Yes they do. That never appears in ads for them and the state legislatures that force them to be in every home don't seem aware of that. Most are dead after seven years. Some go in three to five. When they reach what the manufacturers call "end of life" they do a beep pattern that sound like that for a weak battery. I had to bring my alarm to the fire station to get them to confirm end-of-life after I changed the batteries twice and both sets of new batteries still made it beep like that. Some manufacturer's websites tell about it. First Alert has a note in their printed instructions that says they "have a limited life."
My state passed a CO alarm law seven years ago and right on schedule (but at 2 AM) mine went to end-of-life at that time. Thousands of people are in for a big surprise when their alarms start doing that.
answered 4 months, 3 weeks ago
The promo states the unit will let you know when it's life is over and it needs to be replaced.
NO. Should last indefinitely, although the batteries have to be replaced each year. (The unit actually beeps when the batteries get low, but I would'nt rely on this--just put the battery change date in your calendar). Batteries are easy to change.
answered 2 years, 9 months ago
- Livingston, CA
The packaging doesn't answer this question but does indicate that dust can cause it to no longer work so suggests not to place in dusty areas.
answered 2 years, 11 months ago
Not that I am aware of, I did have one before I bought this one a few months ago and the only reason I replaced it was I dropped it while moving and it got stamped on, so It broke into make pieces. I had my previous one for about 6years and my mother has never changed hers, she has had it for many years more!!
answered 3 years, 6 months ago
- Newark, NJ
The basic components of an electrochemical sensor are a working (or sensing) electrode, a counter electrode and usually a reference electrode as well. These electrodes are enclosed in the sensor housing in contact with a liquid electrolyte. The working electrode is on the inner face of a Teflon membrane that is porous to gas, but impermeable to the electrolyte.
The gas diffuses into the sensor and through the membrane to the working electrode. When the gas reaches the working electrode, an electrochemical reaction occurs; either an oxidation or reduction depending on the type of gas. For example, carbon monoxide may be oxidized to carbon dioxide, or oxygen may be reduced to water. An oxidation reaction results in the flow of electrons from the working electrode to the counter electrode through the external circuit; and conversely a reduction reaction results in flow of electrons from the counter electrode to the working electrode. This flow of electrons constitutes an electric current, which is proportional to the gas concentration. The electronics in the instrument detects and amplifies the current and scales the output according to the calibration. The instrument then displays the gas concentration in, for example, parts per million (PPM) for toxic gas sensors and percent volume for oxygen sensors. Thus, the electrolyte is consumed over time and exposure to CO and will need to be replaced. Solid state detectors are able to last for many years but consume too much power to be battery operated. See: http://www.indsci.com/training_details.aspx?id=1552 for more information.
answered 3 years, 10 months ago