What are you using to test for CO?
Air testing personal SCUBA compressors
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What are you using to test for CO?
frogman62
Contributor
I have used TRI for several years and tested all to the NAFTA standard one grade above E for fire departments and my commercial compressors. One thing I liked was the dewpoint of -60 degrees or better. I always tested the air prior to changing the filters so I know that what is in the bank is still good air. Testing it after a filter change should always have a good reading.
Jim Shelden
Jim Shelden
Visual moisture indicator with a Texas Technologies 10/20/30% RH disk.
- Scuba Compressor
You want the black applicances the older gold colored visual indicators have funky cut glass in them that's hard to see through.
You'll find the disk will go from ~10% RH to >30% RH rapidly which is a sign of moisture breakthrough. The 13x is at water capacity and the AC will be barely functioning at this time so you are relying on the backup filter to catch the excess water and any hydrocarbons passing the 1st AC bed. A 16" tower has got enough capacity to catch this stuff until you change the primary filter (30mins-hour of running potentially the RH disk doesn't change instantly and you may want to finish a tank etc). 13x always gets water saturated before oil (unless there's a huge system disfunction which a periodic air analysis won't catch anyway).
The disks can be reused many times just hold them with tweezers and run a hair dryer over them for a few minutes and it will turn a baby blue again. "lavender" or used up, is really sorta pink to me.
there are other threads here on CO production and testing, DandyDon has looked into current model CO analyzers more than me.
Thanks for the info. Are you using the LF filter cartridge in the first filter housing or packing your own?
I have been following DandyDons threads, good stuff. I tried to get the Analox tester but they are now back ordered by two months. I ordered the pocket CO and will use it till some thing better comes along.
We have three gas testers at work that monitor O2, CH4, and CO, I borrowed one and thought that would work well. Not that I expected to see any CH4. But unfortunately it didn't work to well. The O2 sensor only went to 30% and above 30% went into alarm mode, then it turned out that Helium set off the CH4 alarms. So I could not test nitrox or trimix with it. I was putting it in a zip lock bag and filling the bag with a second stage, gotta be a better way.
The primary filter I hand pack. Its basically a Bauer P0 size & design
My secondary which I change at 60hrs is a LF triplex cartridge. 60hrs is basically the rated capacity. I figure with pre-filtering this is a reasonable change schedule, the moitsure indicating strip in this filter has never even started turning pink. Then again I'm not using it as a primary filter its function is mostly backup and a slight amount of air quality "polishing" so I have full confidence I'm meeting OCA standards (I have tested in the past, I just stopped because it wasn't telling me anything I didn't already know)
My secondary which I change at 60hrs is a LF triplex cartridge. 60hrs is basically the rated capacity. I figure with pre-filtering this is a reasonable change schedule, the moitsure indicating strip in this filter has never even started turning pink. Then again I'm not using it as a primary filter its function is mostly backup and a slight amount of air quality "polishing" so I have full confidence I'm meeting OCA standards (I have tested in the past, I just stopped because it wasn't telling me anything I didn't already know)
BW Technologies Gas Alert Extreme
Since I bought this unit there have been other developments and there may be better and cheaper analyzers out there. I've invested in this one and I'm sticking with it.
Harry, are you using the zip lock baggie method to test with this?
Is your primary filter the stock Alkin unit?
Sounds like you have the moisture detector right after the primary filter and feed thru it to the secondary?
I'd be interested in seeing a picture of your setup. Harry sent me pictures of his a while back and that motivated me to get my W31 off the floor and on a cart and set up the second filter. Thanks.
The stock Alkin unit on the W31 = a Bauer P0 filter. Its tiny, try not to rely on it. If you are relying on it, change it more frequently. The temp correction table for this filter in the manual is WRONG. Its very very wrong. I told Bruce at Airtex about it and the CPSC and neither did anything. Basically they used compressor inlet temp as = to filter inlet temp. If you roughly add 30-40F to ambient temp you are much closer to filter inlet temp. But bottom line is, don't use that temp correction table.
I moved last year and don't have any current pictures. But basically mine goes in this order.
I can disconnect the nitrox stick and compressor from the banks and whips on the wall at the QD in #8. I can convert the compressor to gas power and hook a DIN fitting on this QD for mobile continous nitrox blending. In this mode I only have the P0 filter on the compressor. I've never put more than a few hours on the compressor on the road so I just use a fresh one and throw it out long before its spent. I've never had one exceed water standards at <9hrs at home so I have some confidence that if I've only put 3 or 4 hours on a fresh one away from home its fine. When using the compressor under gas power I use the prepackaged triplex cartridges. At home I have the secondary LF triplex cartridge so I hand pack the primary.
I moved last year and don't have any current pictures. But basically mine goes in this order.
- Inlet
- nitrox stick
- O2 sensor
- extraction port for Hargraves 2L/min gas pump to analyze trimix inputs
- oversized hose
- W31 compressor
- P0 filter on compressor
- QD connection
- 10/20/30% RH moisture sensor
- bleed screw
- 16" triplex LF tower
- 18-2000psi backpressure reg
- 10/20/30% RH sensor (this never does anything my compressor guy gave it to me yrs ago)
- PP blend, and bank manifold (there's a bleed off reg on the manifold for post compression trimix analysis)
- fill whips with DIN fittings in QDs
I can disconnect the nitrox stick and compressor from the banks and whips on the wall at the QD in #8. I can convert the compressor to gas power and hook a DIN fitting on this QD for mobile continous nitrox blending. In this mode I only have the P0 filter on the compressor. I've never put more than a few hours on the compressor on the road so I just use a fresh one and throw it out long before its spent. I've never had one exceed water standards at <9hrs at home so I have some confidence that if I've only put 3 or 4 hours on a fresh one away from home its fine. When using the compressor under gas power I use the prepackaged triplex cartridges. At home I have the secondary LF triplex cartridge so I hand pack the primary.
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