American Ramsay Ramsay DTR131 microwave traffic detectors (Thermo Ramsey) DTR131 DTR131 microwave traffic detection using the Doppler effect is a non-contact microwave motion detectors. DTR131 different frequencies can be measured between the transmitter and the reflected microwave microwave. Can change the received microwave energy (e.g., due to the accumulation of material with the antenna before) has no effect on the material flow / stream without detection. Detection range: 0-5 feet (depending on the application) Operating Frequency (Microwave): 24.124GHz Maximum working pressure: 15psi Ambient temperature: -20 ~ 60 ℃ sensor surface maximum temperature: 80 ℃ Supply voltage: 220VAC/50Hz relay output contacts: 4A/500VA/250V switching delay: 2-10 seconds Case Material: Aluminum Explosion-Proof: FM approved, dust, fire Ⅱ grade, Div.1, GrpsE-G