CNR4
CNR4
Orderable4-Component Net Radiometer
Overview
The CNR4, manufactured by Kipp & Zonen and cabled for use with Campbell Scientific data loggers, is a research-grade net radiometer that measures the energy balance between incoming and outgoing radiation. Our data loggers measure the CNR4's output. This net radiometer offers a professional solution for scientific-grade energy balance studies.
Key Advantages
Four-way, research-quality radiometer; thermistor and Pt-100 built in
Technical Description
The CNR4 consists of a pyranometer and pyrgeometer pair that faces upward and a complementary pair that faces downward. The pyranometers and pyrgeometers measure shortwave and long-wave infrared radiation, respectively.
The upper long-wave detector of the CNR4 has a meniscus dome that allows water droplets to easily roll off of it. The dome shape also increases the field of view to nearly 180° instead of 150° for a flat window.
The CNR4 contains both an internal thermistor and an internal Pt-100 RTD. Typically, the thermistor makes the instrument housing temperature measurements used to compensate the infrared readings. Alternatively, the RTD can provide these measurements if a CR3000 or CR5000 datalogger is used.
The CNR4 has a solar shield that reduces the thermal effects on both the short-wave and long-wave measurements. A drying cartridge helps keep the radiometer’s electronics dry. The CNF4, an optional ventilation unit with heater, can be fitted onto the CNR4 to minimize the formation of dew as well as melt frost.
Benefits
- Research-grade performance
- Meniscus dome on upper long-wave detector allows water droplets to easily roll off of it and increases field of view to nearly 180°
- Internal temperature sensors provide temperature compensation of measurements
- Drying cartridge helps keep the electronics dry
- Compatible with the CNF4 ventilation unit with heater that reduces formation of dew and melts frost
- Separate outputs of short-wave and long-wave infrared radiation for better accuracy and more thorough quality assurance
- Solar shield reduces thermal effects on the sensors
Specifications
- Sensor
- Two thermopile pyranometers, two pyrgeometers, Pt100 RTD, and thermistor
- Measurement Description
- Measures incoming and outgoing short-wave and long-wave radiation
- Response Time
- < 18 s
- Temperature Dependence of Sensitivity
- < 4%
(-10° to +40°C)
- Sensitivity
- 5 to 20 μV W-1 m2
- Non-Linearity
- < 1%
- Tilt Error
- < 1%
- Directional Error
- < 20 W m-2 (pyranometer)
Angles up to 80° with 1000 W/m2 beam radiation - Operating Temperature Range
- -40° to +80°C
- Compliance
- Conforms to the CE guideline 89/336/EEC 73/23/EEC.
- Height
- 6.6 cm
(2.6 in.) dome-to-dome
- Width
- 11.1 cm
(4.4 in.)
- Length
- 23.5 cm
(9.3 in.)
40.4 cm(15.9 in.) with CNF4
- Weight
- 850 g
(30.0 oz) without cable
Pyranometer
- Spectral Range
- 305 to 2800 nm
- Uncertainty in Daily Total
- < 5%
(The uncertainty values are for a 95% confidence level.)
- Output Range
- 0 to 15 mV
(The output range is typical for atmospheric applications.)
Pyrgeometer
- Spectral Range
- 4500 to 42,000 nm
- Uncertainty in Daily Total
- < 10%
(The uncertainty values are for a 95% confidence level.)
- Output Range
- ±5 mV
(The output range is typical for atmospheric applications.)
Common Accessories
(5)CNR4CBL1
CNR4 Solar Cable
This cable connects the solar components of the CNR4 to a data logger. The CNR4CBL1 is constructed from a Santoprene®-jacketed cable that has eight individually-insulated, 26 AWG conductors.
OrderableCNR4CBL2
CNR4 Temperature Cable
This cable connects the temperature components of the CNR4 to a data logger. The CNR4CBL2 is constructed from a Santoprene®-jacketed cable that has eight individually-insulated, 26 AWG conductors.
Orderable26120
Net Radiation Sensor Mounting Kit
The 26120 mounting kit attaches the CNR4 to a vertical pipe or a horizontal crossarm (CM202, CM204, or CM206). It uses screws to level the sensor.
OrderableCNF4
Ventilation and Heater Unit for CNR4
The CNF4 heater/ventilation unit fits onto the CNR4. It provides efficient air-flow over the domes and windows to minimize the formation of dew and reduce the frequency of cleaning. The integrated heater melts the frost.
Orderable39144
DIN Rail Terminal Kit with 6 Terminals and 17 Wires
The 39144 provides the needed DIN rail terminals, separator, and wires to connect any product to a data logger or other peripheral that requires 17 wires for connection. This kit provides the following wires: black (2), light blue, brown (2), yellow (2), green (2), red (2), clear (2), gray (2), and white (2). The color-coding of these wires matches the wire coloring of the product for ease in connection, maintenance, and troubleshooting.
Orderable
Ships With
(4)- Mounting Rod from original mfg
26006
CNR4 Replacement Drying Cartridge
OrderableQty 2- WRR Traceable Calibration CertificatesQty 2
- Extra Calibration Sticker from original mfg (to be put on CNF4 if used)
Compatibility
Mounting
To avoid shading or reflections and to promote spatial averaging, the CNR4 should be mounted at least 1.5 m above the ground or crop canopy and away from all obstructions or reflective surfaces that might adversely affect the measurement.
The CNR4 can be attached to a vertical pipe or horizontal crossarm. To do this, first connect the radiometer to its mounting rod. The mounting rod then attaches to the pipe or crossarm via the 26120 Net Radiation Sensor Mounting Kit. The kit includes adjustment screws for leveling the CNR4. The 26120 can withstand winds up to 120 mph.
Data Logger Considerations
Four differential channels or four single-ended channels are used to measure the radiation components. A voltage excitation channel and an additional single-ended channel are required to measure the thermistor. If the RTD is used to provide the temperature compensation measurement, a current excitation channel (only available on the CR3000 and CR5000) and a differential channel are required.
Compatible Products
(1)
Related Resources
Case Studies
China: Flux Cooperation
Flux studies over mountain forests (heterogeneous landscapes)
Northeast China
March 8, 2019
View
Peru: High-Elevation Weather on Glaciers
Glacier monitoring
Andes Mountains, Peru
March 25, 2015
View
Alaska: Eddy Covariance
Measuring eddy-covariance fluxes in cold-climate forest
Bonanza Creek Experimental Forest (a National Science Foundation Long-Term Ecological Research site in the Alaska interior)
June 19, 2013
View
Documents
Downloads
- CR1000X CNR4 Program using Thermistorv1
October 17, 2019
Software ApplicationsCR1000X program that uses differential terminals to measure the four radiation outputs and one excitation terminal and one single-ended terminal to measure the thermistor. The program measures the sensors every 1 second, performs the online processing of the data, and stores processed data to a data table called cnr4_data once every 60 minutes. It also stores the raw time-series data from CNR4 to data table called cnr4_ts.
- CR3000 CNR4 Program using Pt-100v1
October 17, 2019
Software ApplicationsCR3000 program measures the Pt-100 sensor for the body temperature of the CNR4. This program requires four differential channels to measure the four radiation outputs, one current excitation channel, and one differential channel for Pt-100 measurement. It measures the sensors every 1 second, performs the online processing of the data, and stores the processed data to a data table called cnr4_data once every 60 minutes. It also stores the raw time-series data from CNR4 to data table called cnr4_ts.
- CR1000X CNR4 Program Controlling the CNF4 Heater/Ventilatorv1
October 17, 2019
Software ApplicationsCR1000X program measures the CNR4 and controls the CNF4 heater/ventilator based on environmental conditions, and monitors the CNF4 tachometer. The program uses an EE181 temperature and relative humidity sensor and a 03002 Wind Sentry to provide the measurements for determining when to turn the fan and heater on and off. An A21REL-12 relay switches power to the CNF4.