Product Specifications | 4 |
With zeroing, the offset errors from the DAQ and the U2802A can be removed, and replaced with the zeroing error.
Based on the ITS- 90 Thermocouple table, a J- type thermocouple will output 33.102 mV at 600 °C, and changes at a rate of approximately 59 µV/°C. This corresponds to (33.102 mV × 97.673) or 3.2332 V at the input of the DAQ.
Hence, EDAQ, ESIG_COND, and EZEROING are calculated as follows:
•EDAQ
=0.02% × 33.102 mV
=6.62 µV
=6.62 µV ÷ 59 µV/°C
=0.112 °C
•ESIG_COND
=(0.06% × 33.102 mV) ÷ 59 µV/ °C
=0.337 °C
•EZEROING
=6 µV ÷ 59 µV/°C
=0.102 °C
Next, the cold junction sensor error is calculated.
At 23 °C, a J- type thermocouple output voltage changes at a rate of 52 µV/ °C. Thus, the CJ sensor error of 1 °C at 23 °C corresponds to 52uV/ °C × 1°C = 52 µV.
At 600 °C,
•ECJC
=52 µV ÷ 59 µV/°C
=0.88 °C
Agilent U2802A | 55 |
