How it Works
Campbell Scientific
Loading...
SI-111
User Manual
18 pgs626.51 Kb0
Table of contents
Loading...

Campbell Scientific SI-111 User Manual

Download
SI-111 Precision
Infrared Radiometer
Revision: 7/13
Copyright © 2002-2013
Campbell Scientific, Inc.,
Apogee Instruments, Inc.

Warranty

Assistance

Products may not be returned without prior authorization. The following contact information is for US and international customers residing in countries served by Campbell Scientific, Inc. directly. Affiliate companies handle repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company serves
your country.
To obtain a Returned Materials Authorization (RMA), contact CAMPBELL SCIENTIFIC, INC., phone (435) 227-9000. After an applications engineer determines the nature of the problem, an RMA number will be issued. Please write this number clearly on the outside of the shipping container. Campbell Scientific’s shipping address is:
CAMPBELL SCIENTIFIC, INC. RMA#_____ 815 West 1800 North Logan, Utah 84321-1784
For all returns, the customer must fill out a “Statement of Product Cleanliness and Decontamination” form and comply with the requirements specified in it. The form is available from our web site at www.campbellsci.com/repair. A completed form must be either emailed to repair@campbellsci.com or faxed to (435) 227-9106. Campbell Scientific is unable to process any returns until we receive this form. If the form is not received within three days of product receipt or is incomplete, the product will be returned to the customer at the customer’s expense. Campbell Scientific reserves the right to refuse service on products that were exposed to contaminants that may cause health or safety concerns for our employees.

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. General Description....................................................1
2. Specifications .............................................................1
3. Installation...................................................................2
4. Wiring........................................................................... 3
5. Example Programs .....................................................3
5.1 CR1000 Example Program...................................................................4
5.2 CR10X Example Program....................................................................5
6. Maintenance ................................................................9
Figures
3-1. SI-111 mounted onto a CM204 crossarm via the CM220....................2
3-2. SI-111 mounted onto a CM204 crossarm via the CM230....................2
Tables
5-1. Wiring for Example Programs .............................................................3
i
SI-111 Precision Infrared Radiometer
NOTE
Prior to November 2008, the SI-111 was named the IRR-P. Only the name changed.

1. General Description

The SI-111 is an infrared temperature sensor that provides a non-contact means of measuring the surface temperature of an object. It senses the infrared radiation being emitted by the target. The SI-111 can be widely used for measurements of leaf, canopy, and average surface temperature. With contact sensors, it is difficult to avoid influencing the temperature, maintain thermal contact, and provide a spatial average.
By mounting the infrared sensor at an appropriate distance from the target, it can be used to measure an individual leaf, a canopy, or any surface of interest.
The SI-111 is an infrared temperature sensor that includes a thermopile for measuring a millivolt output dependent on the target to sensor body temperature difference. A thermistor measures the temperature of the sensor body. The sensor body temperature is used to reference the target temperature.

2. Specifications

Input Power:
Absolute Accuracy:
Uniformity:
Repeatability:
Mass:
Dimensions:
Response Time:
Target Output Signal:
Body Temperature Output Signal:
Optics:
Wavelength Range:
Field of View:
Operating Environment:
2.5 V excitation for thermistor
*
±0.2°C @ –10° to 65°C ±0.5°C @ –40° to 70°C
±0.1°C @ –10° to 65°C ±0.3°C @ –40° to 70°C
±0.05°C @ –10° to 65°C ±0.1°C @ –40° to 70°C
190 grams
6.3 cm long by 2.3 cm diameter
Less than 1 second to changes in target temperature
60 μV per °C difference from sensor body
0 to 2500 mV
Germanium lens
8 to 14 micrometers
22° half angle
Highly water resistant, designed for continuous outdoor use; operating range is –55° to 80°C, 0 to 100% RH
**
*
Where target temperature is within 20°C of sensor body temperature.
**
Where target temperature is greater than 20°C of sensor body temperature.
1
SI-111 Precision Infrared Radiometer

3. Installation

The field of view for infrared sensors is calculated based on the geometry of the sensor and lens. However, optical and atmospheric scatter and unwanted reflections from outside the field of view may influence the measurement. Under typical conditions, 95 to 98 percent of the IR signal is from the field of view and 2 to 5 percent is from the area surrounding the field of view. If the target surface is small, for example a single leaf, try to mount the sensor close enough that the surface extends beyond the field of view.
NOTE
Remove green cap from the SI-111 before mounting to a crossarm, mast, or user-supplied support.
The SI-111 is often mounted to a CM202, CM204, or CM206 crossarm, a tripod or tower mast, or a user-supplied pole via a CM220 right angle mount (see FIGURE 3-1) or CM230 adjustable inclination mount. The CM230 allows the sensor to be pointed at the surface of interest. When using the CM230, fix the declination of the sensor by tightening the U-bolt that mounts on the mast or crossarm. The inclination is then adjusted with the other U-bolt and nuts (see FIGURE 3-2). A hole threaded for a standard tripod camera mount screw (1/4 inch diameter; 20 threads per inch) can be used to mount the sensor to a user-supplied support.
2
FIGURE 3-1. SI-111 mounted onto a CM204 crossarm via the CM220
FIGURE 3-2. SI-111 mounted onto a CM204 crossarm via the CM230

4. Wiring

g
SI-111 Precision Infrared Radiometer

5. Example Programs

The example datalogger programs measure the SI-111’s thermistor to obtain the SI-111 sensor body temperature and measure the SI-111’s thermopile to obtain the target-to-sensor body temperature difference.
After measuring the thermopile and thermistor outputs, the sensor body temperature is used to reference the target temperature.
Wiring for the example programs is shown in TABLE 5-1. The actual channels used need to be adjusted for the actual installation and application.
NOTE
Coefficients used to calculate the slope (m) and intercept (b) are specific to individual SI-111 sensors. The unique coefficients for each individual sensor are provided on the calibration sheet shipped with the sensor.
Target Temperature:
Red Differential High
Black Differential Low
Clear Analog Ground
Sensor Body Temperature:
Green Single-Ended
Blue Analog Ground
White Volta
e Excitation
TABLE 5-1. Wiring for Example Programs
Sensor/Lead Description CR10X CR1000
SI-111 Thermopile
Red Diff. High 2H 2H
Black Diff. Low 2L 2L
Clear Analog Ground AG
SI-111 Thermistor
Green SE 1 1
Blue Analog Ground AG
White Excitation E1
Target Temp
Sensor Temp
VX1 or EX1
3
SI-111 Precision Infrared Radiometer

5.1 CR1000 Example Program

This example CR1000 program measures the sensor every 5 seconds and outputs a sample once every 60 seconds. The actual measurement rate and output intervals need to be adjusted for the actual installation and application.
Explanation of Variables and Constants Used in the Program
PanelT = datalogger panel temperature BattV = datalogger battery voltage SBTempC = sensor body temperature in degrees Celsius SBTempK = sensor body temperature in Kelvin TargmV = mV output of thermopile infrared detector (dependent on temperature difference between
target and sensor body)
m = slope of equation relating target and sensor body temperatures to mV output of thermopile b = intercept of the equation relating target and sensor body temperatures to mV output of thermopile TargTempK = target temperature in Kelvin TargTempC = target temperature in degrees Celsius mC2 = polynomial coefficient (C2) used to calculate slope (m) mC1 = polynomial coefficient (C1) used to calculate slope (m) mC0 = polynomial coefficient (C0) used to calculate slope (m) bC2 = polynomial coefficient (C2) used to calculate intercept (b) bC1 = polynomial coefficient (C1) used to calculate intercept (b) bC0 = polynomial coefficient (C0) used to calculate intercept (b)
NOTE
All calibration coefficients are sensor-specific; those listed below are examples and must be changed based on the sensor being used.
'CR1000 Series Datalogger Program for Measuring Apogee Model SI-111 Infrared Radiometer
'Declare public variables Public PanelT, BattV, SBTempC, SBTempK, TargmV, m, b, TargTempK, TargTempC
'Declare constants (replace the listed values with coefficients received with sensor) Const mC2 = 82213 Const mC1 = 7841000 Const mC0 = 1419700000 Const bC2 = 13114 Const bC1 = 185020 Const bC0 = -17215000
'Define data table (table is outputting data every 60 seconds) DataTable (IRR,1,-1) DataInterval (0,60,Sec,10) Minimum (1,BattV,FP2,0,False) Sample (1,PanelT,FP2) Average (1,TargmV,FP2,False) Average (1,SBTempC,FP2,False) Average (1,TargTempC,FP2,False) EndTable
'Main program (program is making a measurement every 5 seconds) BeginProg Scan (5,Sec,0,0) PanelTemp (PanelT,_60Hz) Battery (BattV)
'Instruction to measure sensor body temperature (green wire to SE1, white wire to EX1, blue wire ‘to ground) Therm109 (SBTempC,1,1,Vx1,0,_60Hz,1.0,0)
4
SI-111 Precision Infrared Radiometer
'Instruction to measure mV output of thermopile detector (red wire to 2H, black wire to 2L, clear ‘wire to ground) VoltDiff (TargmV,1,mV2_5,2,True ,0,_60Hz,1.0,0)
'Calculation of m (slope) and b (intercept) coefficients for target temperature calculation m = mC2 * SBTempC^2 + mC1 * SBTempC + mC0 b = bC2 * SBTempC^2 + bC1 * SBTempC + bC0
'Calculation of target temperature SBTempK = SBTempC + 273.15 TargTempK = ((SBTempK^4) + m * TargmV + b)^0.25 TargTempC = TargTempK - 273.15
'Call output tables CallTable IRR NextScan EndProg

5.2 CR10X Example Program

This example CR10X program measures the sensor once a second and outputs the average values once an hour. The actual measurement rate and output intervals need to be adjusted for the actual installation and application.
Explanation of Labels Used in the Program
mV_thrm = mV output of the thermistor 1_mV_thrm = first step in converting the mV output of the thermistor to resistance 2_mV_thrm = second step in converting the mV output of the thermistor to resistance R_thrm = resistance of the thermistor InR_thrm = natural log of the resistance of the thermistor Scaled_R = intermediate step in converting the natural log of the resistance to temperature SH_Coeff = application of the Steinhart and Hart coefficients to convert the scaled resistance to the
reciprocal of temperature
SB_Temp_K = sensor body temperature in Kelvin SB_Temp_C = sensor body temperature in degrees Celsius mV_tpile = mV output of the thermopile (dependent on the temperature difference between the
target and the sensor body) m_slope = slope of the equation relating target and sensor body temperature to mV output of the thermopile b_inter = y-intercept of the equation relating target and sensor body temperature to mV output of the thermopile
Exponent1 = exponent used to raise the sensor body temperature to the 4th power Exponent2 = exponent used to calculate the 4th root of the sum of the terms used to calculate the
target temperature
1_SB_4Pow = first calculation step; sensor body temperature (Kelvin) raised to the fourth power 2_mVxm = second calculation step; mV output of the thermopile multiplied by m (slope) 3_Sum1 = third calculation step; sum of calculation steps one and two 4_Sum2 = fourth calculation step; the sum of calculation step 3 and b (intercept) T_Temp_K = target temperature in Kelvin; calculated by adding the temperature difference between
the target and sensor body to the sensor body temperature T_Temp_C = target temperature in degrees C
5
SI-111 Precision Infrared Radiometer
;{CR10X}
*Table 1 Program 01: 1 Execution Interval (seconds)
;Instruction string to measure the resistance of the thermistor and calculate the sensor body ;temperature. See the Instruction Manual for Campbell Scientific Model 109 Temperature Probe for ;details.
1: AC Half Bridge (P5) 1: 1 Reps 2: 25 2500 mV 60 Hz Rejection Range ;the range should at least match the excitation 3: 1 SE Channel 4: 1 Excite all reps w/Exchan 1 5: 2500 mV Excitation 6: 1 Loc [ mV_thrm ] 7: 1.0 Mult 8: 0.0 Offset
2: Z=1/X (P42) 1: 1 X Loc [ mV_thrm ] 2: 2 Z Loc [ 1_mV_thrm ]
3: Z=X+F (P34) 1: 2 X Loc [ 1_mV_thrm ] 2: -1.0 F 3: 3 Z Loc [ 2_mV_thrm ]
4: Z=X*F (P37) 1: 3 X Loc [ 2_mV_thrm ] 2: 24900 F 3: 4 Z Loc [ R_thrm ]
5: Z=LN(X) (P40) 1: 4 X Loc [ R_thrm ] 2: 5 Z Loc [ InR_thrm ]
6: Z=X*F (P37) 1: 5 X Loc [ InR_thrm ] 2: 0.001 F 3: 6 Z Loc [ Scaled_R ]
7: Polynomial (P55) 1: 1 Reps 2: 6 X Loc [ Scaled_R ] 3: 7 F(X) Loc [ SH_Coeffs ] 4: .001129 C0 5: .234108 C1 6: 0.0 C2 7: 87.7547 C3 8: 0.0 C4 9: 0.0 C5
8: Z=1/X (P42) 1: 7 X Loc [ SH_Coeffs ] 2: 8 Z Loc [ SB_Temp_K ]
6
SI-111 Precision Infrared Radiometer
9: Z=X+F (P34) 1: 8 X Loc [ SB_Temp_K ] 2: -273.15 F 3: 9 Z Loc [ SB_Temp_C ]
;Instruction to measure the mV output of the thermopile.
10: Volt (Diff) (P2) 1: 1 Reps 2: 21 2.5 mV 60 Hz Rejection Range 3: 2 DIFF Channel 4: 11 Loc [ mV_tpile ] 5: 1.0 Mult 6: 0.0 Offset
;Calculation of m (slope) coefficient for target temperature calculation. Each sensor has unique ;C0, C1, and C2 values. Refer to the calibration sheet shipped with the sensor to obtain the correct ;values for your sensor.
11: Polynomial (P55) 1: 1 Reps 2: 9 X Loc [ SB_Temp_C ] 3: 12 F(X) Loc [ m_slope ] 4: 15182.65 C0 5: 86.85177 C1 6: 0.69817 C2 7: 0.0 C3 8: 0.0 C4 9: 0.0 C5
12: Z=X*F (P37) 1: 12 X Loc [ m_slope ] 2: 99999 F 3: 12 Z Loc [ m_slope ]
;Calculation of b (intercept) coefficient for target calculation. Each sensor has unique C0, C1, and ;C2 values. Refer to the calibration sheet shipped with the sensor to obtain the correct values for ;your sensor.
13: Polynomial (P55) 1: 1 Reps 2: 9 X Loc [ SB_Temp_C ] 3: 13 F(X) Loc [ b_inter ] 4: -31.09271 C0 5: -2.95714 C1 6: 0.25154 C2 7: 0.0 C3 8: 0.0 C4 9: 0.0 C5
14: Z=X*F (P37) 1: 13 X Loc [ b_inter ] 2: 99999 F 3: 13 Z Loc [ b_inter ]
7
SI-111 Precision Infrared Radiometer
;Target temperature calculation based on m and b coefficients.
15: Z=F x 10^n (P30) 1: 0.4 F 2: 1 n, Exponent of 10 3: 14 Z Loc [ Exponent1 ]
16: Z=F x 10^n (P30) 1: 0.025 F 2: 1 n, Exponent of 10 3: 15 Z Loc [ Exponent2 ]
17: Z=X^Y (P47) 1: 8 X Loc [ SB_Temp_K ] 2: 14 Y Loc [ Exponent1 ] 3: 16 Z Loc [ 1_SB_4Pow ]
18: Z=X*Y (P36) 1: 11 X Loc [ mV_tpile ] 2: 12 Y Loc [ m_slope ] 3: 17 Z Loc [ 2_mVxm ]
19: Z=X+Y (P33) 1: 16 X Loc [ 1_SB_4Pow ] 2: 17 Y Loc [ 2_mVxm ] 3: 18 Z Loc [ 3_Sum1 ]
20: Z=X+Y (P33) 1: 13 X Loc [ b_inter ] 2: 18 Y Loc [ 3_Sum1 ] 3: 19 Z Loc [ 4_Sum2 ]
21: Z=X^Y (P47) 1: 19 X Loc [ 4_Sum2 ] 2: 15 Y Loc [ Exponent2 ] 3: 20 Z Loc [ T_Temp_K ]
22: Z=X+F (P34) 1: 20 X Loc [ T_Temp_K ] 2: -273.15 F 3: 21 Z Loc [T_Temp_C ]
;Output average values once an hour
23: If time is (P92) 1: 0 Minutes (seconds -- ) into a 2: 60 Interval (same units as above) 3: 10 Set Output Flag High (Flag 0)
24: Real Time (P77) 1: 1220 Year, Day, Hour/Minute (midnight = 2400)
25: Average (P71) 1: 1 Reps 2: 21 Loc [ T_Temp_C ]
8
*Table 2 Program 02: 0.0 Execution Interval (seconds)
*Table 3 Subroutines
End Program

6. Maintenance

A primary source of inaccurate measurements for any radiation sensor is blocking of the optical path to the detector. The window in the Apogee’s infrared sensor is inset and protected, but it can become partially blocked in three ways:
1. Spiders can make a nest in the entrance. We recommend using a cotton
2. Calcium deposits can accumulate on the window if irrigation water sprays
SI-111 Precision Infrared Radiometer
swab to apply a spider repellent around the entrance to the aperture (not on the sensor window itself).
up on the head. These typically leave a thin white film on the surface and can be removed with a dilute acid like vinegar. Calcium deposits cannot be removed with solvents such as alcohol or acetone.
3. Dust and dirt can be deposited in the aperture in windy environments and
are best cleaned with deionized water, rubbing alcohol, or in extreme cases, acetone.
Clean the inner threads and sensor window using a cotton swab dipped in the appropriate solvent. It is important to use only gentle pressure on the window to avoid scratching the thin optical coating on the window. Let the solvent do the cleaning, not mechanical force. The cleaning should be repeated with a second, fresh cotton swab to ensure a completely clean window. Sensors can go for many months and stay clean in some environments, but frequent cleaning is needed in other environments.
9
SI-111 Precision Infrared Radiometer
10

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 Scientific Australia Pty. Ltd. (CSA)
PO Box 8108
Garbutt Post Shop QLD 4814
AUSTRALIA
www.campbellsci.com.au • info@campbellsci.com.au
Campbell Scientific do Brasil Ltda. (CSB)
Rua Apinagés, nbr. 2018 ─ Perdizes
CEP: 01258-00 ─ São Paulo ─ SP
BRASIL
www.campbellsci.com.br • vendas@campbellsci.com.br
Campbell Scientific Canada Corp. (CSC)
11564 - 149th Street NW
Edmonton, Alberta T5M 1W7
CANADA
www.campbellsci.ca • dataloggers@campbellsci.ca
Campbell Scientific Centro Caribe S.A. (CSCC)
300 N Cementerio, Edificio Breller
Santo Domingo, Heredia 40305
COSTA RICA
www.campbellsci.cc • info@campbellsci.cc
Campbell Scientific Ltd. (CSL)
Campbell Park
80 Hathern Road
Shepshed, Loughborough LE12 9GX
UNITED KINGDOM
www.campbellsci.co.uk • sales@campbellsci.co.uk
Campbell Scientific Ltd. (France)
3 Avenue de la Division Leclerc
92160 ANTONY
FRANCE
www.campbellsci.fr • info@campbellsci.fr
Campbell Scientific Spain, S. L.
Avda. Pompeu Fabra 7-9, local 1
08024 Barcelona
SPAIN
www.campbellsci.es • info@campbellsci.es
Please visit www.campbellsci.com to obtain contact information for your local US or international representative.
Loading...
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use