Campbell 105T User manual

MODEL 105T THERMOCOUPLE PROBE
INSTRUCTION MANUAL
PRELIMINARY: 31/01/99
COPYRIGHT (c) 1999 CAMPBELL SCIENTIFIC, INC.

WARRANTY AND ASSISTANCE
The MODEL 105T THERMOCOUPLE PROBE is warranted by CAMPBELL SCIENTIFIC
(CANADA) CORP. (“CSC”) 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. CSC's obligation under this warranty is limited to repairing or replacing (at CSC's
option) defective products. The customer shall assume all costs of removing, reinstalling,
and shipping defective products to CSC. CSC will return such products by surface carrier
prepaid. This warranty shall not apply to any CSC 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. CSC is not liable for special, indirect, incidental, or
consequential damages.
Products may not be returned without prior authorization. To obtain a Return Merchandise
Authorization (RMA), contact CAMPBELL SCIENTIFIC (CANADA) CORP., at (780) 454-
2505. An RMA number will be issued in order to facilitate Repair Personnel in identifying
an instrument upon arrival. Please write this number clearly on the outside of the shipping
container. Include description of symptoms and all pertinent details.
CAMPBELL SCIENTIFIC (CANADA) CORP. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a purchase order to
cover repair costs.

1
MODEL 105T
THERMOCOUPLE PROBE
1. GENERAL DESCRIPTION
The Model 105T Thermocouple Probe is used
for monitoring the temperature of water or soil.
The 105T is a type T thermocouple consisting
of two wires of dissimilar metals (copper/
constantan) joined at one end. The output
voltage of the thermocouple is a function of this
junction temperature. The -L option on the
Model 105T Thermocouple Probe (105T-L)
indicates that the cable length is user specified.
2. SPECIFICATIONS
Probe
ANSI Thermocouple Type T
Temperature Range up to 50°C
Seebeck Coef 38 µV/°C @ 0°C
Interchangeability -73°C ±0.365°C
20°C ±0.1°C
50°C ±0.25°C
Cable
Conductors 24 AWG
Blue + (Copper)
Red - (Constantan)
Clear Shield
Insulation Extruded TPR
Jacket Extruded TPR
Diameter 0.2 inches
3. INSTALLATION
The 105T is designed for burial in soils or
submersion in water up to 50 feet.
4. WIRING
Connection to Campbell Scientific dataloggers
are given in Tables 1 and 2. Because of the
very small voltage levels, it is recommended
that the 105T be measured differentially.
FIGURE 1. 105T Probe to Datalogger Connections
Blue + Copper
Red - Constantan
Clear Shield

MODEL 105T THERMOCOUPLE PROBE
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TABLE 1. Generic Datalogger Connections for Single-Ended Measurements
TABLE 2. Generic Datalogger Connections for Differential Measurements
5. SAMPLE PROGRAM
This section is for users who write their own
datalogger programs. A datalogger program
for measuring 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. The CR510
Datalogger does not support thermocouple
measurements.
Programming instructions P13 or P14 are used
to measure the voltage of the 105T and convert
it to temperature using the equation for a type
T thermocouple. This equation assumes that
the termination point of the thermocouple
(wiring panel) is at 0°C. Because this is not the
case, we need to obtain the wiring panel
temperature in order to calculate the
temperature of the 105T. There is a thermistor
already located in the wiring panel of the
CR23X, 21X, and CR7 for this purpose.
For the CR10(X) the wiring panel temperature
must be measured using a Thermocouple
Reference Thermistor (CR10XTCR or
CR10TCR). When installed on the CR10(X),
the reference thermistor should lie between the
two analog input terminal strips.
Example 1 program illustrates programming for
the CR10(X) using instruction P11 to measure
the Reference Thermistor and instruction P14
to make a differential measurement of the
105T. Example 2 demonstrates programming
for the CR23X using P17 and P14. Refer to the
datalogger manual under Programming
Instructions P13 and P14 thermocouple
measurements.
For applications including a multiplexer
(AM416, AM16/32, or AM25T), please refer to
the appropriate multiplexer manual.
Description Color CR10(X) CR23X, 21X, CR7
+ Copper Blue Single-Ended Input Single-Ended Input
- Constantan Red AG
Shield Clear G
Description Color CR10(X) CR23X, 21X, CR7
+ Copper Blue Differential Input (H) Differential Input (H)
- Constantan Red Differential Input (L) Differential Input (L)
Shield Clear G

MODEL 105T THERMOCOUPLE PROBE
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Example 1. Sample CR10(X) Program using differential measurement instruction
TABLE 3. CR10XTCR or CR10TCR Wiring
Description Color CR10(X)
Signal Red SE 1 (1H)
Excitation Black E3
Signal Reference Clear AG
TABLE 4. 105T-L Wiring for Example 1
Description Color CR10(X)
+ Copper Blue 2H
- Constantan Red 2L
Shield Clear G
;Measure the temperature of the wiring panel on the CR10(X) using the CR10XTCR or CR10TCR.
;This instruction must proceed the measurement of the 105T.
1: Temp (107) (P11)
1: 1 Reps
2: 1 SE Channel
3: 3 Ex Channel Option
4: 1 Loc [ Ref_Temp ]
5: 1.0 Mult
6: 0.0 Offset
;Knowing the wiring panel temperature, we now measure the 105T voltage and use the type T
;equation to calculate the 105T temperature. A multiplier of 1 and offset of 0 yield the
;temperature in °C in input location 2 (TC_Temp).
2: Thermocouple Temp (DIFF) (P14)
1: 1 Reps
2: 21 2.5 mV 60 Hz Rejection Range
3: 2 DIFF Channel
4: 1 Type T (Copper-Constantan)
5: 1 Ref Temp (Deg. C) Loc [ Ref_Temp ]
6: 2 Loc [ TC_Temp ]
7: 1.0 Mult
8: 0.0 Offset
Example 2. Sample CR23X Program Using Differential Measurement Instruction
TABLE 5. 105T-L wiring for Example 2
Description Color CR23X
+ Copper Blue 1H
- Constantan Red 1L
Shield Clear
;Measure the temperature of the wiring panel on the CR23X.
;This instruction must proceed the measurement of the 105T.
1: Panel Temperature (P17)
1: 1 Loc [ Ref_Temp ]

MODEL 105T THERMOCOUPLE PROBE
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;Knowing the wiring panel temperature, we now measure the 105T voltage and use the type T
;equation to calculate the 105T temperature. A multiplier of 1 and offset of 0 yield the
;temperature in °C in input location 2 (TC_Temp).
2: Thermocouple Temp (DIFF) (P14)
1: 1 Reps
2: 21 10 mV, 60 Hz Reject, Slow Range
3: 1 DIFF Channel
4: 1 Type T (Copper-Constantan)
5: 1 Ref Temp (Deg. C) Loc [ Ref_Temp ]
6: 2 Loc [ TC_Temp ]
7: 1.0 Mult
8: 0.0 Offset