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Campbell CNR4 Instruction Manual
Summary of CNR4
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Cnr4 net radiometer revision: 11/10 c o p y r i g h t © 2 0 0 0 - 2 0 1 0 c a m p b e l l s c i e n t i f i c , i n c ..
Page 2: Warranty and Assistance
Warranty and assistance the cnr4 net radiometer is warranted by campbell scientific, inc. To be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless specified otherwise. Batteries have no warranty. Campbell scientific, inc.'s...
Page 3: Cnr4 Table of Contents
Cnr4 table of contents pdf viewers note: these page numbers refer to the printed version of this document. Use the adobe acrobat® bookmarks tab for links to specific sections. 1. General description.....................................................1 2. Sensor specifications .........................
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Cnr4 table of contents 9. Maintenance and recalibration ................................29 9.1 cleaning windows and domes.............................................................. 29 9.2 recalibration .......................................................................................... 30 9...
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Cnr4 table of contents tables 5-1. Resistance values versus cnr4's thermistor temperature in °c ...........11 5-2. Resistance values versus cnr4's pt-100 temperature in °c .................12 6-1. Datalogger connections for differential measurement ........................16 6-2. Datalogger connecti...
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Cnr4 table of contents iv.
Page 7: Cnr4 Net Radiometer
Cnr4 net radiometer 1. General description the cnr4 is a four component net radiometer that measures the energy balance between incoming and outgoing radiation. The cnr4 net radiometer consists of a pyranometer pair, one facing upward, the other facing downward, and a pyrgeometer pair in a similar c...
Page 8: 2. Sensor Specifications
Cnr4 net radiometer 2. Sensor specifications the cnr4 consists of two pyranometers, for measuring short-wave radiation, and of two pyrgeometers for measuring long-wave radiation. Two temperature sensors are available as standard, a thermistor and a pt-100. The optional heater/ventilator unit cnf4-l ...
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Cnr4 net radiometer 2.1 cnr4 specifications sensor sensitivities: four probes have unique sensitivity values. Please refer to the calibration sheets or label on the bottom of the sensor for the sensitivity values. Operating temperature: -40 to +80°c (-40 to 176°f) operating humidity: 0 to 100 % rh b...
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Cnr4 net radiometer 2.2 pyranometer specifications * indicates iso specifications. Spectral range: 305 to 2800 nm (50% points) sensitivity: 10 to 20 µv/w/m 2 response time*: non-linearity*: -2 irradiance) non-stability*: temperature dependence of sensitivity*: tilt response*: 2 directional error*: 2...
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Cnr4 net radiometer 2.3 pyrgeometer specifications spectral range: 4.5 μm to 42 μm (50% points) sensitivity: 5 to 15 μv/w/m 2 impedance: 20 Ω to 200 Ω (typically 50) response time: non-linearity: 2 irradiance) temperature dependence of sensitivity: tilt error: angle off horizontal) zero offset due t...
Page 12: 3. Installation
Cnr4 net radiometer 2.4.1 cnf4 specifications heater power consumption: 10 w @ 12 vdc (15 Ω) ventilator power consumption: supply voltage: 5 w @ 12 vdc 8 to 13.5 vdc weight: 1.11 lbs (0.5 kg) operating temperature: -40 to +80°c 3. Installation for measurement of net radiation, it is most important t...
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Cnr4 net radiometer do not attempt to rotate the instrument using the sensor heads, or you may damage the sensors; use the mounting rod only. Note 4. Perform the fine levelling using the two spring-loaded levelling screws: one on the front and the other on the back of the bracket. Figure 3-1. Attach...
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Cnr4 net radiometer figure 3-2. Attaching the cnr4 onto the mounting rod (csi p/n 26120) using vertical pole or horizontal crossarm. For installation in buildings or in solar energy applications, one will often have to mount the cnr4 parallel to the surface that is being studied. This may be in a ti...
Page 15: Mode
Cnr4 net radiometer 5. Using the cnr4 in the four separate components mode in the four separate components mode configuration (measuring two short- wave radiation signals, two long-wave signals), all signals are measured separately. Calculation of net-radiation and albedo can be done on-line by the ...
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Cnr4 net radiometer colder. This means that for estimating the far infrared radiation that is generated by the object that is faced by the pyrgeometer, usually the sky or the soil, you will have to take the pyrgeometer temperature, t, into account. This is why the temperature sensors are incorporate...
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Cnr4 net radiometer the thermistor measurement can be done by the datalogger, using the half bridge measurement method which requires one voltage excitation and one single-ended analog channel. Alternatively, you can use the pt-100 to make the temperature measurement. In order to make the temperatur...
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Cnr4 net radiometer table 5-2. Resistance values versus cnr4's pt-100 temperature in °c. Temperature [°c] resistance [ Ω] temperature [°c] resistance [ Ω] temperature [°c] resistance [ Ω] -30 -29 -28 -27 -26 -25 -24 -23 -22 -21 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 8...
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Cnr4 net radiometer in the equation above, e is calculated according to the equation 5-1. Albedo will always be smaller than 1. Checking this can be used as a tool for quality assurance of your data. If you know the approximate albedo at your site, the calculation of albedo can also serve as a tool ...
Page 20: 6. Wiring
Cnr4 net radiometer 5.7 calculation of net (total) radiation in the four separate components mode, net radiation, r n , can be calculated using the individual sensor measurement results: r n = {(e upper pyranometer) - (e lower pyranometer)} + {(e upper pyrgeometer) - (e lower pyrgeometer)} (5-8) whe...
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Cnr4 net radiometer figure 6-2. The marks on the end of the cnr4: s for solar cable, and t for temp cable. The measurement details for pt-100 sensor, including the wiring diagram and sample program are explained in the appendix c of this manual. The four radiation outputs can be measured using diffe...
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Cnr4 net radiometer figure 6-4. Labels on the pigtail end of the temp cable. Table 6-1. Datalogger connections for differential measurement function wire color cr1000 cr3000/cr5000 pyranometer up signal red differential input (h) differential input (h) pyranometer up reference *blue differential inp...
Page 23: 7. Datalogger Programming
Cnr4 net radiometer 7. Datalogger programming the cnr4 outputs four voltages that typically range from 0 to 15 mv for the pyranometers, and ± 5 mv for the pyrgeometers. A differential voltage measurement is recommended because it has better noise rejection than a single-ended measurement. If differe...
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Cnr4 net radiometer average corrected long-wave radiation (pyrgeometer up) average corrected long-wave radiation (pyrgeometer down) average short-wave net radiation average long-wave net radiation average albedo average net radiation 'cr1000 series datalogger ' 'cnr4 program 'this program measures c...
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Cnr4 net radiometer public cnr4_t_c 'cnr4 thermistor temperature in celcius public cnr4_t_k 'cnr4 thermistor temperature in kelvin public long_up_corr 'downwelling long-wave radiation with temperature correction public long_dn_corr 'upwelling long-wave radiation with temperature correction public rs...
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Cnr4 net radiometer average (1,rl_net,ieee4,false) average (1,albedo,ieee4,false) average (1,rn,ieee4,false) endtable datatable (cnr4_ts,true,-1) datainterval (0,1,sec,10) cardout (1,-1) sample (4,cnr4(1),ieee4) sample (1,cnr4_t_k,ieee4) endtable beginprog 'load the multiplier values for the cnr4 cn...
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Cnr4 net radiometer 7.2.2 example 2, cr3000 program using differential measurements the program example 2 requires four differential channels to measure the four radiation outputs and one excitation channel and one single-ended channel to measure the thermistor. The program measures the sensors ever...
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Cnr4 net radiometer '8h '8l cnr4 thermistor signal (white) 'gnd cnr4 thermistor signal reference (black) ' cnr4 thermistor shield (clear) ' 'voltage excitation ' 'vx1 cnr4 thermistor voltage excitation (red) ' 'cnr4 sensor public logger_temp, batt_volt public cnr4(4) alias cnr4(1) = short_up alias c...
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Cnr4 net radiometer 'cnr4 multipliers public cnr4_mult(4) const pyranometer_up_mult = 1000/pyranometer_up_sensitivity '(w/m^2/mv) const pyranometer_dn_mult = 1000/pyranometer_dn_sensitivity '(w/m^2/mv) const pyrgeometer_up_mult = 1000/pyrgeometer_up_sensitivity '(w/m^2/mv) const pyrgeometer_dn_mult ...
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Cnr4 net radiometer 'compute short-wave net radiation rs_net = short_up - short_dn 'compute long-wave net radiation rl_net = long_up - long_dn 'compute albedo albedo = short_dn/short_up 'compute net radiation rn = rs_net + rl_net calltable cnr4_data calltable cnr4_ts nextscan endprog 7.2.3 example 3...
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Cnr4 net radiometer 'cr5000 series datalogger ' 'cnr4 program 'this program measures cnr4 four-component net radiometer 'this program also measures the thermistor inside the cnr4 ' 'user must enter the sensitivity values for all four probes in the program and save/compile 'prior to downloading it to...
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Cnr4 net radiometer public rl_net 'long-wave net radiation public albedo 'albedo public rn 'total net radiation units logger_temp = degc units batt_volt = volts units short_up = w/m^2 units short_dn = w/m^2 units long_up = w/m^2 units long_dn = w/m^2 units cnr4_t_c = deg_c units cnr4_t_k = k units l...
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Cnr4 net radiometer datatable (cnr4_ts,true,-1) datainterval (0,1,sec,10) cardout (1,-1) sample (4,cnr4(1),ieee4) sample (1,cnr4_t_k,ieee4) endtable beginprog 'load the multiplier values for the cnr4 cnr4_mult(1) = pyra_up_mult cnr4_mult(2) = pyra_dn_mult cnr4_mult(3) = pyrg_up_mult cnr4_mult(4) = p...
Page 34: 8. Troubleshooting
Cnr4 net radiometer 8. Troubleshooting if there is no indication as to what may be the problem, start performing the following "upside-down test", which is a rough test for a first diagnosis. It can be performed both outdoors and indoors. Indoors, a lamp can be used as a source for both short-wave a...
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Cnr4 net radiometer 8.2 testing the pyrgeometer it is assumed that the zero offset is no more than a few watts per square meter (see second test in section 8.1). The cnr4 body and the ambient air should be at the same temperature as much as possible. Let the pyrgeometer rest for at least five minute...
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Cnr4 net radiometer 9.2 recalibration for quality assurance of the measured data, the manufacturer recommends the cnr4 be recalibrated on a regular schedule by an authorized kipp & zonen calibration facility. The cnr4 should be recalibrated every two years. Alternatively, one can check the sensor ca...
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Cnr4 net radiometer 9.4 replacement parts the following is the list of replacement parts for the cnr4 and cnf4 (heater/ventilator) available from campbell scientific. Csi part number description cnr4cbl1-l replacement cnr4 solar cable cnr4cbl2-l replacement cnr4 temperature cable cnf4cbl-l replaceme...
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Cnr4 net radiometer 32.
Page 39: Measurements Under Different
Appendix a. Cnr4 performance and measurements under different conditions below, table a-1 shows what one might typically expect to measure under different meteorological conditions. The first parameter is day and night. At night, the solar radiation is zero. The second column shows if it is cloudy o...
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Appendix a. Cnr4 performance and measurements under different conditions figure a-1. Different measurement conditions and signals. Upper pyrgeometer day with alternating cloud fields ‐180 ‐170 ‐160 ‐150 ‐140 ‐130 ‐120 ‐110 ‐100 ‐90 ‐80 ‐70 ‐60 ‐50 ‐40 ‐30 ‐20 ‐10 0 10 20 30 0:00: 00 1:00: 00 2:00: 0...
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Appendix a. Cnr4 performance and measurements under different conditions upwelling signal (downward facing) pyrgeometer ‐30 ‐20 ‐10 0 10 20 30 0: 00: 00 1: 00: 00 2: 00: 00 3: 00: 00 4: 00: 00 5: 00: 00 6: 00: 00 7: 00: 00 8: 00: 00 9: 00: 00 10 :00: 00 11 :00: 00 12 :00: 00 13 :00: 00 14 :00: 00 15...
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Appendix a. Cnr4 performance and measurements under different conditions 4 / 1 8 10 67 . 5 ⎥⎦ ⎤ ⎢⎣ ⎡ ⋅ = − cg3 upper e ature sky temper (b-1) 4 / 1 8 10 67 . 5 ⎥⎦ ⎤ ⎢⎣ ⎡ ⋅ = − cg3 lower e e temperatur ground (b-2) a-4.
Page 43: B.1 General Information
Appendix b. Cnf4 heater/ventilator whenever the heater is used, the heating may cause errors in the measurement of the sensor temperature. Under most conditions the accuracy that is gained by heating will be larger than the errors that are introduced by heating. Note in both the pyranometer and the ...
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Appendix b. Cnf4 heater/ventilator 10 watt power available? Not available do not heat available consider options below clock and relay available? Not available do not heat (csi recommendation) available heat from 1 hour before the sunset until 1 hour after the sunrise. The heater power can be contro...
Page 45: Unit to Cnr4
Appendix b. Cnf4 heater/ventilator b.2 attaching the optional cnf4 heater/ventilator unit to cnr4 1. The cnf4 heater/ventilator unit comes with the following: the heater/ventilator, the white solar shield, three pan-head screws with washers, and four flat-head screws as shown in figure b-1. Figure b...
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Appendix b. Cnf4 heater/ventilator 2. Attach the heater/ventilator unit unto the bottom of the cnr4 sensor, using the three pan-head screws and washers, as shown in figure b-2. Make sure that the pyranometer and the pyrgeometer windows are not scratched during the installation. Figure b-2. Attaching...
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Appendix b. Cnf4 heater/ventilator 3. Make sure the cables are cleared from the edges of the cnf4, as shown in figure b-3, and place the white solar shield over it. Use the four flat-head screws provided to complete the solar shield installation to the cnf4, as shown in figure b-4 and b-5. Figure b-...
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Appendix b. Cnf4 heater/ventilator figure b-5. Attaching the solar shield to cnf4 using four flat-head screws. 4. Once the cnf4 heater/ventilator unit is attached to the bottom side of the cnr4, the cnf4 will cover the label that contains the serial number and the sensitivity values for the four sen...
Page 49: B.3 Wiring
Appendix b. Cnf4 heater/ventilator b.3 wiring the following table shows the recommended datalogger wiring for using the cnr4 sensor with the cnf4 heater/ventilator while making the differential measurement. Table b-1. Cr1000 and cr3000 datalogger connections for differential measurement with heater/...
Page 50: Heater/ventilator Control
Appendix b. Cnf4 heater/ventilator b.4 example b, cr3000 datalogger program with heater/ventilator control the program example b measures the four radiation outputs, thermistor temperature, and controls the ventilator and heater, using sw12v-1 and sw12v-2 channels on the cr3000, respectively. In thi...
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Appendix b. Cnf4 heater/ventilator ' ' '8h '8l cnr4 thermistor signal (white) 'gnd cnr4 thermistor signal reference (black) ' cnr4 thermistor shield (clear) ' 'voltage excitation ' 'vx1 cnr4 thermistor voltage excitation (red) ' 'power out 'sw12v-1 cnf4 ventilator + (red) ' 'sw12v-2 cnf4 heater + (g...
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Appendix b. Cnf4 heater/ventilator dim rs, vs_vx 'cnr4 sensitivities: refer to the certificate of calibration from kipp & zonen for sensitivity values 'for each probes, and enter them below. Const pyranometer_up_sensitivity = 15.35 'unique sensitivity for upper pyranometer '(microv/w/m^2) const pyra...
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Appendix b. Cnf4 heater/ventilator 'cnr4 thermistor measurement brhalf (vs_vx,1,mv5000,16,vx1,1,2500,true ,0,250,1.0,0) rs = 1000*(vs_vx/(1-vs_vx)) cnr4_t_c = 1/(1.0295e-3+2.391e-4*ln(rs)+1.568e-7*(ln(rs))^3)-273.15 'convert cnr4 temperature to kelvin cnr4_t_k = cnr4_t_c+273.15 'correct the long-wav...
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Appendix b. Cnf4 heater/ventilator b-12 pulling it straight out. Inspect the fan inside for any object that might impede the fan’s rotation. Upon completing the inspection, put the filter and the cover back in place. B.5.3 replacing the filter for the ventilator the filter needs to be checked for ev...
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Appendix c. Cr3000 program for measuring pt-100 temperature sensor the program example c measures the pt-100 sensor for the body temperature of the cnr4. This program requires four differential channels to measure the four radiation outputs, and one current excitation channel and one differential ch...
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Appendix c. Cr3000 program for measuring pt-100 temperature sensor 'cr3000 series datalogger ' 'cnr4 program 'this program measures cnr4 four-component net radiometer 'this program also measures the pt-100 sensor inside the cnr4 ' 'user must enter the sensitivity values for all four probes in the pr...
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Appendix c. Cr3000 program for measuring pt-100 temperature sensor public cnr4_t_c 'cnr4 thermistor temperature in celcius public cnr4_t_k 'cnr4 thermistor temperature in kelvin public long_up_corr 'downwelling long-wave radiation with temperature correction public long_dn_corr 'upwelling long-wave ...
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Appendix c. Cr3000 program for measuring pt-100 temperature sensor c-4 average (1,albedo,ieee4,false) average (1,rn,ieee4,false) endtable datatable (cnr4_ts,true,-1) datainterval (0,1,sec,10) cardout (1,-1) sample (4,cnr4(1),ieee4) sample (1,cnr4_t_k,ieee4) endtable beginprog 'load the multiplier va...
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Campbell scientific companies campbell scientific, inc. (csi) 815 west 1800 north logan, utah 84321 united states www.Campbellsci.Com • info@campbellsci.Com campbell scientific africa pty. Ltd. (csaf) po box 2450 somerset west 7129 south africa www.Csafrica.Co.Za • cleroux@csafrica.Co.Za campbell sc...