CO meter vs. CO alarm

[branchburner]

Was thinking about a second CO detector, but wondering if anyone knows a brand that gives low-level readouts without an alarm sounding. Seems most show nothing under 30ppm, and don't alarm until an extended period of higher exposures to avoid "false" alarms (which could of course mean chronic exposure to low levels).

The other way to go would be to get an actual meter for $100 (or two) that will show exact levels, even as low as a few ppm. Of course I could get one of each, but is there perhaps a hybrid version that's not too expensive? It seems a CO monitor can NOT get a UL listing if it does the "disservice" of letting people know about any possible chronic exposure to low-level CO in their homes.

 

[webbie]

I think mine has a digital readout on it which starts at 0 (zero).....

Something like this:
http://www.homesafetymatters.com/COALARM11?gclid=CNT_xeT3g7sCFcQDOgodrRQAtg

 

[firefighterjake]

Webbie . . . does that model actually show any readings lower than the 30 ppm threshold? I know some Nighthawk/Kidde models have readings, but only show the numbers if they are higher than 30 ppm.

 

[BrotherBart]

I have the Nighthawks. They don't display normally below thirty unless you push a button and then it shows the last highest reading under thirty.

I push the button on the one in the kitchen sometimes just walking by. Got a surprise a couple of years ago when I had been burning the stove low with the range hood fan running for a long time on a rainy weird atmospheric pressure day.

 

[webbie]

Mine says PPM next to the zero - and I think it reads PPM serially. I'll test it next to the gas stove!

 

[webbie]

Yes, it only displays starting at 30 - alarm, I think, starts at 400.

The question becomes if "low level" CO means anything much? Would a bit of nail polish or solvent or outgassing of building materials set it off? My assumption is that it will, and therefore these are set to avoid driving people crazy....

Levels of 5 to 15 PPM are said to be normal near a gas kitchen range.....

 

[Seanm]

Webbie . . . does that model actually show any readings lower than the 30 ppm threshold? I know some Nighthawk/Kidde models have readings, but only show the numbers if they are higher than 30 ppm.

I have this one http://www.kiddecanada.com/utcfs/Templates/Pages/Template-53/0,8062,pageId=2732&siteId=463,00.html but it doesn't say how low of a reading it has only says that you should press the button and it will give you the highest recorded reading. Mine said 0 but does it mean 0 or 30 or 40? Now im questioning it myself. On the back it says alarm response time 400 ppm within 4-15 minutes but based on the above comments I must be interpreting that wrong.

 

[branchburner]

Would a bit of nail polish or solvent or outgassing of building materials set it off? My assumption is that it will, and therefore these are set to avoid driving people crazy....

Yes, the point of these alarms is to prevent acute and potentially fatal poisoning at levels in the 100s of ppm. But many of the alarms note they will not serve the purpose of monitoring chronic toxicity that results from 10-30 ppm, a potentially serious problem especially for pregnant women. That means they are useless if your furnace is only a "little" faulty rather than fatally faulty.

 

[mellow]

Found this interesting about my Kiddie CO with digital readout:

In accordance with UL 2034, the CO sensor will not alarm to levels of CO below 30 ppm and will alarm in the following time range when exposed to the corresponding levels of CO.

70 ppm CO concentration 60 – 240 minutes
150 ppm CO concentration 10 – 50 minutes
400 ppm CO concentration 4 – 15 minutes

 

[branchburner]

the CO sensor will not alarm to levels of CO below 30 ppm

And that makes sense, because you would get a lot of nuisance alarms otherwise... but it would also make sense if the CO sensor gave you visual readings below 30 ppm without any alarm sounding.

 

[mellow]

Very interesting read about that UL 2034:

Obviously, a product which says that it is designed to protect “Young, Healthy Adults” while further pointing out in the Liability Disclaimers on all UL-2034 Listed & Labeled C O alarms verifying that they WILL NOT properly protect Millions of our Nation’s most venerable Citizens such as those listed below, including, but not limited to the fetus, pregnant women, infants, young children, the Elderly and all those affected by many serious illnesses or diseases.

A Kidde-Nighthawk Model #KN-COPP-3 says: "Pregnant women, infants, children, senior citizens, persons with heart or respiratory problems and smokers may experience symptoms at lower levels of exposure than noted. Individuals with medical problems may consider using warning devices which provide audible and visual signals for carbon monoxide concentrations under 30ppm.

PRO-TECH and their parent company S-Tech; as well as many other UL-2034 Listed C O alarm manufacturers say: “Individuals with medical problems may consider using warning devices which provide audible and visual signals for carbon monoxide concentrations under 30ppm

The is clearly stated in the UL-2034 Standard’s “Scope” of C O PPM levels at which Testing “IS” and “IS NOT” Required, and which of our Citizens such a C O Standard “Does and Does Not” PROTECT.”

"Clearly marked on Every UL / CSA C O alarm, directly under the “effects of C O exposure chart” is the statement that: ….. “these products are made to PROTECT “Young, Healthy Adults”.

(broken link removed to http://www.coexperts.com/Unconstitutional.htm)

 

[mellow]

http://www.amazon.com/Ultra-Level-Carbon-Monoxide-Detector/dp/B00BTK3M46/ref=cm_cr_pr_product_top <-- out of stock
http://www.aeromedix.com/Ultra-Low-Level-CO-Detector-CO-Experts-2014.html <-- same but maybe in stock? Pricey.

(broken link removed to http://www.defenderdetectors.com/ll6070.html) <-- no pricing found

 

[mellow]

Thanks for bringing this up, I had no idea about this, done quite a bit of reading and learned a thing or two about how sometimes UL listing isn't the best thing for everyone.

 

[branchburner]

I imagine the fire departments and HVAC guys and others use something like these:

http://www.amazon.com/UEi-Test-Instruments-CO71A-Monoxide/dp/B000MMFAAQ

http://www.amazon.com/Meters-PCMM05-Carbon-Monoxide-Meter/dp/B005FU5J5Q