Network Meter Block Installation, Operation, & Maintenance Manual
Monitoring and Configuring the NMB 24
4.3.3.2 Calibrating Analog Inputs
You can reduce inherent errors in the transducer from communicated values for analog channels. To
calibrate a new device (such as a pressure transmitter) or recalibrate existing devices attached to your
NMB, complete the following steps:
1. Select Basic I/O > Analog Calibration. The Scaled Value column displays real-time values for the
NMB’s power supply voltage, analog resistive temperature device (RTD) input channel, and analog
current input channels.
2. After determining the calibration standard RTD values and connecting the standard to the RTD input of
the device, complete the following steps in the RTO Value row:
a. Adjust the calibration standard to 50 to 60 ohms.
b. In the Span Count column, type the measured resistance value for Point 1 and then click P1.
c. Adjust the calibration standard to 190 to 200 ohms.
d. In the Span Count column, type the measured resistance value for Point 2 and then click P2.
e. Click Calibrate. The RTD’s gain and offset values are automatically updated and can be used to
validate the accuracy and precision of the calibration.
f. To save the newly calibrated gain and offset values, click Apply.
3. Complete the following steps in the 4-20 mA Input 1 row:
a. Source a 3.5 to 5.4 mA signal into the +Iin1 input on the NMB.
b. In the Span Count column, type the current value for Point 1 and then click P1.
c. Source a 19.5 to 20.5 mA signal into the +Iin1 input on the NMB.
d. In the Span Count column, type the current value for Point 2 and then click P2.
e. Click Calibrate. Input 1’s gain and offset values are automatically updated and can be used to val-
idate the accuracy and precision of the calibration.
f. To save the newly calibrated gain and offset values, click Apply.
4. Complete the following steps in the 4-20 mA Input 2 row:
a. Source a 3.5 to 5.4 mA signal into the +Iin2 input on the NMB.
b. In the Span Count column, type the current value for Point 1 and then click P1.
c. Source a 19.5 to 20.5 mA signal into the +Iin2 input on the NMB.
d. In the Span Count column, type the current value for Point 2 and then click P2.
e. Click Calibrate. The 4-20 mA Input 2’s gain and offset values are automatically updated and can
be used to validate the accuracy and precision of the calibration.
f. To save the newly calibrated gain and offset values, click Apply.
The NMB’s analog inputs are configured at the factory, but you can perform your own calibration on
site. At any time, you can revert to the factory-calibrated default values if needed (see Section 4.3.8:
Restoring Factory-Default Configuration Parameters).
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