1 (online) was empty. Emailed
4-14-03 Freon tank empty, swapped out. Mike Racine ordered new freon tank.
4-3-03 ~3pm. Premix bottle 16 psi.
4-2-03 3:15pm Premix online bottle 27 psi, regulator set 5 psi. (Simani)
Standby bottle is off.
3-29-03 Input fault. Reset and now ok. No reason for fault.
3-24-03 Isobutane arrived.
3-20-03 Requests to Mike Racine:
Lester the cryotech came by and said the flex line and new guages
will be installed tomorrow (Friday).
- Order two isobutane bottles
- Repair/replace kinked braided flex line on freon tank #2
- Replace input gauges on premix regulators so we can read 100psi.
Current gauges have too large of a range.
measured the fill rate using online monitor of Epics. Fills for 5.5
hours, coasts for 0.5 hours. So ~10% remaining capacity.
- Mike Racine reports premix gas panel finished and installed.
- Freon tank arrived (ordered 3-13-03!).
3-13-03 Mike Racine reports ordering new freon tank.
3-12-03 Input fault trip alarms due to freon pressure being low. Online
bottle ran out, but the standby bottles was valved off at the tank. Cryotechs
did not follow procedures! Called Mike Racine and requested techs fix
the situation. Wes came down and corrected valve settings, but did not
order freon or move tanks or belly band (end of the shift).
3-5-03 Pigtail for spare 120lb freon tank installed.
3-3-03 Put new isobutane bottle online. Cylinder #2 old 78lbs,
new 195 lbs. New freon tank arrived.
2-24-03 Mike Racine new freon tank ordered.
2-19-03 Met with Mike Racine and Matt for premix plumbing design:
- Install unistrut for two premix bottles on outside of gas shack wall
- Install gas line from outside to extra spare line in gas shack. Existing
spare line to remain intact (connected to gas mixer spare/argon line)
- Order two regulators and build panel for switching primary/secondary
regulators between cylinders
- Also requested new pigtail for 120lb freon cylinder.
1-28-03 Called Mike Racine. Asked for two new isobutane bottles
(only one was delivered on 1-21-03), and informed him of strange
checklist entry for 1-26-03. Mike later reported that the vender
will deliver the remaining bottle by Feb 7, and Mike's request
for 2 more bottles should go into the system tomorrow.
Henry Sent PO request to Judy Meo for premix with 1% SF6,
4.6% isobutane, 35% Halocarbon 134a, balance argon.
Changed isobutane cylinder#1 to secondary (was primary) cylinder#2
to primary (was secondary).
Ray Rodriguez attempting to debug SIAM5, did not fix. Problem is that
gas shack alarms are getting through, but not being identified as RPC
Tightened set screw on purge valve on manifold of tank #2, was not working.
1-25-03 11pm. Freon input faults. Freon pressure is too low (after resetting
the faults pressure was 15psi and slowly falling, causing eventual trip).
Both freon tanks contain liquid. Regulator outside showing 50psi (should be
40). Raised pressure on regulator inside gas shack (3/4 turn) from 18psi
to 30 psi. Also the cryotech log sheet is already filled out for 5:50am
tomorrow! The online argone six-pack is currently 1200 psi.
date time epics led regulator
1-25-03 11:30pm 612 27.4 30
1-26-03 8:20am 765
1-20-03 Isobutane cylinder #3 replaced by cryotech MCS. Old was 94lbs, new
not weighted, nominal is 193lbs.
1-9-03 Spoke to Mike Racine. He will order a freon tank
today and another tank tomorrow. His purchase authority limit ($3500)
prevents ordering more than one at a time. Also he put in the isobutane
order on 12-20-02 but SLAC didn't enter it into the system in 1-2-03.
Called Mike Racine (2pm). Ordered another freon tank today. Will put in
additional order tomorrow. Isobutane bottles come from Houston. Looking at
delivery on Monday or Tuesday (DCH uses Matheson. Their bottles go from
Houston to East coast and then to SLAC, and cost $200 more than Air Gas).
Asked Robert to put full 120lb bottles on each freon
regulator. He must get new pigtale for one of the regulators. He will
also remove the two partial bottles and relabel the old bottle that
is neearly full. Scales check out ok. Note that the Matheson scales
(red/green dial) subtract the tare weight (set to 48lbs) while the
other (white dial) reads the total weight.
1-8-03 Robert reports that Jim McDonald does not permit us to
use one of their untested isobutane bottles and that purchasing
says there is a "good chance" for an isobutane bottle to arrive
- New freon tank connected. Mike Racine ordered another tank yesterday.
- Isobutane low (request was 12-20-02)
vendor estimates delivery on Jan 17! Not soon enough, so request
one bottle by 1-10-03. Can use one of existing DCH spare bottles if
Cryotech (Robert Moore) will get permission from Jim McDonald to use
DCH bottle in emergency. Robert also called purchasing to pursue
delivery of original bottles by Friday. Robert will follow up every
day this week until solved.
1-6-03 New tank still not connected. Simani called cryotechs and
left message to put online.
1-3-03 New freon tank arrived, but not connected to system. Left
message for cryotechs to connect and put tank on "standby."
1-2-03 Called cryotechs to check on freon tank order. Bob Hall
had SLAC purchasing call company. Will deliver tomorrow (tank coming
- 10:30am 1000lb freon tank (#3, South) installed and
online. Next tank expected Jan 2. Wes will move full 120lb
to rack with freon regulators.
- Freon on-line regulator is all the way open. During fill
regulator pressure is 36 psi while tank pressure is 45 psi.
- Requested (Wes and Mike Racine)
order of two isobutane bottles placed today.
- 9pm Trip caused by low freon pressure. 91 lbs. Reset
mixer, freon pressure failing (slowly) to 18 psi. Shut off bottle and
open 120lb bottle on tank#1 line (online).
- 1:52pm Gas sample (bottle #3) taken.
- 10:30am Old 120lb bottle 105 lb => 35 hours remaining
12-16-02 3pm Two new 120lb freon bottles arrive and are connected to
freon tank#1 and #3 input lines.
12-15-02 2am Power failure at IR2 caused IFR and DCH gas to trip. Howard
reset circuit breakers in gas shack and reset all faults. PTI pressure 1016 Torr
- 12:08 pm Filling, Pressure (epics) Ar, Iso, Freon: 621, 596, 573
- 12:20 pm Freon bottle weight 145 lbs => 37 lbs/day => 2.5 days left
- 8:30pm Gas shutoff because accelerator is down
- Trips caused by empty freon tanks. Tank requested on 10-30-02
was never ordered! Put small freon bottle online (~120 lbs) should last
at least three days. Cryotech Matt Neibal on duty, contacted Mike Racine.
Mike Will place emergency order Saturday or Monday for new 1000 lb tank,
should be available on Monday.
- At 9pm the small freon bottle weighted 168 lbs (TW=48lbs).
- Isobutane cylinder #2 replaced. Emtpy 86 lbs, new 198 lbs.
11-15-02 Measured flow rate on each endcap door:
Flow Press. Flow-161 Flow
WB 1429 349 1268 1.00
EB 1537 348 1376 1.09
WF 2080 341 1919 1.51
EF 1952 343 1791 1.41
All 2667 317
11-13-02 Wednesday, 3pm. Output pressure fault, no problems with argon
or isobutane. Reset and everything ok.
Tested output flow meter #5 (MKS Type 660 mod 120). Total IFR flow exceeds
meter max value. Barrel flow also exceeds max value, endcap door is
approx. half max value. Flow was shut off via the valves on the main
manifold on the outside of the barrel steel in IR2.
Epics In Gas Shack
Flow Press. Flow Press.
Flow off 161 372 272 9.8
EB door on 1529 348 3999 7.9
All 2667 318 7113 5.8
11-10-02 Sunday, 12:30pm. Argon ran out causing input fault. Six
packs #1 (east, online) and #2 (middle, standby) were empty. Put #3
(west) on online and shut off other two. Paged cryotechs to swap
empties and check for leaks.
10-30-02 Called cryotechs, requested new freon tank (#2). Asked techs
again to rotate tank #1 so we can connect it to the system.
10-28-02 Raised isobutane regulator on side of mixer from 24 to 26 psi.
10-27-02 11:30pm: Called shift leader to reset gas mixer from last night.
Input flow fault would not reset. Used maintence key to reset. During fill
noticed that isobutane pressure dipped close to 22psi, outside pressure
was 35pis. Next time at SLAC raise regulator pressure on mixer in gas shack.
10-26-02 9pm: Gas system trip. Argon pressure is too low, but EPICs panel
shows isobutane pressure fault. Isobutane pressure is fine. Davide says
the online and standby argon six-packs are empty. Turns on third six-pack
and says there is a leak at the three-way valve. Cryotech (Gary) paged.
Third six-pack is ok. Gary says there was a brief leak on the second
six-pack. Also says the first six-pack shows 1600 psi! Six-packs 1 and
3 are connected. Giants lose game six to Angels, World Series tied at 3-3.
10-1-02 Ordered two new isobutane bottles (Cryotech: Dennis)
9-27-02 Replaced isobutane bottle #2. Old bottle 74lbs, new bottle 199 lbs.
- Cleaned out clog in vent on freon tank #3 (sample of
sandy material that clogged the vent is taped to page in logbook
in the gas shack).
- Gas sample bottle #1
- Primary isobutane tank pressure 33psi, regulator pressure 33.5 psi
9-24-02 Ordered new freon tank (Cryotech: Wes)
9-23-02 Freon tank #1 empty, #2 online, #3 standby
8-21-02 Ordered new freon tank (Cryotech: Bob Hall)
8-19-02 Freon tank #3 empty, #1 online, #2 standby
7-19-02 Gas flow restored to RPCs in IR2. Spare supply line not in
use because it appears that someone else disconnected the distribution
panel from the spare supply inside IR2.
7-17-02 Repaced isobutane bottle secondary. Old bottle 85lbs. New
bottle (cylinder #1) 195lbs. Note new naming convention. Primary regulator
set to 40psi, secondary 30psi. Gas is not flowing because there will be
work on compressed air lines at IR2.
7-15-02 Isobutane manifold changes completed.
7-11-02 Ordered new freon tank (Cryotech: Dennis).
7-9-02 Cryotech Gary removed outside isobutane panel, noted extra
relief valve on one line, proposes additional modifications. Contacted
HEEC for approval.
7-8-02 Freon tank #2 empty, #3 online, #1 standby. Took gas sample
bottle #2. Shut off gas mixer and opened supply lines to air in IR2
in preparation for isobutane modifications.
6-18-02 Switched spare supply line from argon to mixed gas.
6-11-02 Freon tank #3 on standby, #2 is online.
manifold modifications with Mike Racine. Need 1 week installation.
New parts will cost $1k (includes new regulators and gauges). Nando/Bill/Henry
choose July 8-14 for installation.
- To Mike Racine: Requested new braid on freon tank #3 and
tank rotation. Requested new manifold (a la argon/freon) for easy
bottle replacement and mods to isobutane supply so that regulator
gauges can be replaced.
- From Mike Racine. Compressed air leak on 5-28-02 was due to operator
error and affected the entire site. Not caused by BaBar, nor was there
anything that BaBar could do. Installed check valve on supply to BaBar to
prevent backup bottles from being depleted. Dessicator o-ring should not
- Replaced empty primary isobutane bottle: Old bottle 72lbs, new bottle
- Took gas sample bottle #3.
6-3-02 Ordered new freon tank (Cryotech: Lester).
5-31-02 Freon tank #1 (North) empty. Tank #3 has kink in braid and should
5-28-02 Owl Shift. Site compressed air supply failed due to leak. Eventually
repaired. The leak was caused by (SLAC) operator error and was not found for
quite some time.
5-2-02 Requested new freon tank and two isobutante bottles from Cryotech: Dennis.
5-1-02 Freon Tank #3 (South) is empty, put #2 on standby, #1 online.
Isobutane secondary is empty. Old bottle 74lbs. New bottle 197lbs.
Order more freon and isobutane.
4-10-02 Called Chris Harvey (LLNL Chemist running
Mass-Spec. analysis). Latest gas analysis on sample taken 3-11-02 was
run three times (on three different days). Results are consistent, and
include 0.25% N2. I asked him to recalculate if ignoring N2 and the
fractions changed only by delta of 0.1%, so this is not a significant
3-12-02 Called cryotechs (Mike). Asked to order two freon tanks and complain to Airgas about half filled isobutane bottle
- 6:20pm Switched spare supply line back to argon (was mixed gas)
- Replaced empty isobutane tank (primary) old 86 lbs, new 187 lbs
- Found new isobutane tank was half full (valve was covered with
plastic, so it was not used yet). Net Wt. 124 lbs, TW 68 lbs, label
indicated 116 lbs of isobutane.
- Freon tank empty (#2 middle)
- Freon tank (#3 South) put online
- Took gas sample (bottle #2)
3-8-02 From Swetha Reddy (for Butch Byers)
Isobutane usage Calendar 2001
IFR 1020 lbs
Tot 2436 (limit is 2600)
3-4-02 Switched extra output flow supply to mixed gas (was argon
for remediation test). Bill Wisnewski in the gas shack and Doug Wright
was on the phone. Note that we first relieved the argon pressure through
the IFR vent.
3-1-02 Freon tank empty (#1 North)
2-21-02 Timed gas cycler: 32 minutes cycler on, 15 minutes cycler off with output flow of 7113.
R = r(1+t/T) R = input flow; r=output flow
T = time duration of cycler on
t = time duration of cycler off
1-30-02 Rotameters on each corner of detector:
Gilmont Instruments Model 65 mm (glass length is 65mm)
Scale is non-linear from 0-120
According to part #, endblocks are aluminum, and scale is "Direct Reading"
as opposed to calibrated.
1-29-02 Adjusted isobutane regulator (takes time for bottle to warm up)
- Requested cryotech (Wes) to order and install new freon tank #3
- Replaced empty isobutane bottle
- Take gas sample bottle #3
1-22-02 Freon #3 (South) ran out
- Installed 9-flow test-gas manifold in IR2 to spare gas line to gas shack.
- Found and fixed three leaks on stainless connections on spare line in
- Tested switchover from argon to mixed gas. Should disable IFR cycler when
opening valves to put argon in spare supply line. Don't forget to renable
the cycler when after the valve is fully open.
- 5:25pm Set flow to 3cc/min (nominal) of pure argon to test-gas manifold at 6psi
12-7-01 Requested cryotech support from Mike Racine for the following:
- Replace gauges on test-stand regulator, bottle 200psi max output 20-50psi max
- Connect shunt on extra gas line
12-7-01 Requested cryotech (Matt) to
- order new isobutane, two empties
- Order new freon tank (#1 North), cryotechs should disconnect and connect bottle when it arrives
12-5-01 Gas sample taken bottle #1, Isobutane primary empty, Freon #1 (North) empty
11-19-01 Requested cryo-tech (Robert) to rotate new freon bottle, so valve faces the manifold
11-02-01 Requested new freon bottle from cryo-tech (Gary)
Mike Racine: Normally order Standard Grade argon (99.995% 60$ per six-pack),
but in Aug 01 cryo ordered Ultra High Purity (UHP 99.9995% 400$ per six-pack) by
mistake. Requested approval to order standard. Approved.
10-30-01 Connected new freon tank (#3), disconnected empy (#2), replaced empty isobutane bottle
10-16-01 Requested labels on freon manifolds (to Mike Starek, completed by Gary 10-30-01)
10-12-01 Replaced empty isobutane bottle, connected new freon tank
9-18-01 Gas sample taken
8-?-01 Freon manifolds installed, similar to new argon manifolds
8-14-01 House compressed air line has leak, causing valves to close. Flow
stopped and caused fault. Cyrotech (Mike Starek) repaired leak
(o-ring in dessicator had disintegrated). He also replaced the backup air
cylinder since it had run empty during the leak.
6-01-01 Adjusted argon regulators
Took gas sample
Moved belly band on freon tanks
5-25-01 Adjusted argon regulators
Met with Mike Racine and Art Candia about cryotech tasks and gas system modifications
5-15-01 Adjusted argon regulators
Changed isobutane primary (old=83lbs, new=188lbs)
Swept morning dove out of argon gas tent
5-12-01 System trip when isobutane primary ran out (raised pressure on secondary)
4-4-01 Changed argon six-pack
3-28-01 System trip when isobutane secondary ran out (raised pressure on primary)
Changed isobutane secondary (old=80 lbs, new=198)
3-7-01 ordered 50 gaskets for sample bottle Cajon NI-4-VCR-2
3-7-01 2pm Output Gas Fault. Everything was fine. Reset and ok. PEPII had just started injection.
2-9-01 Gas sample taken (bottle 3)
2-1-01 Changed isobutane primary (old=90 lbs, new=201)
1-25-01 Gas sample taken
1-18-01 3:30pm Mix changed, hypernews posting
1-10-01 Gas sample taken
11-17-00 Gas sample taken
11-10-00 Mix changed
flow controller target
reading dial-setting fraction
argon 4.49 9.02 65.5%
isobutane 1.55 3.17 4.5
freon 134a 9.00 9.02 30.0
7-31-00 Mix changed (3:20pm)
flow controller target
reading dial-setting fraction
argon 3.56 60.5%
isobutane 1.33 4.5
freon 134a 9.00 35.0