Anyone Have Experience with Sensorcon CO Analyzers?

[TrimixToo]

I found these online:

Carbon Monoxide Detector for SCUBA Tanks

...and the price, including bump gas for recalibration, seems pretty reasonable. Does anyone have experience with this company? A new analyzer costs less than the replacement sensor for some other detectors.

 

[TrimixToo]

So, it eventually came down to Sensorcon or OxyCheq. Considering the cost of the calibration gas, replacement sensors, and bump gas, they were almost identical in ownership cost over 5 years or so. Advertised accuracy and resolution are similar. They both have alarms, but the OxyCheq alarm goes off at lower level of CO, 10 PPM vs. 35 PPM.

Sensorcon's very low purchase price ($169) is really tempting but calibration gas is $245 for 35 calibrations' worth, and I didn't find information on sensor replacement cost--though at $169 you could just buy one every time the old one stops calibrating. I called for more information, but Sensorcon wanted me to leave a message whether I wanted customer service or technical support, and promised to call back within 24 hours. So for now, let's say the 5-year cost of ownership is two analyzers at $338 total plus the calibration gas for $245, for $583 all together.

The 5-year COO for either the Sensorcon or the OxyCheq beats the cootwo's handily. For the cootwo, the $300 purchase plus four sensors and calibrations at $130 a year total over $1K. For the OxyCheq, with its 3+-year sensor life it's $400 for the analyzer, one sensor at $140 with $29 for test gas for a total $569.

OxyCheq answered the phone on the second ring, and the guy was very helpful. $20 more for a company that answers the phone in case I have a problem is worth it to me. I should have it in a few days (Saturday if I'm lucky).

One other consideration: The OxyCheq calibrates at 15 PPM and the Sensorcon calibrates at 50 PPM. I'd rather have the calibration done at a value closer to the maximum safe value for the diving I do than at 50 PPM. This is the OxyCheq:

OxyCheq - OxyCheq Expedition CO Analyzer w/ Alarm

 

[Joneill]

The 5-year COO for either the Sensorcon or the OxyCheq beats the cootwo's handily. For the cootwo, the $300 purchase plus four sensors and calibrations at $130 a year total over $1K. For the OxyCheq, with its 3+-year sensor life it's $400 for the analyzer, one sensor at $140 with $29 for test gas for a total $569.

I think you are misrepresenting the COO of the Cootwo. Why would you buy 4 new CO sensors for a Cootwo in 5 years? The sensors are recommendeed to be calibrated annually but are good for at least 2 years - just like all the CO sensors out there (I'm very skeptical that Oxycheq really has a longer shelf life that the others?). I'm pretty sure they all use the same electrochemical sensor technology that has a limited lifespan and needs periodic (annual) calibration to maintain best accuracy - so if you factor in annual calibration on the Cootwo, you should do the same for the others.

Also, you should be looking at the price of the Monox and not the Cootwo as the others are just CO analayzers. The MonOx is $229 and the replacement CO sensors are $69. Bump gas would be the same for any of them if you do the calibrations yourself.

If I take your approach with Monox, I get a 5 year COO of $367- $436

• unit - $229
• replacement sensors - 2 @ $69 = $138 or, more conservatively 3 @ $69 = 207

To that you'd need bump gas to calibrates or you could send to Divenav to calibrate for $49 bu t, to be hionest, the buy bump gas/calibrate yourself option makes the most $ sense for all the items.

 

[Darghu]

How do we know our CO analyzer do need a calibration? Cause gas detection is pretty close between 0 - and 15 ppm what if the measurement are corrupted?

Would you dive even with a 5 ppm?

 

[TrimixToo]

I think you are misrepresenting the COO of the Cootwo. Why would you buy 4 new CO sensors for a Cootwo in 5 years? The sensors are recommendeed to be calibrated annually but are good for at least 2 years - just like all the CO sensors out there (I'm very skeptical that Oxycheq really has a longer shelf life that the others?). I'm pretty sure they all use the same electrochemical sensor technology that has a limited lifespan and needs periodic (annual) calibration to maintain best accuracy - so if you factor in annual calibration on the Cootwo, you should do the same for the others.

Also, you should be looking at the price of the Monox and not the Cootwo as the others are just CO analayzers. The MonOx is $229 and the replacement CO sensors are $69. Bump gas would be the same for any of them if you do the calibrations yourself.

If I take your approach with Monox, I get a 5 year COO of $367- $436

• unit - $229
• replacement sensors - 2 @ $69 = $138 or, more conservatively 3 @ $69 = 207

To that you'd need bump gas to calibrates or you could send to Divenav to calibrate for $49 bu t, to be hionest, the buy bump gas/calibrate yourself option makes the most $ sense for all the items.

If you're right, then I must have misread what was on the Divenav site, as I thought the annual calibration incurred sensor replacement at the same time. So with your numbers, using the cootwo, this puts them all into the same ballpark. I don't see the Monox, only the Cootwo, on the Divnav Products page, here:

DiveNav - Products

As the other two self-calibrate, the bump gas also takes care of calibration. If you can likewise calibrate a cootwo in the field, then its COO could be lower, but I didn't find that information on their site, either. However, the cost of bump gas varies, and they don't all use the same concentration of CO for calibration.

 

[Joneill]

If you're right, then I must have misread what was on the Divenav site, as I thought the annual calibration incurred sensor replacement at the same time. So with your numbers, using the cootwo, this puts them all into the same ballpark. I don't see the Monox, only the Cootwo, on the Divnav Products page, here:

DiveNav - Products

As the other two self-calibrate, the bump gas also takes care of calibration. If you can likewise calibrate a cootwo in the field, then its COO could be lower, but I didn't find that information on their site, either. However, the cost of bump gas varies, and they don't all use the same concentration of CO for calibration.

The CO sensor does not need to be replaced when calibrating.

The MonOx is new and seems to only be in the store section:

monOx - DiveNav Store

I'm not sure what you mean by "the other two self-calibrate"? The Cootwo/MoxOx can be CO calibrated by the user if you buy bump gas - you need a "zero" CO reference gas and a CO reference gas (they reco 10, 15 or 20 ppm, I believe - you enter what you used into the unit during calibration). I would imagine that the zero reference/bump gas requirements and calibration processes are similar with the other 2 units too?

ediving.us • View topic - cootwo & monOx: Carbon Monoxide sensor calibration

 

[Darghu]

I read that you need 2 gas, 0 ppm and another one - 10 or 20 or 30 whatever.

Carbon Monoxide Calibration Gas in Air

 

[TrimixToo]

The CO sensor does not need to be replaced when calibrating.

The MonOx is new and seems to only be in the store section:

monOx - DiveNav Store

I'm not sure what you mean by "the other two self-calibrate"? The Cootwo/MoxOx can be CO calibrated by the user if you buy bump gas - you need a "zero" CO reference gas and a CO reference gas (they reco 10, 15 or 20 ppm, I believe - you enter what you used into the unit during calibration). I would imagine that the zero reference/bump gas requirements and calibration processes are similar with the other 2 units too?

ediving.us • View topic - cootwo & monOx: Carbon Monoxide sensor calibration

Yes, but with a single bump gas to calibrate each one. By self-calibrate, I mean they can be done in the field, by the operator, like the monOx and cootwo. Being on the store page but not the products page explains how I missed the monOx. The store pages have a lot more info.

They don't sell the bump gas as far as I can tell. Except for OxyCheq, the places I found that do sell it sell a small tank of it with a regulator and hose, in the $225-$345 range depending on how much gas you get. So let's look at 5-year COO for the monOx.

$229 for the monOx, another $225 for bump gas, unknown cost for 0 PPM test gas, and $70 for the sensor every two years. $225 + $140 is $365 vs. $429 for the OxyCheq, but that leaves out the 0 PPM test gas. Or, you can send it in for four calibrations at $60 each, including shipping back to you, for $240, adding $15 for a total of $380.

If you trust a zero reading from the monOx for a tank you can mark and dedicate to using once a year, maybe you can use that for the zero test, but then you have to factor in the cost of the tank ($100 for a 6 cu ft pony from Leisurepro today), or the cost of a tank of actual 0 PPM calibration gas, which I did not research.

Back to the cootwo, for which I missed field calibration and 2-year CO sensor life, but also missed the 1-year O2 sensor life, while most O2 analyzers use a sensor that costs about the same but usually lasts 5 years. So to the above, add $75 plus an O2 sensor every year at another $280.

With any luck, I've added things up right this time...

 

[Darghu]

0 ppm can be 100 ‰ argon? 100% N2? Co2? Something less expensive who must be pure

 

[victorzamora]

My Sensorcon CO meter died in a few months. Response from the Mfgs was "we can sell you a new one at full price." Thanks, guys. Been using my buddy's COOTwo since then, which will be my next CO analyzer.