Campbell 107 User manual

MODEL 107 TEMPERATURE PROBE
INSTRUCTION MANUAL
REVISION: 4/03
COPYRIGHT (c) 1983-2003 CAMPBELL SCIENTIFIC, INC.

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Warranty and Assistance
The MODEL 107 TEMPERATURE PROBE 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. The customer
shall assume all costs of removing, reinstalling, and shipping defective products
to CAMPBELL SCIENTIFIC, INC. CAMPBELL SCIENTIFIC, INC. will
return such products by surface carrier prepaid. This warranty shall not apply
to any CAMPBELL SCIENTIFIC, INC. products which have been subjected to
modification, misuse, neglect, accidents of nature, or shipping damage. This
warranty is in lieu of all other warranties, expressed or implied, including
warranties of merchantability or fitness for a particular purpose. CAMPBELL
SCIENTIFIC, INC. is not liable for special, indirect, incidental, or
consequential damages.
Products may not be returned without prior authorization. To obtain a
Returned Materials Authorization (RMA), contact CAMPBELL SCIENTIFIC,
INC., phone [phone]. 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
CAMPBELL SCIENTIFIC, INC. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a
purchase order to cover the repair.
815 W. 1800 N.
Logan, UT 84321-1784
USA
Phone [phone]
FAX [phone]
www.campbellsci.com
Campbell Scientific Canada Corp.
11564 -149th Street
Edmonton, Alberta T5M 1W7
CANADA
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Campbell Park
80 Hathern Road
Shepshed, Loughborough
LE12 9GX, U.K.
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FAX [phone]

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1
Model 107 Temperature Probe
1. General
The 107 Temperature Probe uses a thermistor to measure temperature. Custom
lead lengths are available up to 1000 ft.
The 107 Temperature Probe is designed for measuring air/soil/water
temperatures. For air temperature, a 41303 radiation shield is used to mount
the 107 Probe and limit solar radiation loading. The probe is designed to be
buried or submerged in water to 50’ (21 ps).
1.1 Specifications
Temperature
Measurement Range: -35°to +50°C
Thermistor Inter-
changeability Error: Typically <±0.2°C over 0°C to 60°C; ±0.4 @ -35°C
Temperature
Survival Range: -50°C to +100°C
Polynomial
Linearization Error: <±0.5°C over -35°C to +50°C
Time Constant
In Air: Between 30 and 60 seconds in a wind speed of 5 m s-1
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.
2. Accuracy
The overall probe accuracy is a combination of the thermistor's interchangeability
specification, the precision of the bridge resistors, and the polynomial error. In a
"worst case" all errors add to an accuracy of ±0.4°C over the range of -24°to 48°C
and ±0.9°C over the range of -38°C to 53°C. The major error component is the
interchangeability specification of the thermistor, tabulated in Table 2-1. For the
range of 0°to 50°C the interchangeability error is predominantly offset and can be
determined with a single point calibration. Compensation can then be done with an
offset entered in the measurement instruction. The bridge resistors are 0.1%
tolerance with a 10 ppm temperature coefficient. Polynomial errors are tabulated in
Table 2-2 and plotted in Figure 2-1.
NOTE

Model 107 Temperature Probe
2
TABLE 2-1. Thermistor
Interchangeability Specification
Temperature (°C)
Temperature
Tolerance (±°C)
−40 0.40
−30 0.40
−20 0.32
−10 0.25
0 to +50 0.20
TABLE 2-2. Polynomial Error
-40 to +56 <±1.0°C
-38 to +53 <±0.5°C
-24 to +48 <±0.1°C
FIGURE 2-1. Error Produced by Polynomial Fit to Published Values
3. Installation and Wiring
For air temperature measurement, the 107 must be housed inside a radiation
shield when used outdoors. The 41303 Radiation Shield (see Figure 3-1)
mounts to a CM6 or CM10 tripod. The UT018 mounting arm and UT6P
Radiation Shield mount to a UT30 tower.
The standard lead length of 6 feet and 9 feet allow the 107 to be mounted at a 2
meter height on the CM6/CM10 tripod or the UT30 tower respectively.
Connections to the datalogger for the 107 are shown in Figure 3-2 and
Table 3-1.

Model 107 Temperature Probe
3
The number of 107 probes per excitation channel is physically limited by the
number of lead wires that can be inserted into a single excitation terminal
(approximately 6).
FIGURE 3-1. 107 and 41303 Radiation Shield on a
CM6/CM10 Tripod Mast

Model 107 Temperature Probe
4
FIGURE 3-2. 107 Probe Datalogger Connections
TABLE 3-1. Sensor Wiring
Color Function CR10(X), CR510 21X, CR7,CR23X
Black Excitation Switched Excitation Switched Excitation
Red Signal Single-Ended Channel Single-Ended Channel
Purple Signal Ground AG
Clear Shield G
4. Programming
This section is for users who write their own datalogger programs. A
datalogger program to measure this sensor can be created using Campbell
Scientific’s Short Cut Program Builder software. You do not need to read this
section to use Short Cut.
Instruction 11 is used to measure temperature. Instruction 11 provides AC
excitation, makes a single ended voltage measurement, and calculates
temperature with a fifth order polynomial. A multiplier of 1.0 and an offset of
0.0 yields temperature in Celsius. For Fahrenheit, use a multiplier of 1.8 and an
offset of 32.
TABLE 4-1. Wiring for Example Program
Color Function CR10(X)
Black Excitation Switched Ex Channel 3
Red Signal Single-Ended Channel 9
Purple Signal Ground AG
Clear Shield G
Black
Red
Purple
Clea
r
Excitatio
n
Temp. Signal
Signal Ground
Shield

Model 107 Temperature Probe
5
Example 1. Sample Program
1: Temp (107) (P11)
1: 1 Reps
2: 9 SE Channel
3: 3 Excite all reps w/E3
4: 1 Loc [ Air_Temp ]
5: 1.0 Mult
6: 0.0 Offset
Excitation/Integration Codes
Code Result
0x excite all rep with channel x
1x increment chan x with each rep
2x excite all reps with channel x, 60 Hz rejection, 10 ms delay
3x excite all reps with channel x, 50 Hz rejection, 10 ms delay
4x increment chan x with each rep, 60 Hz rejection, 10 ms delay
5x increment chan x with each rep, 50 Hz rejection, 10 ms delay
5. Maintenance and Calibration
The 107 Probe requires minimal maintenance. Check monthly to make sure the
radiation shield is free from debris.
For most applications it is unnecessary to calibrate the 107 to eliminate the
thermistor offset. However, for those users that are interested, the following
briefly describes calibrating the 107 probes.
A single point calibration can be performed to determine the 107 temperature
offset (thermistor interchangeability). This calibration will not remove the
polynomial error. The value of the offset must be chosen so that the probe
outputs the temperature calculated by the polynomial, not the actual calibration
temperature. For example, a 107 is placed in a calibration chamber that is at 0°C
and the probe outputs 0.1°C. The offset is -0.16, because at 0°C the polynomial
calculates a temperature of -0.06°C (Table 6-1).
6. Instruction 11 Details
Understanding the details in this section are not necessary for general operation
of the 107 Probe with CSI's dataloggers.
Instruction 11 outputs a precise 2 VAC excitation (4 V with the 21X) and
measures the voltage drop due to the sensor resistance (Figure 6-1). The
thermistor resistance changes with temperature. Instruction 11 calculates the
ratio of voltage measured to excitation voltage (Vs/Vx) which is related to
resistance, as shown below:
Vs/Vx = 1000/(Rs+249000+1000)
where Rs is the resistance of the thermistor.
See the measurement section of the datalogger manual for more information on
bridge measurements.
Instruction 11 then calculates temperature using a fifth order polynomial equation
correlating Vs/Vx with temperature. The polynomial coefficients are given in
Table 6-2. The polynomial input is (Vs/Vx)*800. Resistance and datalogger
output at several temperatures are shown in Table 6-1.

Model 107 Temperature Probe
6
TABLE 6-1. Temperature, Resistance,
and Datalogger Output
Temperature °C Resistance OHMS Output °C
-40.00 4067212 -39.18
-38.00 3543286 -37.55
-36.00 3092416 -35.83
-34.00 2703671 -34.02
-32.00 2367900 -32.13
-30.00 2077394 -30.18
-28.00 1825568 -28.19
-26.00 1606911 -26.15
-24.00 1416745 -24.11
-22.00 1251079 -22.05
-20.00 1106485 -20.00
-18.00 980100 -17.97
-16.00 869458 -15.95
-14.00 772463 -13.96
-12.00 687276 -11.97
-10.00 612366 -10.00
-8.00 546376 -8.02
-6.00 488178 -6.05
-4.00 436773 -4.06
-2.00 391294 -2.07
0.00 351017 -0.06
2.00 315288 1.96
4.00 283558 3.99
6.00 255337 6.02
8.00 230210 8.04
10.00 207807 10.06
12.00 187803 12.07
14.00 169924 14.06
16.00 153923 16.05
18.00 139588 18.02
20.00 126729 19.99
22.00 115179 21.97
24.00 104796 23.95
26.00 95449 25.94
28.00 87026 27.93
30.00 79428 29.95
32.00 72567 31.97
34.00 66365 33.99
36.00 60752 36.02
38.00 55668 38.05
40.00 51058 40.07
42.00 46873 42.07
44.00 43071 44.05
46.00 39613 46.00
48.00 36465 47.91
50.00 33598 49.77
52.00 30983 51.59
54.00 28595 53.35
56.00 26413 55.05
58.00 24419 56.70
60.00 22593 58.28

Model 107 Temperature Probe
7
FIGURE 6-1. 107 Thermistor Probe Schematic
TABLE 6-2. Polynomial Coefficients
Coefficient Value
C0 -53.4601
C1 90.807
C2 -83.257
C3 52.283
C4 -16.723
C5 2.211
7. Electrically Noisy Environments
AC power lines can be the source of electrical noise. If the datalogger is in an
electronically noisy environment, the 107 temperature measurement should be
measured with 60 Hz rejection. Sixty and 50 Hz rejection is available as an
option in the Excitation Channel parameter of Instruction 11 for the CR10X,
CR510, and CR23X dataloggers. For the CR10, CR21X and CR7, the 107
should be measured with the AC half bridge (Instruction 5).
Example 2. Sample CR10(X) Instructions Using AC Half Bridge
1: AC Half Bridge (P5)
1: 1 Reps
2: 22 7.5 mV 60 Hz Rejection Range
3: 9 SE Channel
4: 3 Excite all reps w/Exchan 3
5: 2000 mV Excitation ;Use 4000 mV on 21X and CR7
6: 1 Loc [ Air_Temp ]
7: 800 Mult
8: 0 Offset

Model 107 Temperature Probe
8
2: Polynomial (P55)
1: 1 Reps
2: 1 X Loc [ Air_Temp ]
3: 1 F(X) Loc [ Air_Temp ]
4: -53.46 C0
5: 90.807 C1
6: -83.257 C2
7: 52.283 C3
8: -16.723 C4
9: 2.211 C5
8. Long Lead Lengths
The 60 and 50 Hz rejection options for the CR10X, CR510, and CR23X
include a delay to accommodate long lead lengths. For the CR10, 21X, and
CR7, if the 107 has lead lengths of more than 300 feet, use the DC Half Bridge
instruction (Instruction 4) with a 2 millisecond delay to measure temperature.
The delay provides a longer settling time before the measurement is made. Do
not use the 107 with long lead lengths in an electrically noisy environment.
Example 3. Sample Program CR10 Using DC Half Bridge with Delay
1: Excite-Delay (SE) (P4)
1: 1 Reps
2: 2 7.5 mV Slow Range
3: 9 SE Channel
4: 3 Excite all reps w/Exchan 3
5: 2 Delay (units 0.01 sec)
6: 2000 mV Excitation ;Use 4000 mV on 21X and CR7
7: 1 Loc [ Air_Temp ]
8: .4 Mult ;Use 0.2 on 21X and CR7
9: 0 Offset
2: Polynomial (P55)
1: 1 Reps
2: 1 X Loc [ Air_Temp ]
3: 1 F(X) Loc [ Air_Temp ]
4: -53.46 C0
5: 90.807 C1
6: -83.257 C2
7: 52.283 C3
8: -16.723 C4
9: 2.211 C5