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
Robotic lawn mower mowers represented the second largest category of domestic robots used by the end of 2005. Possibly the first commercial robotic lawn mower was the MowBot, introduced and patented in 1969 and already showing many features of today's most popular products. In 2012, the growth of robotic lawn mower sales was 15 times that of the traditional styles. With the emergence of smart phones some robotic mowers have integrated features within custom apps to adjust settings or scheduled mowing times and frequency, as well as manually control the mower with a digital joystick. Modern robotic lawn mowers can contain specialized sensors,