AnotherThreadAboutCOanalyzers

[DandyDon]

Realistically anything over zero is cause for concern. You don't splice hair over this, its easy to make gas with NO Co and if any is present that means the fill station is suspect.

True, but measuring in 1/1,000,000 units is challenging, especially outside of a lab and a boat with varying ambient conditions. Personally, I'll ignore a few digits on a reading as a possible user error or just too close to take seriously with sensor variations. That's a personal call, but I'd skip a dive if I couldn't read less than 5ppm for a hundred feet dive plan, or less than 10ppm for a shallow one - then have a chat with the owner.

 

[rjack321]

True, but measuring in 1/1,000,000 units is challenging, especially outside of a lab and a boat with varying ambient conditions. Personally, I'll ignore a few digits on a reading as a possible user error or just too close to take seriously with sensor variations. That's a personal call, but I'd skip a dive if I couldn't read less than 5ppm for a hundred feet dive plan, or less than 10ppm for a shallow one - then have a chat with the owner.

Right. I mean my unit flitters around -1 to 1 on most cylinders. I have gotten a "2" once or twice which didnt stress me out for recreational diving.

But a solid 4ppm? Yeah that isn't right. I would not dive 8ppm, sensor calibration and age vary and for all I know its linearly limited and the true value is 18ppm or worse. None of these are precision laboratory instruments calibrated and operating in good conditions.

 

[Curious_George]

Nows your chance to get a great deal and support a US manufacturer. Two years and mine is still working perfectly. Sensorcon

Right after I got my CO sensor I was testing tanks from my gas powered portable compressor and found 20ppm CO. I guess the breeze was swirling that day. I saved that tank and use it to test my sensor periodically. Still reading very accurately within 1-2ppm Almost 2 years later.

For the nay-sayers: yes, if you blast high pressure air across the sensor, it will read crazy.

For those who’ve not tested - I hope your trust isn’t misplaced.

 

[DandyDon]

Wow, such a nice deal. Any diver can afford $99 to avoid a hit. You have to wonder how many Travelers Flu cases were really hits, not to mention diver drownings.

Still reading very accurately within 1-2ppm Almost 2 years later.

The last time mine came up for biennial battery and sensor replacement, I caught a special like this and just bought a new one, leaving the old one laying on the counter here. I leave mine on 24/7 as a room monitor, traveling protection, etc. Hardly any hotels have CO alarms in their rooms but they all have water heaters and other sources. It's over three years old now and still working, still responds to CO tests. They claim that the chip program automatically adjusts to sensor drift. True or not, at least it'll keep you alive.

 

[Agro]

Realistically anything over zero is cause for concern. You don't splice hair over this, its easy to make gas with NO Co and if any is present that means the fill station is suspect.

Can you measure zero? No you can not. Nobody can. Depending on you measuring device you can measure zero +- whatever, but not zero.

Anything over zero is what we have on this planet. In free nature we habe about 100 ppb (billion, not million), in a living room you often find 5 ppm, at New Delhi you probably find 200 ppm.

 

[Agro]

What is the price for a sensorcon replacment CO sensor? I did not find this on their website....

 

[rjack321]

Can you measure zero? No you can not. Nobody can. Depending on you measuring device you can measure zero +- whatever, but not zero.

Anything over zero is what we have on this planet. In free nature we habe about 100 ppb (billion, not million), in a living room you often find 5 ppm, at New Delhi you probably find 200 ppm.

My living room, even when my woodstove is burning is zero.
5ppm would be very poor ventilation.

200ppm? You're 2 orders of magnitude too high. CO is 1 to 5ppm in New Dehli Spatial variability of concentrations of gaseous pollutants across the National Capital Region of Delhi, India

 

[Agro]

What kind of measuring unit do you use?

 

[DandyDon]

What is the price for a sensorcon replacment CO sensor? I did not find this on their website....

Calibration service is $49USD but only available to US. Sensorcon Inspector-Calibration service What I don't remember for sure if that includes sensor replacement or not, and I can't call today. Someone remind me tomorrow morning. Or I am sending an email for clarification now so if they respond quickly, I can probably remember to find this thread and post then.

I would not attempt battery & sensor replacement plus calibration on my own when a new unit is so cheap, but for someone more confident in their skills and who already owns the tools, I'm sure that the batteries are cheap and easily found and the sensors are probably available on the net.

 

[Agro]

Thank you. As far as I understand the sensor calibration service does not include sensor replacement. They say nothing about sensor replacement on their website - or I did not see it.