Campbell Scientific CNR1 Net Radiometer - Manual (Page 5)

CNR1 Net Radiometer
1. General Description
The CNR1 Net Radiometer is intended for the analysis of the radiation balance
of Solar and Far Infrared radiation. The most common application is the
measurement of Net (total) Radiation at the earth's surface.
The CNR1 design is such that both the upward-facing and the downward-
facing instruments measure the energy that is received from the whole
hemisphere (180 degrees field of view). The output is expressed in Watts per
square meter. The total spectral range that is measured is roughly from 0.3 to
50 micrometers. This spectral range covers both the Solar Radiation, 0.3 to 3
micrometers, and the Far Infrared radiation, 5 to 50 micrometers.
The design of CNR1 is such that Solar radiation and Far Infrared radiation are
measured separately. Solar radiation is measured by two CM3 pyranometers,
one for measuring incoming solar radiation from the sky, and the other, which
faces downward, for measuring the reflected Solar radiation. From these two
pyranometers, albedo, the ratio of reflected and incoming radiation, can also be
determined. Far Infrared radiation is measured by two CG3 pyrgeometers, one
for measuring the Far Infrared radiation from the sky, the other from the soil
surface.
An incorporated heater allows the CNR1 to be heated to prevent dew or frost
accumulation on the sensors.
Additional information on the CNR1 sensor can be found in the Kipp & Zonen
CNR1 Manual. The primary intent of this manual is to provide information on
interfacing the CNR1 to Campbell Scientific dataloggers.
2. Sensor Specifications
2.1 CNR1 Specifications
See the Kipp & Zonen manual for additional specifications.
Sensor sensitivities: All four sensors have equal sensitivity
Pt-100 sensor temperature
measurement:
DIN class A
Expected accuracy of the
temperature measurement:
± 2 K, under non-stable conditions
with solar heating or heating by using
the heating resistor.
Operating temperature: -40 to +70 degrees Celsius
Requirements for data acquisition:
Radiation components: 4 differential or 4 single-ended analog
channels
Pt-100 temperature: 1 excitation and 2 differential analog
channels
Expected accuracy for daily totals: ± 10 %
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