Q-7.1 NET RADIOMETER
8
recommends recalibration every six months,
depending on the climate where the sensors
are used.
Each instrument is calibrated by the
manufacturer in a temperature-controlled
calibration chamber by comparison to a
transfer standard. The chamber uses a
combination of tungsten-halide source and
black body chambers. The transfer standard is
calibrated by comparison to a precision
pyranometer using a partial shading technique
developed by Radiation Energy Balance
Systems. The long wave calibration of the
standard has also been verified using black
body chambers.
Care should, however, be taken when
comparing readings with sensors from different
manufacturers or even older models from
Radiation Energy Balance Systems. This is
because in recent years academic studies have
reported inadequacies both in the design and
calibration of net radiometers from most
manufacturers. Radiation Energy Balance
Systems aim to keep at the forefront of such
developments and have published corrections
for the calibration of older sensors. However,
these corrections cannot fully bring the
instruments to the same level of performance
as the new sensors. It is, however, possible to
upgrade and recalibrate the sensor heads of
older models.
Summary of Contents for Q-7.1
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