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Campbell CNR4 Instruction Manual

Other manuals for CNR4: User Manual, Instruction Manual
Manual is about: Net Radiometer

Summary of CNR4

  • Page 1

    Cnr4 net radiometer revision: 9/13 c o p y r i g h t © 2 0 0 0 - 2 0 1 3 c a m p b e l l s c i e n t i f i c , i n c ..

  • Page 3

    Warranty and assistance this equipment is warranted by campbell scientific (canada) corp. ("csc") to be free from defects in materials and workmanship under normal use and service for twenty-four (24) months from date of shipment unless specified otherwise. ***** batteries are not warranted. ***** c...

  • Page 4: Please Read First

    Please read first about this manual please note that this manual was originally produced by campbell scientific inc. (csi) primarily for the us market. Some spellings, weights and measures may reflect this origin. Some useful conversion factors: area: 1 in 2 (square inch) = 645 mm 2 length: 1 in. (i...

  • Page 5: Table of Contents

    Table of contents pdf viewers: these page numbers refer to the printed version of this document. Use the pdf reader bookmarks tab for links to specific sections. 1. Introduction .................................................................1 2. Cautionary statements..................................

  • Page 6

    Table of contents 8. Troubleshooting........................................................30 8.1 testing the pyranometer.................................................................... 30 8.2 testing the pyrgeometer.................................................................... 31 8.3 tes...

  • Page 7

    Table of contents b-2. Attaching the cnf4 to cnr4 using pan-head screws and washers .........................................................................................B-4 b-3. Making sure the cables are clear from the edges..............................B-5 b-4. Cnf4 solar shield and four flat-...

  • Page 8

    Table of contents iv.

  • Page 9: Cnr4 Net Radiometer

    Cnr4 net radiometer 1. Introduction the cnr4 is a research-grade net radiometer that measures the energy balance between incoming and outgoing radiation. Our dataloggers measure the cnr4’s output. This net radiometer offers a professional solution for scientific-grade energy balance studies. Before ...

  • Page 10: 4. Quickstart

    Cnr4 net radiometer 4. Quickstart please review section 7, operation , for wiring and crbasic programming. Appendix b, cnf4 heater/ventilator , provides information about using the cnf4 heater/ventilator. 4.1 siting considerations 1. Mount the sensor so no shadow will be cast on it at any time of da...

  • Page 11

    Cnr4 net radiometer 2. Attach the 26120 mounting bracket to the vertical mounting pipe, or cm200-series crossarm using the provided u-bolt (see figure 4-2). Figure 4-2. Attaching the cnr4 onto the mounting rod (pn 26120) using vertical pole or horizontal crossarm 3. Insert the sensor’s support arm i...

  • Page 12

    Cnr4 net radiometer 6. Perform the fine leveling using the two spring-loaded leveling screws— one on the front and the other on the back of the bracket. 7. Route the sensor cable to the instrument enclosure. 8. Use the uv-resistant cable ties included with the tripod or tower to secure the cable to ...

  • Page 13

    Cnr4 net radiometer 2. Select the datalogger and enter the scan interval. 3. Select cnr4 net radiometer, and select the right arrow (in center of screen) to add it to the list of sensors to be measured, and then select next . 5.

  • Page 14

    Cnr4 net radiometer 4. Enter the sensitivity values supplied on the manufacturer’s certificate of calibration; these sensitivity values are unique to each sensor. The public variables defaults can typically be used. After entering the information, click on ok, and then select next . 5. Choose the ou...

  • Page 15: 5. Overview

    Cnr4 net radiometer 7. In the confirm window, click yes to download the program to the datalogger. 8. Click on wiring diagram and wire according to the wiring diagram generated by short cut. 5. Overview the cnr4 net radiometer consists of a pyranometer pair, one facing upward, the other facing downw...

  • Page 16: 6. Specifications

    Cnr4 net radiometer and is resistant to a variety of pollutants and uv-radiation. The mounting rod can be unscrewed for transport. An optional ventilation unit with a heater, cnf4, is designed as an extension of the solar shield and can be fitted to the cnr4 or retrofitted later. The heater/ventilat...

  • Page 17

    Cnr4 net radiometer the properties of the cnr4 are mainly determined by the properties of the individual probes. Generally the accuracy of the cnr4 will be higher than that of competitive net-radiometers, because the solar radiation measurement performed by the pyranometer is accurate, and offers a ...

  • Page 18

    Cnr4 net radiometer 6.1 cnr4 specifications sensor sensitivities: four probes with 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 bu...

  • Page 19

    Cnr4 net radiometer directional error*: 2 at angle up to 80° with 1000 w/m 2 zero offset due to 0 to -200 w/m 2 ir net irradiance*: 2 zero offset due to temperature change*: 2 (5 k/hr temperature change) 2 (with cnf4 installed) operating temperature: –40°c to +80°c field of view upper detector: lowe...

  • Page 20

    Cnr4 net radiometer field of view upper: lower: 180 degrees 150 degrees net-irradiance: –250 to +250 w/m 2 non-stability: window heating offset: 2 (1000 w/m 2 solar irradiance) uncertainty in daily total: calibration typical signal output for atmospheric application: ±5 mv temperature sensors thermi...

  • Page 21: 7. Operation

    Cnr4 net radiometer 7. Operation 7.1 using the cnr4 in the four separate components mode in the four separate components mode configuration (measuring two short- wave radiation signals and two long-wave signals), all signals are measured separately. Calculation of net-radiation and albedo can be don...

  • Page 22

    Cnr4 net radiometer for the pyrgeometer only e = v/c + 5.67 x 10 -8 x t 4 (7-2) in this equation, c is the sensitivity of the sensor. T is in kelvin, and not in celsius or fahrenheit. Note the downward-facing pyrgeometer measures the far infrared radiation that is emitted by the ground. The upward-f...

  • Page 23

    Cnr4 net radiometer table 7-1. Resistance values versus cnr4’s thermistor temperature in °c. Temperature [ r c] resistance [ : ] temperature [ r c] resistance [ : ] temperature [ r c] resistance [ : ] –13 –12 –11 –10 –9 –8 –7 –6 –5 –4 –3 –2 –1 55170 52480 49940 47540 45270 43110 41070 39140 37310 35...

  • Page 24

    Cnr4 net radiometer table 7–2. Resistance values versus cnr4’s pt–100 temperature in °c. Temperature [°c] resistance [ : ] temperature [°c] resistance [ : ] temperature [°c] resistance [ : ] –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 –...

  • Page 25

    Cnr4 net radiometer 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 for quality control of your measured data at a specific site. 7.1.5 ca...

  • Page 26

    Cnr4 net radiometer 7.1.7 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)} (7-8) w...

  • Page 27

    Cnr4 net radiometer figure 7-2. 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 appendix c, cr3000 program for measuring pt-100 temperature sensor . The four radiati...

  • Page 28

    Cnr4 net radiometer figure 7-4. Labels on the pigtail end of the temp cable. Table 7-3. Datalogger connections for differential measurement function wire color cr1000 cr3000/cr5000 pyranometer up signal red differential input (h) differential input (h) pyranometer up r rential input (l) eference *bl...

  • Page 29

    Cnr4 net radiometer 7.3 datalogger pro ming single-ended measurement. If differential channels are not available, single- ptability of a single-ended ed by simply comparing the results of single- y, 7.3.1 sensor sens rate nufacturer. They show the sensor serial number and sensitivity values for four...

  • Page 30

    Cnr4 net radiometer average short-wave net radiation average long-wave net radiation average albedo average net radiation 'cr1000 series dat logger a ' 'cnr4 program 'this program meas er ures cnr4 four-component net radiomet 'this program also nr4 measures the thermistor inside the c ' 'user must e...

  • Page 31

    Cnr4 net radiometer units logger_temp = d gc e units batt_volt s = volt 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 long_up_corr = w/m^2 units long_dn_corr = w/m^2 units rs_net = w/m^2 units rl_net = w/m^2 ...

  • Page 32

    Cnr4 net radiometer scan (1,sec,3,0) paneltemp (logger_temp,250) battery (batt_volt) 'cnr4 radiation measurements voltdiff (cnr4(),4,mv20c,1,true ,0,_60hz,cnr4_mult(),0) 'cnr4 thermistor measurement brhalf (vs_vx,1,mv2500,16,vx2,1,2500,true ,0,250,1.0,0) rs = 1000*(vs_vx/(1-vs_vx)) cnr4_t_c = 1/(1.0...

  • Page 33

    Cnr4 net radiometer 'cr3000 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...

  • Page 34

    Cnr4 net radiometer units long_up_corr = w/m^2 units long_dn_corr = w/m^2 units rs_net = w/m^2 units rl_net = w/m^2 units albedo = w/m^2 units rn = w/m^2 dim rs, vs_vx 'cnr4 sensitivities: refer to the certificate of calibration from kipp & zonen for sensitivity values 'for each probes, and enter th...

  • Page 35

    Cnr4 net radiometer '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-wave radiation val...

  • Page 36

    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...

  • Page 37

    Cnr4 net radiometer units cnr4_t_k = k units long_up_corr = w/m^2 units long_dn_corr = w/m^2 units rs_net = w/m^2 units rl_net = w/m^2 units albedo = w/m^2 units rn = w/m^2 dim rs, vs_vx 'cnr4 sensitivities: refer to the certificate of calibration from kipp & zonen for sensitivity values 'for each p...

  • Page 38: 8. Tr

    Cnr4 net radiometer 'convert cnr4 temperature to kelvin cnr4_t_k = cnr4_t_c+273.15 'correct the long-wave radiation values from pyrgeometers long_up_corr = long_up+5.67e-8*cnr4_t_k^4 long_dn_corr = long_dn+5.67e-8*cnr4_t_k^4 'compute short-wave net radiation rs_net = short_up - short_dn 'compute lon...

  • Page 39

    Cnr4 net radiometer voltmeter to its most sensitive range setting. Darken the sensor. The signal n take up to one minute. Small deviations al effects, such as touching ct can be demonstrated by the zero offset is within specifications, proceed with the third test. Uld be exposed to light. The signal...

  • Page 40: 9. Maintenance

    Cnr4 net radiometer 9. Maintenance n. 9.1 cleaning w 9.2 recalibrat e uthorized kipp & zonen calibration facility. Librated every two years. Alternatively, one can of pyrgeometers, 9.3 replacing screws compartment sealed. The cnr4 comes with two spare drying cartridges. Additional drying an be purch...

  • Page 41

    Cnr4 net radiometer 33 figure 9-1. Replacing the drying cartridge nt parts the following is the list of replacement 9.4 replaceme parts for the cnr4 and cnf4 (heater/ventilator) available from campbell scientific. Csi part number description cnr4cbl1-l replacement cnr4 solar cable cnr4cbl2-l replace...

  • Page 42

    Cnr4 net radiometer 34.

  • Page 43: Measurements Under Different

    Appendix a. Cnr4 performance and measurements under different conditions 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 or clear...

  • Page 45

    Appendix a. Cnr4 performance and measurements under different conditions upwelling signal (downward facing) pyrgeometer 20 30 Ͳ 30 Ͳ 20 Ͳ 10 0 10 0: 00: 00 1: 00: 00 2: 00: 00 3: 00: 00 4: 00: 00 5: 00: 00 6: 00: 00 :0 0 00 00 7: 00: 00 8: 00: 00 9: 00: 00 10 :00: 00 11 :00: 00 12 :00: 00 13 :00: 00...

  • Page 46

    Appendix a. Cnr4 performance and measurements under different conditions 4 / 1 8 10 67 . 5 cg3 upper e e temperatur sky »¼ º «¬ ª a-4 (a-1) 4 / 1 8 10 67 . 5 »¼ º «¬ ª cg3 lower e e temperatur ground (a-2).

  • Page 47: 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 gained by heating will be larger than the errors introduced by heating. In both the pyranometer and the pyrgeometer, thermal ...

  • Page 48

    Appendix b. Cnf4 heater/ventilator appendix b. Cnf4 heater/ventilator 10 watt power available? Not available do not heat available consider options below tions below clock and relay available? Not available do not b-2 10 watt power available? Not available do not heat available consider op clock and...

  • Page 49: Unit to Cnr4

    Appendix b. Cnf4 heater/ventilator b.2 attaching the optional cnf4 heater/ventilato unit to cnr4 r with 1. The cnf4 heater/ventilator unit comes with the following: the heater/ventilator, the white solar shield, three pan-head screws washers, and four flat-head screws as shown in figure b-1. Figure ...

  • Page 50

    Appendix b. Cnf4 heater/ventilator 2. Attach the heater/ventilator unit unto the bottom of the cnr4 sensor, using the t ws and washers, as shown in figure b-2. Make sure that the pyranometer and the pyrgeometer windows are not scratched during the installation. Hree pan-head scre figure b-2. Attachi...

  • Page 51

    Appendix b. Cnf4 heater/ventilator 3. Make sure the cables are cleared from the edges of the cnf4, as show figure b-3, and place the white solar shield over it. Use the four fl h as show n in at- ead screws provided to complete the solar shield installation to the cnf4, n in figure b-4 and figure b-...

  • Page 52

    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 sens...

  • Page 53: B.3 Wiring

    Appendix b. Cnf4 heater/ventilator b.3 wiring aking the differential measurement. Table b-1. Cr1000 and cr3000 datalogger connections for differential measurement with heater/ventilator control the following table shows the recommended datalogger wiring for using the cnr4 sensor with the cnf4 heater...

  • Page 54: Heater/ventilator Control

    Appendix b. Cnf4 heater/ventilator b.4 example b, cr3000 datalogger program with heater/ventilator control 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 this example pro...

  • Page 55

    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 vent d) ilator + (re ' 'sw12v-2 cnf4 heater een) +...

  • Page 56

    Appendix b. Cnf4 heater/ventilator '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 pyrge...

  • Page 57

    Appendix b. Cnf4 heater/ventilator 'compute net radiation rn = rs_net + rl_net 'cnf4 ventilator control - the ventilator will be turned on when flag(1) is set high sw12 (1,flag(1)) 'cnf4 heater control - the heater will be turned on when flag(2) is set high sw12 (2,flag(2)) calltable cnr4_data callt...

  • Page 58

    Appendix b. Cnf4 heater/ventilator b-12.

  • Page 59: Appe

    Appe gram for measuring pt-100 temperature sensor ndix c. Cr3000 pro example c measures the pt-100 senso te perature of the c r4. Gram requ s four different measure the four radi ion ts, one current excitation channel, and one differential channel for pt-100 measurement. The program measures the sen...

  • Page 60

    Appendix c. Cr3000 program for measuring pt-100 temperature sensor 'cr3000 series dat logger a ' 'cnr4 program 'this program meas res cnr4 four-component net radiometer u 'this program also measures the pt-100 sensor inside the cnr4 ' 'user must enter the sensitivity values for all four probes in th...

  • Page 61

    Appendix c. Cr3000 program for measuring pt-100 temperature sensor units cnr4_t_k = k units long_up_corr = w/m^2 units long_dn_corr = w/m^2 units rs_net = w/m^2 units rl_net = w/m^2 units albedo = w/m^2 units rn = w/m^2 dim cnr4_prt_r, rs_r0 'cnr4 sensitivities: refer to the certificate of calibrati...

  • Page 62

    Appendix c. Cr3000 program for measuring pt-100 temperature sensor c-4 easurement 'prt (pt-100) temperature m resistance (cnr4_prt_r,1,mv200,8,ix1,1,1500,true,true,0,_60hz,1,0) rs_r0 = cnr4_prt_r/100 prt (cnr4_t_c,1,rs_r0,1,0) 'convert cnr4 temperature to kelvin cnr4_t_k = cnr4_t_c+273.15 'correct t...

  • Page 64

    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...