FD-90A-CO

As an HVAC technician, I always check my customer's equipment to ensure they are not in danger of CO poisoning. I use a Forensics Detectors Professional Combustion Analyzer as well as this handy tool to check room air for any possibility of CO production or leakage from combustion appliances. I find this model very handy, and keep it turned on and clipped to my service bag while I'm working in the customers home. I'm glad I discovered Forensics Detectors, their products are great quality, easy to use, and are cost effective.

I purchased this in December 2025. It detects carbon monoxide spilling from hot water heater back draft in under 1 minute and alerts with visual and audible alarm volume at 70 dB. You can set the device as low as 1ppm. It is a low-level detector that doesn't take up to 4 hours to alert at 70 ppm like regular home CO detectors, however it is not a substitute for those but rather complimentary. It is rugged and professional quality construction, suitable for travel as well. I believe it can be carried on an aircraft. It came with a certificate of calibration.

Less than 3yrs, and it will no longer read co. Probably used 10 times. Don't know how the life of the sensor compares to others, but this seems a short life.

This is the second Forensics CO meter we have purchased. The first one is used in our Sprinter van as the primary CO sensor in case something goes wrong with the diesel "parking" heater. It responds much more quickly to CO level changes compared to standard consumer-grade household detectors, and instills far more confidence in its detection and alarm capabilities than the latter. For that reason we have purchased this second unit for our house, and plan to use it for continuous monitoring just in case something goes amiss with the gas furnace (there still are 4 household CO sensors in place as backups). Definitely satisfied with this CO detector, and plan to get a third one next year as a gift for our daughter's house.

I wish the description would have included: a. this needs to be recalibrated every 6 months with testing equipment I don’t have, b. it will last only 2-3 years, and c. it is not intended for constant use. I did not discover these points until I opened the box and read the instructions.

Bought to measure CO emissions from my vent-free, propane-fired gas log set. After measuring zero, I called the mfgr to get testing method for the meter and yup, it works fine. Log set is burning clean. Will use it to test other propane heaters in my garage and hoop-house.

I need an accurate and sensitive CO detector to see if my gas furnace leaks CO into the house. After posting a question on whether it is accurate enough for my purposes. An engineer from the company contacted me on the same day and explained to me in detail. After that, I bought one and put it to test. The outdoor exhaust pipe reading was 11 ppm, comparable to the one recorded by an HVAC company a year before. The indoor reading was 0, indicating no CO leakage. The device is easy to use. It is sensitive and appears to be accurate. I am very please with it. The company is very responsive and helpful. I will be able to use it this coming winter to test for CO, when in doubt. Home CO alarms are meant for spikes only, in my opinion. Small leaks are better tested with this device. After 6 2-minute readings, the battery is only down by 3%. Thank you, Forensics.

This unit must be calibrated to be of value. To calibrate you can: 1) send it to the vendor - cost $75 plus one-way shipping, 2) Buy calibration gas - $140 plus $99 for a gas regulator (pressure/flow valve) for a total of $239. I suppose all such units should be calibrated, but paying $239 to calibrate a $89 item seems excessive. I guess you will have to determine if your life is worth $239. In any case, the calibration requirement should have been highlighted in the display write up. The unit does appear to be well built.