When used in the NRM configuration, (measuring Net Radiation only), the four mV outputs should
be connected as indicated by the line on the right side of the drawing, creating one single output. In
this case the lower sensors are electrically connected in anti-series with the upper sensors because
the signals of these sensors must be subtracted from the signals of the upper sensors. In the NRM
configuration, the Pt-100 signal is not essential. All connections should be soldered. In the 4SCM
configuration, (measuring two Solar Radiation signals, two Far Infrared signals and, for
calculation purposes one Pt-100 signal) all signals are measured separately, and the calculation
of Net-Radiation and albedo are ultimately performed by the instrument
user's own processing software. The sensitivities of the individual sensors are adjusted to the same
sensitivity, using the trimming resistors. The resulting sensitivity is indicated on the side of the
CNR 1 's casing. The heater should only be used if a power supply is not a problem, to eliminate
dew and frost deposition. It is not a necessity, and will introduce some measurement errors. Under
most conditions the accuracy that is gained by heating will be larger than the errors that are
introduced by heating. It runs on 12 VDC, 6 VA for dew prevention. Generally, it is suggested to
heat only at night.