Testo 330-1

[Midwest]

I have a Testo 330-1 that seems to eat CO sensor cells. Anyone have similar problems. The highest reading the last cell encountered was 3100 ppm. A high CO warning alarmed and it was removed immediately. After that, the CO would not work until a new cell was installed. They're supposed to be good for 5000 ppm. The first cell replacement came after about 0.9 hours of use according to the isntrument's recall. That's not much time of general exposure in my opinion and the instrument wasn't exposed to high ppm readings whatsoever that time. Testo isn't any help, except to advise me to 'order a new cell'. It just seems to me that 0.9 hrs isn't much exposure and a one time hit of 3100 ppm shouldn't kill a sensor cell. Any advice? At $230/sensor and a sensor every couple of months (I'm not even using it that often) this thing needs to be tossed so I can cut my losses.

[jim bergmann]

There is a protection feature in the settings to shut off the pump when a predetermined CO level is reached. Set it at 1000 ppm and that should curtail the problem. If your burner is producing over 400 ppm something is really wrong anyway. Additionally, if you encounter high CO, disconnect the probe from the meter and let it purge until the CO goes back to 0 ppm. The pump will shut off, but what is in the hose can still over range the sensor.

I also set mine up to show stack temp, CO, COAF and O2 on the first screen so I do not accidentally over range while on another screen.

If you need to contact me via PM, look at my profile and give me a number to call you.

Jim Bergmann
HVAC/R Technical Specialist
Testo Inc.