Gas detector in industrial refrigeration processes and biological degradation processes, including exhaled breath. Depending on the required sensitivity, different types of sensors are used (e.g., flame ionization detector, semiconductor, electrochemical, photonic membranes). Detectors usually operate near the lower exposure limit of 25ppm; however, ammonia detection for industrial safety requires continuous monitoring above the fatal exposure limit of 0.1%. There are several different sensors that can be installed to detect hazardous gases in a residence. Carbon monoxide is a very dangerous, but odorless, colorless gas, making it difficult for humans to detect. Carbon monoxide detectors can be purchased for around US$20–60. Many local
Lawn mower measured between 86-95 decibels (A-weighted) and from riding lawn mowers between 88 and 96 dB(A); both types exceeded the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit of 85 dB(A). To reduce the possibility of developing hearing loss and reduce noise pollution, users might consider the use of reel mowers or newer "green" or battery-operated mowers. Appropriate hearing protection such as earplugs or earmuffs will also help reduce the amount of sound that the user hears, which in turn can reduce hearing loss caused by lawnmowers. Lawn mower A lawn mower (also named as mower or lawnmower)