Integrator and sensors for measuring photosynthetically active radiation and temperature in the field.
Designs are described for sensors, integrators and a readout device which together measure temp. (or day-degrees) and photosynthetically active radiation (or short-wave radiation in the 300-3000 nm waveband). The equipment is cheap to produce ( pounds-sterling 15-18) and has a low electrical power requirement (3 mW at 20 deg C). The integrators may be adjusted to measure temp. or irradiance above set thresholds.