Pyrgeometer IR02-TR

IR02-TR is a pyrgeometer suitable for longwave irradiance measurement in meteorological applications. The instrument can be heated, which improves measurement accuracy by mitigating dew and frost deposition on its window. IR02 houses a 4–20 mA transmitter for easy read-out by commonly used data loggers. IR02-TR measures the longwave or far-infrared radiation (FIR) received by a plane surface, in W/m², from a field of view angle of approximately 150 °. Longwave radiation is the portion of atmospheric radiation that is not emitted by the sun. While the actual field of view angle is not the ideal 180 °, the reduction makes it possible to offer IR02 at an attractive price level with only a minor loss in accuracy. IR02 has a window with a cut-on at 4.5 x 10⁻⁶ m, making it suitable for both day and night observations. Operation Using IR02-TR is easy. It connects directly to commonly used data logging systems. The irradiance in W/m² is calculated by using the transmitter’s output and temperature reading. The final result is calculated by 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, which can be adjusted at the factory upon request. IR02-TR employs a thermal sensor with black coating, a flat silicon window with a solar-blind filter, and an anodized aluminum body. Its built-in on-board heater prevents condensation on the pyrgeometer window, which can otherwise cause significant measurement errors.