Valuable information! Thanks! Our LP detector also didn't go off when we had a gas leak at the stove. I was in the unit all day and didn't notice, I guess because I got used to it? I'm normally very sensitive to smells. But when my husband got home from work and opened the door he noticed it immediately! And so did anyone else coming in.
This special spray to test for propane that you write about - where can one buy it? Is there any way to test the CO detector? I somehow thought that the test button was to see if the detectors were operating, now it sounds to me as though the buttons only test that the battery is still okay.
- Lorna
You test a CO detector with Carbon Monoxide. Don't take it to the exhaust pipe of the truck and try it there because you'll only ruin it. Normally, a certified concentration of the gas is used to be sure it sets off at the lowest level. Heating companies normally have the stuff to test them.
In regards to the LP smell, your nose is highly sensitive to the mercaptan odorant they put in it, same as natural gas in the home. The level you can smell it is below the level the LP detector will detect actual flammable gas.
This is some general info on when CO detectors will alert:
The alarm points on carbon monoxide detectors are not a simple alarm level (as in smoke detectors) but are a concentration-time function. At lower concentrations (e.g. 100 parts per million) the detector will not sound an alarm for many tens of minutes. At 400 parts per million (PPM), the alarm will sound within a few minutes. This concentration-time function is intended to mimic the uptake of carbon monoxide in the body while also preventing false alarms due to relatively common sources of carbon monoxide such as cigarette smoke.
This is an example of the detector sensitivity of an LP detector:
ALARM TRIGGER < 25% of the LEL of Propane and Methane
What does this mean? LEL means lower explosive limit. Propane and methane are similar to natural gas. The explosive range for them is 5 - 15% concentration in air. Above 15%, or below 5%, and nothing happens (other than maybe oxygen deficiency, another matter). In the range, a spark can set it off...KABOOM! Now, 5% is the same as 50,000 parts per million. 25% of that is 12,500 ppm. The detector may actually start to sound below that concentration. So, unless you have a large leak filling the room quickly, you will have a large window of safety to get out, shut off the tanks, and air out the place.
This is some info on the methyl mercaptan odorant: "The threshold for human detection is as low as one part in 2.8 billion parts of air." That's parts per billion, not parts per million. A huge difference.
Be cautious and alert, but don't get paranoid about it. Just because you smell it inside does not mean you're in eminent danger. It does mean you need to check your propane system and appliances for possible leaks or stove knobs knocked askew. If you smell it for a period of time and then it fades away, then you may be getting desensitized to it and you've got a problem if you haven't checked things out.
After posting the above, I remembered that you were running off an external 100 lb. propane tank. Try checking around the connections between it and the rig, as well as the lines running along the frame rail. A loose fitting or nicked hose outside may be releasing just enough gas that you're getting the smell inside.
