NR Lite2 - Net Radiometer
NR Lite2 is designed to measure total radiation, which represents the balance between incoming and outgoing radiation in the outdoor environment.
Difference between CNR4 and NR Lite2 radiometers
Both devices use thermocouples, but the dome above the thermocouple determines what type of radiation passes through and reaches the thermocouple. The thermocouple is usually protected by a single or double dome to reduce deviations caused by sudden temperature changes such as wind.
The CNR4 net radiometer uses two glass domes to cover the pyranometer and two silicon domes to cover the pyrgeometers. It uses two thermoelectric detectors (1 for each of the two pyranometers and 1 for each of the two pyrgeometers) and provides two separate outputs. One for short waves (solar spectrum having a bandwidth of 300 nm to 2800 nm) and one for long wave radiation (long wave infrared spectrum having a bandwidth from 4500 nm to 42000 nm). This leaves a gap between 2800 nm and 4500 nm. This is the so-called atmospheric window, into which very little radiation enters (see picture below).
The NR Lite2 net radiometer is not protected by domes and is in direct contact with weather conditions. Due to the wind, it can therefore cool much more significantly, which affects the accuracy of the measurement. The NR Lite2 does not use a glass or silicon cover but has two PTFE coated detectors and provides a single output for shortwave and longwave radiation. It uses one thermocouple to measure the full spectrum of far infrared and solar radiation. The PTFE thermocouple cover transmits a band from 200 nm up to 100,000 nm.
Note:
As mentioned, the NR Lite2 is wind sensitive. The correction can theoretically be performed by multiplying the calculated radiation by a factor (1 + x • v¾), where v is the wind speed in m/s and x is determined empirically - approximately 0.01.
Connection of signal cable terminals:
red: + voltage signal
black: - voltage signal
shielding
Technical parameters
Spectral range (for 50% decrease): 0.2 to 100 µm
Rise time (for 63% of final value): <20 s
Sensitivity (typical): 10 µV/W/m2
Directional sensitivity (up to 60º): <3%
Sensor asymmetry (upper/lower): <15%
Documentation
Download
Application
no related solutions