Why is a smoke bomb test not recommended for ionization duct smoke detectors?
Based on evidence with in-house and field-testing of ionization, duct-mounted smoke detectors, there are three notable reasons: 1. Ionization smoke detectors are most sensitive to smoke particles ranging from .01 to .3 microns. Particles produced by smoke bombs tend to become larger the farther they travel from the source, triggering a slow response. 2. Smoke bombs produce cold smoke particles, which are larger and not as easily detected by ionization smoke detectors. These particles are also dependent on relative humidity, distance traveled from the source and time of activation. This phenomenon is caused because the smoke is more of a mist than suspended solids in warm gases. In other words, the smoke doesn’t represent a true smoke composition or fire signature for smoke detector activation. 3. It is possible to pass a smoke bomb test, but to be out of the required manometer range for sampling, giving the installer a false sense of proper operation. Although unadvisable, if you choos
