IR02-TR is a pyrgeometer suitable for longwave irradiance measurement in meteorological applications. The instrument can be heated, which improves measurement accuracy as it prevents dew deposition on its window. IR02-TR houses a 4-20 mA transmitter for easy read-out by dataloggers commonly used in the industry.

IR02-TR measures the longwave or far-infra-red radiation received by a plane surface, in W/m², from a field of view angle of approximately 150 ^o. Longwave radiation is the part of radiation that is not emitted by the sun. The actual field of view angle of IR02-TR is not the ideal 180^o. The reduction of this field of view makes it possible to offer an instrument at an attractive price level, while the accuracy loss is relatively small. IR02-TR has a window with a cut-on at 4.5 x 10^-6 m, making it suitable for day- and night observations.

Using IR02-TR is easy. The pyrgeometer can be connected directly to commonly used data logging systems. The irradiance in W/m² is calculated by using the transmitter’s output and the temperature reading. The final result is calculated taking into account the irradiance radiated by the sensor itself (Stefan-Boltzmann law). In IR02-TR’s standard configuration, the 4 to 20 mA output corresponds to a transmitted range of -300 to +100 W/m². This range can be adjusted at the factory upon request.