UVB-1 Pyranometer (broadband)
UVB-1 Pyranometer (broadband)

The UVB-1 Pyranometer, manufactured by Yankee Environmental Systems, measures global irradiance in the UVB spectral range of 280-320 nm. The measurement technique employs a combination of colored glass optical filters to block the Sun's visible spectra and a UV sensitive fluorescent phosphor to convert the UVB light o green light which is then measured with a solid-state GaAsP photodiode. The UVB-1 is environmentally sealed and thermally stabilized at ~45°C. Signal output is 0-4 volts DC, low impedance, corresponding to 0-7.88 Watts/meter2 of effective UVB irradiance. This measurement is converted into erythemal-weighted units, i.e., that part of the UVB spectrum responsible for sunburn on human skin (erythema) and DNA damage.

This instrument is cycled through NOAA’s calibration facility at Mauna Loa to update its calibration periodically. The calibration information for each UVB-1 pyranometer can be found under the Location Information, Deployment History.

The UVB-1 instrument is connected to the vis-MFRSR datalogger, so its output is measured every 15 seconds and integrated into 3-minute averages, and its data is retrieved nightly in conjunction with the polling of the vis-MFRSR datalogger. When the USDA was developing its concept for the UVMRP program in the early 1990's (Gibson, et al., 1998), this and other types of broadband instruments were all that was available to measure the UV irradiance. The UVMRP has retained these instruments since the inception of the project to maintain a continuous record of UV measurements, and also because many other researchers around the world use these broadband-type instruments, which enables more direct comparison of their data with the UVMRP data.