Calibration - ICP DAS USA I-7021 User Manual

1.10 Calibration

Warning: It is not recommended that calibration be
performed until the process is fully understood.
I-7021/21P Current Output Calibration
1. Set the jumper JP1 to select internal power and connect
a current meter to the current output terminal of the
module. If there is no current meter then you can use a
voltage meter with a shunt resistor of 250 ohm and
0.1%. The current (I) can be calculated using the
equation, I = V (voltage) / 250.
2. Warm up the module for at least 30 minutes.
3. Set the type code to 30, 0 ~ 20 mA. Refer to Section
2.1 for details.
4. Send command to output 4 mA. Refer to Section. 2.2
for details.
5. Repeat to send the trim command and check the meter
until the meter's reading is nearest to 4 mA. Refer to
Section 2.10 for details of sending the trim command.
6. Send the 4 mA calibration command. Refer to Section
2.5 for details.
7. Send command to output 20 mA. Refer to Section. 2.2
for details.
8. Repeat to send the trim command and check the meter
until the meter's reading is nearest to 20 mA. Refer to
Section 2.10 for details of sending the trim command.
9. Send the 20 mA calibration command. Refer to
Sections 2.7 for details.
I-7021/22/24, M-7022/24/28 User Manual, Rev: B2.3 27