Alarm Operating Temperatures

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

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