pyranometern.

1916 Abbot & Aldrich in Smithsonian Misc. Coll. 66 No. 7. 2 The name Pyranometer, selected for the instrument we have devised, is taken from Greek words (πῦρ, fire; ἀνά, up; μέτρον, a measure) signifying that which measures heat above. The name was chosen with reference to the fact that the instrument is designed to measure the energy of radiation to or from a complete hemisphere lying above the measuring surface.

1967 Jrnl. Appl. Meteorol. 6 688 (heading) An integrating pyranometer for climatological observer stations and mesoscale networks.

1973 Nature 16 Feb. 448/2 These data were obtained by subtracting the solar radiation measured by a temperature compensated Eppley pyranometer from the mean hemispherical all-wave radiation obtained from three Fritschen-type net radiometers converted to hemispherical operation.

2005 Daily Tel. 22 June 34/5 It doesn't even end once you've made a reading with your pyranometer (which..are apparently the most common instrument used to measure solar radiation).

1938 Q. Jrnl. Royal Meteorol. Soc. 64 465 The pyranometric error,..responsible for the large variation of the solar constant observed during 1928.

1995 Arctic & Alpine Res. 27 383/1 Values were corrected for variations of I_a(λ) using 10-min averages of pyranometric measurements.