Analox CO Bump Testing Schedule

[Blue Sparkle]

Page 8 of the manual. Section 2.5 #2 reads:
2. Ensure that the instrument has been zero calibrated (see section 3.1) and bump tested (see section 3.2) before checking your tank.

I haven't bought one of these yet (although it's on my future list), but .... that instruction sounds vague to me -- unless there is further specific info in Section 3.1?

For example: When I dive, I ensure that my regs have been serviced.
But that doesn't mean I service them prior to each dive.

It would be nice if they added more information to specify not only that the analyzer be bump tested and zeroed, but how often and when.

Example:
Bump test at least once every six months.
Bump test prior to use if analyzer has been idle for over two months.
No more than 10 days should elapse between most recent bump test and active use of unit.

(Or whatever - I just made that up as an example of a more-specific type of guideline; it has no connection with the analyzer or with reality.)

This way you would know how often you need to bump test it when it is in active use.
You would know that even within the "good" time period it cannot sit idle without needing a re-bump.
You would know how far ahead of using it you can do the bump test.

I wouldn't feel confident with the instructions as presented from the manual (unless there is more detail elsewhere withing). And yet, I would be annoyed if I were bump testing it each time completely unnecessarily.

Blue Sparkle

 

[beautybelow]

I just spoke with the guy who sells the CO analyzers here. When I first talked to him we had a zillion other things we were talking about so the bump gas wasn't really addressed properly.

He said that his advise would be to do a bump test once a month if using regularly.

I know he sells it, but we are in a position that he doesn't make anything off of selling it to me, so I take this as his advice, not sales pitch.

 

[jar546]

I think for liability purposes the manufacturer wants you to bump test it before each use. It does not work for practical purposes, especially if you are traveling.

 

[Jax]

The purpose of the bump test is to show the sensor senses and correctly reports the presence of CO.

Why would one need to retest every time? Is the sensor that wonky? If that was necessary, I find the the analyzer is not designed well and would not trust it.

I would, however, test it when conditions are different (say, a low pressure system moves in), or after 10-12 uses. Just to check.

 

[tadawson]

Note also that Analox specifies in the manual that a full calibration is to be done every 6 months in order to "meet published specifications". If you only bump test, then they state that it is valid as a go/no-go tester only (IE, you know what you read is bad, but have no confidence in the specific figure). That also explains the 7% to 13% reading required on a bump test . . .

I would think a bump prior to each outing or period of non-use to verify function would be good.

Now if I can just get my shop to sell the test kits, that would be nice . . . . I asked how they could sell a CO monitor with no means to verify that it works, and got some blank stares, but hopefully, they will start to carry the bump gas . . .

- Tim

 

[beautybelow]

Yeh....these analyzers aren't a bullet proof piece of high tech equipment (not saying they aren't well built) and we use them in a pretty harsh environment. I don't think they will get the abuse the O2 testers get, but it's my understanding or viewpoint that if you are going through the motions to test the gas you are producing you should do it right. Testing it against a "known" level of CO every once in a while as opposed to a car exhaust will actually calibrate it. If you aren't really checking the piece of equipment every once in a while you are really "just going through the motions".
Especially if you have a system you are monitoring on a regular basis and are watching for any changes at all.

 

[Blue Sparkle]

it's my understanding or viewpoint that if you are going through the motions to test the gas you are producing you should do it right....

I agree with that. Where it seems confusing to me (going by the posted instructions from the manual) is... what IS right?

To me, the following:

Ensure that the instrument has been zero calibrated (see section 3.1) and bump tested (see section 3.2) before checking your tank.

Doesn't really give me enough information to know what I should be doing. Ensure it was bump-tested just after I bought it? Annually? Each time I use it? Like I said above, I "ensure that my regs have been serviced before I go diving," but that alone doesn't tell me how often to do it (luckily, for regs, I do have more information to guide me).

I have this unit on my "consider buying" list, but I would want more data on what exactly I need to do (and what I don't need to do) to keep it operating as well as possible.

 

[Hudson Hawk]

As the manufacturer of the EII CO we recommend bump testing before each use however, should the gas be unavailable because of travelling restrictions or availability, regular periodic testing is better than nothing.

Ensure that the instrument has been zero calibrated (see section 3.1) and bump tested (see section 3.2) before checking your tank.

To prep for the bump test turn the black adjustment so the display reads 0 in clean air i.e. not next to or down wind of an exhaust outlet or an area which may have higher concentrations of CO. Then use the bump test gas to bump the reading to 10ppm CO. If your reading following the bump test is 10ppm you are ready to analyse your gas. You need to allow the unit to 0 before testing.

To demonstrate we have created this short video on bump testing How to bump test your EII CO analyser - YouTube

Regarding Calibration - if you bump test and your EII CO is reading correctly then there is no need to go through the calibration procedures however you may wish to arrange a test and calibration as part of your routine gear service.
If you have any question on gas availability or where you can buy the Analox EII CO then let me know EII CO Carbon Monoxide Analyzer: Analox - Looking after the air you breathe. - michelle.hudson@analox.biz

 

[Peter_C]

Since a CO meter is HIGH on the list, as in this year, I was researching them and came across this thread. There seems to be two meters aimed at traveling scuba divers. One made for Oxycheq/Nuvair, and the other being the Analox. I think the Nuvair is the one for us since it will sit on a shelf nicely while filling at home. I already have the LP inflator hose connector fitting so it would just plug into my reg testing stand thru a regulator to monitor gas continuously while pumping nitrox. Also if I put the CO meter and an O2 meter into a water proof box together they could both be hooked to the same LP connector allowing air analysis in a matter of a few seconds. The Nuvair has two settable audible alarms that can also shut down the compressor when an alarm setting is reached.

For the bump gas or what in our case will be calibration gas, a simple CGA 600 fitting with a regulator followed up with a flow meter should suffice. Cost well they are over $150 to buy or I can walk out in my garage and build one from components I already have for the cost of the flow meter. CGA 600 is used for propane and you can buy calibration gas in a 10 ppm mix inside a larger propane bottle sized container to allow for more (Cost effective) testing of the gas analyzer.

According to Nuvair the calibration only needs to be performed once a week. Sounds to me like a test before leaving for a trip should be good enough. If in Mexico the air near most any busy street should read a high enough concentration to confirm it works.

 

[jar546]

The bump kit for the Nuvair seems to make it a little costly