Madison Company”sO Series optical single-point, liquid-level detection switches aredesigned for use in noncoating liquids. The units provide accurate,repeatable switching-point detection with no moving parts. They operatewith a phototransistor that provides a digital output indicating thepresence or absence of liquid. The phototransistor is housed in thesensor tip, providing highly reliable performance in a compact design that is a good fit for applications wherespace is limited. Over 70 standard models are available, with bothmetal and plastic housings and various mounting configurations, as well as wire- and supply-current options. All are designed for easy installation and maintenance-free performance. Custom-engineered designs may also be requested by using Madison”s O Series specification sheet, available on the company”s Web site at