Campbell Scientific CR10X Measurement and Control System - Manual (Page 140)

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-8
TABLE 9-4. Thermocouple Type Codes
Code Thermocouple Type
X1 T (copper - constantan) X = 0 Normal Measurement
X2 E (chromel - constantan) X = 8 TC input from A5B40 isolation
X3 K (chromel - alumel) (uses 5 V range)
X4 J (iron - constantan) X = 9 Output -99999 if out of common
X5 B (platinum - rhodium) mode range (Inst. 14 only)
X6 R (platinum - rhodium)
X7 S (platinum - rhodium)
X8 N (nickel - chromium)
TABLE 9-5. Voltage and Temperature Ranges for Thermocouples
if the Reference is 20
°°°°C
Voltage
Range
Type T Type E Type K Type J
±2.5 mV -46 to 78 -21 to 60 -44 to 80 -29 to 67
±7.5 mV
-270 to 181 -124 to 134 -270 to 203 -149 to 159
±25 mV
-270 to 400 -270 to 365 -270 to 620 -210 to 476
±250 mV −−−
-270 to 1000 -270 to 1372 -210 to 760
Voltage
Range
Type B Type R Type S Type N
±2.5 mV
0 to 709 0 to 158 -50 to 331 -80 to 108
±7.5 mV
0 to 1267 0 to 772 -50 to 824 -200 to 262
±25 mV
0 to 1700 0 to 1450 -50 to 1450 -200 to 725
±250 mV −−− −−− −−−
-200 to 1300
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Range code (Table 9-5,
9-1)
03: 2 Single-ended channel
number for first TC
(when indexed (--),
becomes an input
location containing
voltage measurement)
04: 2 TC type code (Table
9-4)
05: 4 Reference temperature
location
06: 4 Input location number
07: FP Multiplier
08: FP Offset
Input locations altered: 1 per repetition
*** 14 THERMOCOUPLE TEMPERATURE, ***
DIFFERENTIAL MEASUREMENT
FUNCTION
This instruction calculates the thermocouple
temperature for the thermocouple type selected.
The instruction specifies a DIFFERENTIAL
VOLTAGE MEASUREMENT (Section 13.2) on
the thermocouple, adds the measured voltage
to the voltage calculated for the reference
temperature relative to 0°C, and converts the
combined voltage to temperature in °C. A
multiplier of 1 and an offset of zero yields
temperature in degrees Celsius.
The differential inputs are briefly shorted to
ground prior to making the voltage
measurement to insure that they are within the
common mode range. Table 9-4 gives the
thermocouple type codes for Parameter 4.
Enter a 9 in front of the code and the CR10X
will make an additional check on common mode
range; -99999 is output for temperature if
common mode range is exceeded.