Questions about the CO-Experts display

Hi George:

Question #1:

Please expand on the estimated COHb value:  does the unit have an integrating function where it adds up the various concentrations over time?

Question #2:

The “duration” feature confuses me … if the Peak value were say 60 ppm, but it only saw that for a few seconds, but there was say something like 10 to 59 ppm for 48 hours in the environment during the same incident, what would the “duration” say during the data recall?

Question #3:

The estimated COHb level concerns me a little bit … isn’t this in effect a medical diagnosis, that many would say is inappropriate for an HVAC guy or any non-medical professional to make?  This came up at a recent class.  How would you answer that?

Question #4:

If a unit says ERR, does it automatically need to be returned under warranty or thrown away if out of warranty?  Can we first suggest that they remove the battery, let it sit (for how long) then put the battery back in?


B. R.


Thank You, for your Questions.

COHb, has become a Very Controversial “Discussion” at several of our CSA – 6.19, CO Technical Committee Meetings, as well as in other Forums. It is my personal opinion “At this Time”, that while it is FAR for a Perfect Evaluation System, NO ONE has offered a BETTER PROVEN, “Evaluation Yardstick”. Obviously, when we KNOW that 100% CO can KILL you  , almost Instantly, … with Virtually NO Previous COHb factor, …. it is NOT Perfect.

That is EXACTLY WHY my monitor is Designed to Alarm / Warn “Instantly”, [ IDR Technology, “Instant Detection & Response” ], as well as TWA, instead of ONLY TWA, [COHb], [Time Weighted Averaging].

It is by Belief, [Opinion], that by COMBINING, BOTH of these approaches in my Monitor, I am Providing the “Best” of both Worlds of thought. IDR Protection for the “Occupant”, and COHb [TWA] for the Benefit on the Contractor, or First Responder.

Now for your Specific Questions:

1. Upon “Activation”, the “Time Clock” starts “Ticking”. My Monitors “TAKES & RECORDS” a New C O Reading every Ten Seconds, and the COHb Calculation also begins.
The Monitor compiles readings every 10 Seconds, for up to 999 Hours and 59 Minutes. Then it will continue to reflect the COHb, [once a CO Presence is detected], over the previous, [ LAST ], 999 Hours and 59 Minutes, … UNLESS, … the Data has been “Cleared” Electronically by Holding the “Test / Hush / Reset” Button Depressed for about 7 seconds, or until AFTER you have “Heard the Second Series of “Chirps”. Each and Every Time that you “Clear” the Data Electronically, the COHb Starts at Zero again.

2. The “Duration” reflects the “Period of Time” that the Level of CO Present at the Sensor was WITHIN 10%, of the “Peak”, [HIGH], C O Reading Recorded.
Frankly, I find this of Very Little Value, … UNLESS the CO Reading was fairly High. For example, at 20 ppm, … 10% is 2 ppm, and that degree of variation of C O Present in the Sensor at the next “Reading” is Very Likely.

3. In NO WAY should a Contractor, or even a First Responder, EVER be placed in a situation where they EVEN THINK that they are Responsible to make a Medical Decision. The WHOLE PURPOSE of designing the Low Level Monitor was to MAKE SURE that the people NEED NEVER be Exposed to Elevated COHb, … OR, … RAPID HIGH Levels of CO Exposure, … without IMMEDIATE WARNINGS.
The MOST IMPORTANT value of the COHb indication on my Monitor is realized in cases where Lower CO Levels are PRESENT in the Home, over a Longer Period of Time.
Especially over periods of time when No One was in the Home to hear the Earlier Warnings from the Monitor. By the Time a  Contractor, or First Responder enters a Home to do his “Testing”, the C O Level  previously Present, may have been Ventilated, at Least Reduced. If upon viewing the “Data Recall”, they see that the COHb indicated on the Monitor is,
let’s say, ” .05 “, … even though the Current C O in the house that they found was only 1 to 5 ppm, … THEY KNOW that there had been C O Present in the Home Previously to an Extent that Definitely Requires Further Investigation.
Especially, Sources that might be subject to regular Cycling.

When I teach a class on Portable Extinguishers, [or my Fire Aid One, Residential Fire Hose and Extinguisher Unit], … I always tell the Attendees: “If you look at the Fire, and have ANY DOUBT, that you CAN PUT it Out, … GET OUT, … don’t even try to extinguish it, .. JUST GET OUT. Likewise, you should tell your people, if at the 25 ppm warning, after you have opened your Doors & Windows, the CO Present Fails to Decline, … GET OUT, until Professionals have told them that it is SAFE to return.

4.  First, in NO CASE should you tell them to “Throw it away”.  Monitors can usually be repaired for $50.00.  Repaired / Re-Calibrated Monitors are given a New 12 Month Warranty.

Again, Thank You for your Questions,

Regards, ……………….. George



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