CR1000 Manual - Campbell Scientific

Section 8. Operation
Resolution (p. 306) lists high resolution ranges available for various thermocouple
types and temperature ranges. The following four example calculations of
thermocouple input error demonstrate how the selected input voltage range
impacts the accuracy of measurements. Figure Input Error Calculation (p. 307)
shows from where various values are drawn to complete the calculations. See
Measurement Accuracy (p. 278) for more information on measurement accuracy and
accuracy calculations.
When the thermocouple measurement junction is in electrical contact with the
object being measured (or has the possibility of making contact) a differential
measurement should be made to avoid ground looping.
Table 65. Voltage Range for Maximum Thermocouple Resolution
Reference temperature at 20°C
TC Type and
Temperature
Range (°C)
Temperature
Range (°C)
for ±2.5 mV
Input Range
Temperature
Range (°C)
for ±7.5 mV
Input Range
Temperature
Range (°C)
for ±25 mV
Input Range
Temperature
Range (°C)
for ±250 mV
Input Range
T: -270 to 400 -45 to 75 -270 to 180 -270 to 400 not used
E: -270 to 1000 -20 to 60 -120 to 130 -270 to 365 >365
K: -270 to 1372 -40 to 80 -270 to 200 -270 to 620 >620
J: -210 to 1200 -25 to 65 -145 to 155 -210 to 475 >475
B: -0 to 1820 0 to 710 0 to 1265 0 to 1820 not used
R: -50 to 1768 -50 to 320 -50 to 770 -50 to 1768 not used
S: -50 to 1768 -50 to 330 -50 to 820 -50 to 1768 not used
N: -270 to 1300 -80 to 105 -270 to 260 -270 to 725 >725
306