Which CO analyzer to get? The Analox EII or the ToxiRAE 3?

[WOODMAN]

I am putting this in the Cozumel forum because that is where all of the discussion on this seems to be, and there is virtually no info on the computers and analyzers forum. I am interested in upgrading my CO tester from my old Pocket CO monitor (incredibly slow and cumbersome), to one of the more modern units. I am considering the Analox EII CO tester vs. the ToxiRAE 3 unit. The Analox is about twice the price of the ToxiRAE, but seems like a simpler and easier tester to use. It also looks more durable. The ToxiRAE seems to be unusually complicated, from what I could glean from their web site, and I was wondering if anyone has any practical experience with it? Do you just hold it in place and crack a valve onto it, or do you have to go the plastic bag route, like the Pocket CO? Any first hand reports would be greatly appreciated. Woody

 

[TomZ]

I've only used the Analox tester.

I have an Oxycheq restrictor that goes onto the BC fill hose. The Oxycheq threaded dome: Expedition Flow Cap : OxyCheq - DiveOps, Analyzers and Scuba Diving Equipment

plugs into the restrictor: Expedition BC Flow Restrictor : OxyCheq - DiveOps, Analyzers and Scuba Diving Equipment ,

which only allows a small trickle of gas to flow. After getting a oxygen reading, I unscrew the dome from the sensor, and hold the Oxycheq dome directly onto the dome of the already calibrated Analox CO tester: EII CO Carbon Monoxide Analyzer: Analox - Looking after the air you breathe.

Simple, quick and easy. I could even do in in a panga at speed. You could probably hook up some kind of manifold and test simultaneously, but the gain might not be much. Make sure when you're using it there's no CO source nearby, like an idling outboard that will give you a crazy high baseline. Don't ask how I know this.

 

[swamp diver]

I have both units and have used them extensively.

If you have no intention of adding a CO monitor to your compressor then I'd probably go with the Analox CO EII. It is easy to use, splash resistant, and most importantly backed by a company which specifically designs products to protect divers' breathing air. Have a look at the unit's manual on the web site and you can see the level of detail (i.e. research into helium mixes and CO testing) Analox has put into this unit. It is nice to be able to test right off the tank instead of having to use a flow restrictor although this can be a big problem on a boat if there is any ambient CO around due to the exhaust. At least with the flow restrictor method one can isolate the unit from the ambient environment. This can be done with the Analox unit but one must purchase their calibration kit in order to get the calibration dome with barbed nipple. Cost of that is about $75.

That being said the ToxiRae3 is about half the price of the Analox unit and is very durable. I've dropped it a least a half dozen times and it still keeps on working. There has been some issues with the black plastic cap (see below) friction fit in that it becomes loser over time and can fall off. One can buy replacement caps for $5.

The other issue which people forget to consider is that both of these units will require a formal calibration every 6 to 12 months (the Oxycheq one does as well) and with the ToxiRae3 this will mean purchasing the calibration gas and regulator which might set you back $300. With the Analox unit your shop might have the calibration gear and charge you a fee to do it, or if not Analox in California will do the calibration for a fee.

If you don't have a compressor I'd probably go for the Analox unit.

 

[DandyDon]

Analox...!

Jbtut said he uses his Toxirae 3 in a bag instead of the hose hookup, but I don't know about that approach - even tho it did seem to work for him on http://www.scubaboard.com/forums/co...ving-2-26-12-had-one-tank-read-12-ppm-co.html thread. Suprane has the Toxirae 3 with low pressure hose hookup and I got him to try my Analox on a trip, and he's stated he wishes he had the Analox instead. I have a hunch that he will in time.

Some of the companies are now claiming that their units do not need to be calibrated, but I'm sending my Analox analyzer in for that before my next trip.

 

[swamp diver]

Analox...!

Jbtut said he uses his Toxirae 3 in a bag instead of the hose hookup, but I don't know about that approach - even tho it did seem to work for him on http://www.scubaboard.com/forums/co...ving-2-26-12-had-one-tank-read-12-ppm-co.html thread.

Yes you can use that method as well. Unlike the Pocket CO which takes 3 minutes to achieve a reading the ToxiRae3 is the fastest sensor on the market and will read 90 percent of the final reading in 12 seconds.

 

[WOODMAN]

Yes you can use that method as well. Unlike the Pocket CO which takes 3 minutes to achieve a reading the ToxiRae3 is the fastest sensor on the market and will read 90 percent of the final reading in 12 seconds.

So, how fast is the Analox in comparison? It looks like you just crack a tank valve slightly and hold the sensor up against the valve while triggering the unit, am I right? I believe you can add a BC hose adapter with flow restrictor which will plug into the end of your BC fill hose; but this is added complexity and cost, for marginal gain (or so it appears to me...). ???? Woody

 

[DandyDon]

I don't care for the BC hose connection as I like to test the tank before putting my gear on it. The Analox manual says to test for 30 seconds of flow, but I think you will see it react or not in like 10 seconds.

 

[WOODMAN]

I don't care for the BC hose connection as I like to test the tank before putting my gear on it.

Good point.

 

[Scared Silly]

The Analox has the same flow restrictor as does their O2 monitor. Actually the whole design is based on their O2 monitor. I have an Analox as well as the ToxiRae. The ToxiRae needs the BCD adaptor whereas the Analox does not and there is no need to use an adaptor for it either.

Both units are god units. I started with ToxiRae because that was the best option at the time. Though I now use my Analox more often. In fact I have ToxiRae up for sale only cause I do not need both.

 

[swamp diver]

So, how fast is the Analox in comparison? It looks like you just crack a tank valve slightly and hold the sensor up against the valve while triggering the unit, am I right? I believe you can add a BC hose adapter with flow restrictor which will plug into the end of your BC fill hose; but this is added complexity and cost, for marginal gain (or so it appears to me...). ???? Woody

What you are asking for is the T90 response time. Have a look at section 10 here on page 22 and Analox reports the T90 of < 20 seconds which still very fast compared with the older sensors.
http://analox.net/product-docs/manual-91.pdf

I don't see a video of the CO EII specifically but how one uses it is identical to the nitrox unit as shown in this clip.
How to use an Analox O2EII Nitrox diving analyser - YouTube