LI200X Pyranometer Revision: 6/10 LI CO P YR PY R A N OM ET E R 2 0 0 23 C o p y r i g h t © 1 9 9 4 - 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 .
Warranty and Assistance The LI200X PYRANOMETER 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 obligation under this warranty is limited to repairing or replacing (at Campbell Scientific, Inc.'s option) defective products.
LI200X 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 1.1 Specifications............................................................................................1 2. Installation....................................................................2 3. Wiring.................................................
LI200X Table of Contents Tables 3-1. Connections to Campbell Scientific Dataloggers ................................... 4 4-1. Multipliers Required for Average Flux and Total Flux Density in Sl and English Units .................................................................... 6 4-2. Wiring for Example Programs................................................................ 6 A.4-1. Multipliers Required for Average Flux and Total Flux Density for SI and English Units for a LI200S Pyranometer ......
LI200X Pyranometer 1. General Description The LI200X measures incoming solar radiation with a silicon photovoltaic detector mounted in cosine-corrected head. The detector outputs current; a shunt resistor in the sensor cable converts the signal from current to voltage, allowing the LI200X to be measured directly by Campbell Scientific dataloggers. The LI200X is calibrated against an Eppley Precision Spectral Pyranometer to accurately measure sun plus sky radiation.
LI200X Pyranometer NOTE The black outer jacket of the cable is Santoprene® rubber. This compound was chosen for its resistance to temperature extremes, moisture, and UV degradation. However, this jacket will support combustion in air. It is rated as slow burning when tested according to U.L. 94 H.B. and will pass FMVSS302. Local fire codes may preclude its use inside buildings. LI CO P YR PY R A N OM ET E R 2 0 0 23 FIGURE 1-1. LI200X Pyranometer 2.
LI200X Pyranometer NOTE Remove the red cap after installing the sensor. Save this cap for shipping or storing the sensor. LI200X Pyranometer LI2003S CM225 Stand CM200 Series Crossarm FIGURE 2-1. CM225 Pyranometer Mounting Stand and CM202 Crossarm FIGURE 2-2.
LI200X Pyranometer FIGURE 2-3. 025 Crossarm Stand and 019ALU Crossarm 3. Wiring A schematic diagram of the LI200X is shown in Figure 3-1. Connections to Campbell Scientific dataloggers are given in Table 3-1. When Short Cut software is used to create the datalogger program, the sensor should be wired to the channels shown in the wiring diagram created by Short Cut. TABLE 3-1.
LI200X Pyranometer H RED 40.2 to 90.2 Ω L AG OR GND GND BLACK WHITE CLEAR FIGURE 3-1. LI200X Schematic NOTE If a 21X is used to measure the LI200X and powers a 12 VDC sensor, the current drawn by the 12 VDC sensor may cause a difference in ground potential between the 21X ground terminals and the reference ground point in the datalogger. This ground potential results in an offset on single ended measurements. This offset can be as large as ± 60 mV. Thus, single ended measurements should be avoided.
LI200X Pyranometer TABLE 4-1. Multipliers Required for Average Flux and Total Flux Density in Sl and English Units UNITS MULTIPLIER PROCESS Wm 200 Average MJ m-2 t * 0.0002 Total t * 0.2 Total 0.2 * (1.434) Average t * 0.2 * (0.0239) Total -2 -2 kJ m cal cm-2 min-1 -2 cal cm t = datalogger execution interval in seconds 4.1 Example Programs The following programs measure the LI200X every 10 seconds, and convert the mV output to Wm-2 and MJm-2.
LI200X Pyranometer 'Define Data Tables DataTable(Table1,True,-1) DataInterval(0,60,Min,10) Average(1,SlrW,FP2,False) EndTable DataTable(Table2,True,-1) DataInterval(0,1440,Min,10) Totalize(1,SlrMJ,IEEE4,False) EndTable 'Main Program BeginProg Scan(10,Sec,1,0) 'measure the LI200X VoltDiff(SlrW,1,mV7_5,1,True,0,_60Hz,1,0) ‘use 20mV range for ‘CR5000 and CR3000 ‘set negative values to zero If SlrW<0 Then SlrW=0 ‘convert mV to MJ/m2 for 10 second execution interval SlrMJ=SlrW*0.
LI200X Pyranometer ; set negative values to zero 2: If (X<=>F) (P89) 1: 3 X Loc [ SlrW 2: 4 < 3: 0 F 4: 30 Then Do ] 3: Z=F x 10^n (P30) 1: 0 F 2: 0 n, Exponent of 10 3: 3 Z Loc [ SlrW ] 4: End (P95) ; convert mV to MJ/m2 for 10 second execution interval 5: Z=X*F (P37) 1: 3 2: 0.002 3: 4 X Loc [ SlrW ] F Loc [ SlrMJ ] ; convert mV to W/m2 6: Z=X*F (P37) 1: 3 2: 200.
LI200X Pyranometer 13: Real Time (P77) 1: 1220 Year,Day,Hour/Minute (midnight = 2400) 14: Resolution (P78) 1: 1 High Resolution 15: Totalize (P72) 1: 1 Reps 2: 4 Loc [ SlrMJ ] 16: Resolution (P78) 1: 0 Low Resolution 4.2 Total Solar Radiation If the solar radiation is totalized in units of kJ m-2, there is a possibility of overranging the output limits. For CRBasic dataloggers, you can avoid this by using the IEEE4 or long data format.
LI200X Pyranometer CAUTION Handle the sensor carefully when cleaning. Be careful not to scratch the surface of the sensor. Recalibrate the LI200X every two years. Obtain an RMA number before returning the LI200X to Campbell Scientific, Inc. for recalibration. 6. Calibration LI200X pyranometers output a current that is proportional to the incoming solar radiation. Each LI200X has a unique calibration factor.
Appendix A. LI200S Pyranometer A.1 LI200S Pyranometer LI200S pyranometers have a 100 ohm shunt resistor built into the cable. They can be directly measured by Campbell Scientific dataloggers. The input range and multipliers vary from one pyranometer to another. See Sections A.3 and A.4 for calculating the proper input range and multiplier. A.1.1 Wiring The red lead is connected to the high side (H) of a differential input channel and the black lead to the corresponding low side (L).
Appendix A. LI200S Pyranometer A.3 Input Range The following is an example of how to determine the optimum input range for a given sensor calibration and maximum expected irradiance. This is an example only. Your values will be different. This example uses the calibration provided by LI-COR, Inc. Assume that the sensor calibration is 87 µA kW-1 m2. The pyranometer outputs current which is converted to voltage by the 100 Ω shunt resistor in the cable or on the wiring panel.
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