CO-Experts Low Level Monitor use in aircraft


Aeromedix is selling your model 2002 for use in aircraft cockpits.
This environment is not “air conditioned”. Temperature and humidity are close to what’s outdoors, until we’re in cruise and the cabin heater begins to catch up.
I happened to look at the Figaro TGS 2442 specs, and it is extremely sensitive to both temperature and humidity.
So my question is: is your unit compensated for temperature and RH?



Dear Rod,

Thank You, for your Question. The “Sensor Technology” offered by Figaro IS very sensitive to changes in Temp. & Humidity; however, Figaro is VERY Honest about this problem, and DO offer a Special IC Chip to provide a “Fairly Good” Degree of Compensation.
The “Real Life” problem is that this IC Chip is Quite Expensive, and MOST Detector / Alarm manufacturers choose to try to “Tweak” their own process instead. This usually results in a VERY Un-Stable products. Much MORE Sensitive in High Humidity, … FAR Less Sensitive in Low Humidity.
Another Sensor Technology used in CO Detection called: “ColorMetric”, or “Chemi-Optic” is effected in a Similar fashion.
The Sensor that I use in my Monitor is a LARGE Volume, “Acid-Based”, Electrochemical Sensor that is Virtually Un-affected by changes in Temp. or Humidity changes that you are ever “Likely” to encounter.
The Sensor will not “Freeze” until about Minus 55 C, and High Humidity can actually Increase the “Life” of this type of sensor.
“IF”, this type of Sensor was subjected to ” 0 ” Humidity, and VERY HOT Temperatures for a Long Period of Time, … CONTINUOUSLY at “0” Humidity, … IT WOULD,  “EVENTUALLY” … “Dry-Up’ the Electrolyte inside the Sensor, causing the unit to go into a “Sensor End” Warning on the Digital Display, and emitting a “Chirp” and a Flashing RED, … LED.
The reason that I feel Confident that such a “Drying Out” process WILL NOT occur in less than 6 to 9 years, is that the Sensor will “Replenish any “Lost” moisture, as soon as the Humidity around it is increased from Any Source. [Rain, Steam, Fog, etc.]
The Most Important Feature, of the Many that are offered by my Monitor,…. is the FACT that ALL of the Primary Components ARE FULLY MONITORED, Including the SENSOR.

My Monitor WILL FAIL Someday; however, When it does, … YOU WILL KNOW IT  ! ! !
I suggest that from Time to Time, you check my Website at:

Best Regards, ……………………. George E. Kerr
Dear George

It was a pleasure talking to you on the phone the other day.  We are all indebted to you for your persistence in making available a detector so sensitive and accurate as this one.

We carry it in the airplane when flying and into the motel or hotel on the ground to keep us safe at all times when traveling.  At home it sits on the kitchen counter.

D. R. (pilot in Howell, Michigan)
George, I am using it in my flight bag, will putting it in a Ziploc bag when not in use extend the sensor life? – tnx


No storing your Monitor in a Ziplock Bag, will not extend the “Sensor Life”.

The “Useful’ Life of the Sensor is 5 years, unless it has been  Repeatedly Exposed to Excessively High CO Concentrations, or left in an Extremely Hot, Very Low Humidity, Environment Continuously for a long period of time.

Thank You, for your question, and keep “Checking” my Website at:
your “Total Source” for C O Info.

Best Regards, ……………………. George

Dear Mr. Kerr:

I enjoyed speaking with you on the phone last week.  After our discussion I ordered two units.

I just opened the two CO Experts low level CO Health monitors received from you. (Invoice #002261)

In reading through the literature I notice the caution stating they are not to be installed anywhere that the temperature might exceed 100 degrees Fahrenheit or go below 32 degrees Fahrenheit for more than a 24 hour period.

That raises a concern for me in that I intended to place one of the units in an airplane which lives most of its life on a covered tie-down.  The shade of the cover allows the plane’s interior to closely match the outside ambient air temperature… albeit lagging a little.  Unfortunately in the Phoenix , AZ area that might be 100-115 degrees for as long as 10-12 hours of the day. That plane also occasionally goes to the mountains in the winter for skiing and is exposed to below-freezing temperatures.

Obviously the time above 100 degrees is not a full 24 hours and the time below freezing may or may not be a full 24 hours. However, I wonder if continuous cyclic exposure will shorten the useful life, or alter the accuracy of the unit.

Were I to use this device in a car, I would encounter the same problem.

Please advise me if my concern for frequent cyclic exposures of less than 24 hours is warranted. What detriment occurs to the unit if subjected to those temperature extremes for 24hours or more? Must I (or would I be wise to) remove the unit from the plane when it is parked.

Gratefully yours,



Thank You, for your question, it is one that comes up often from pilots, hunters and campers.

The “normal operating temperatures” listed in the manual are what we consider “normal, ideal, residential temperatures” which produce the very best “accuracy results” from the sensor. As you can see from the following “Link” to the specification sheet from my sensor manufacturer, the “Storage Range” temperatures for the sensor when in an unoccupied environment is a much broader -40 C, to +70 C.

In repeated accuracy tests at colder temperatures down to -20 C we found that the “sensor activity”, thus the percentage of retained accuracy to our original calibration scale, was decreased less than 10%. An “Acid Based” Electrochemical Sensor like the one I use reacts very similar to a car battery, producing a little less “power” when very cold, and also like a car battery, will experience a return to normal performance as the temperature returns to a more normal “lived in” environment room temperature”.

Frankly, I believe that you will find that the temperature extremes will have far more negative effect on the battery “life”, than the sensor “life”.

Please refer your friends and family to my Website for all of their C  O questions.

Best Regards,
George E. Kerr, President / Founder
C  O – Experts


I would like to thank you for your CO-Experts monitor.  Our detectors recently sounded their alarm, and we called the gas company who confirmed the same readings as your monitor.  Our furnace had a cracked heat exchanger which triggered the alarm.  I am interested in a CO monitor for marine use on my boat and was told you were developing on that would perform well in a corrosive environment.  Any update as to availability?


Thanks for your note.  We are happy our CO-Experts Model 2002 worked well for you.  A unit for a corrosive marine environment is so expensive to produce that it is best to use our normal unit and accept the shorter-than-normal useful life.  We thing that buying a $100 detector and replacing it every few years is more economical than buying a high-priced device.

Brent Blue, M.D.
Hello George,

I tried to find this comparison on your website. I am a pilot and have used the model 2002 for a couple years now. Sometimes it seems too sensitive. Could you please offer an explanation of the differences in the models and why? Thanks in advance.

The Model 2002 displays from 5 PPM to 70, then “HI”, with first audible alarm at 10 PPM.  The audible warnings are at 10, 25, 50 & 70. [Recalled “HI” is displayed from 1 PPM up].  The “Stored Data” time of “Occurrence” and “Duration” is given in hours & minutes, and if not cleared, this data remains in the Monitors memory for 42 days.

The Model 2004 displays from 10 PPM to 70 PPM, then “HI”, with first audible warning at 25 PPM.  The audible warnings are at 25, 35, 50 & 70 PPM. [Recalled “HI” is displayed from 10 PPM up].  The “Stored Data” time of “Occurrence” and “Duration” is given in days, hours & minutes, and if not cleared, the data remains in the memory for 2 years and 8 months.

The Model 2002 caused a LOT of consumer confusion because of retained high readings from 1 to 9 PPM, even though the instructions clearly say that NO ACTION is REQUIRED until it reaches 10 PPM. Unfortunately, in some areas of our Nation, the Outdoor AIR has become so polluted that the ambient CO exceeds the 10 PPM initial alarm level of the Model 2002, leading to constant alarms.

Thank You, for your questions & comments,
George E. Kerr, President / Founder
C  O – Experts


Back to “Ask an Expert”         Back to the “Aircraft” Section           Return to Main Page



CO Experts
19299 Katrina Lane; Eldridge Missouri 65463-9102
Tel: 1-888-443-5377 Fax: 1-888-436-5377