"The MS - 402 pyranometer is a unique ISO first class pyranometer and best in its category. As the only first class sensor available on the market it has a built in electronic passive temperature compensating to linearize the detector temperature coefficient and make it accurate under all temperature conditions. The design of the MS - 402 first class pyranometer is very similar to the secondary standard MS - 802. It's robust brass mechanical construction makes it a durable sensor suitable to be used in harsh environments for routine global irradiance measurments. The MS - 402 can be applied as multi purpose high quality monitoring sensor in the PV and meteorological market. MS - 402F is a MS - 402 with 110VAC\/12 VDC ventilation system to prevent any possible influince of frost, snow and dust.","• Most Accurate First Class Pyranometer • Response Time (95% < 8s) • Temperature Compensated <1% (For 50°C Band) • Near Secondary Standard Specifications"