Chapter 8. Servicing the PT878
174 Transport® Model PT878 Portable Liquid Flowmeter User’s Manual
8.7 Calibrating the Analog Output and Inputs
The Calibration option allows you to calibrate the analog output and inputs.
To enter the option, scroll to the Calibrate entry on the Service Menu and
press [ENTER]. The screen appears similar to Figure 117 below.
Figure 117: Outputs Window in the Calibration Option
8.7.1 Calibrating the Analog Output
The calibration procedure consists of calibrating the analog output zero
point (0 or 4 mA) and then calibrating the full scale point (20 mA). You
enter, first the setpoint, and then the actual value derived from an ammeter
or digital voltmeter. The analog outputs have a resolution of ±5.0 µA. Press
the [T] arrow key to enter the Analog Output window.
Analog Output
Calibrate/Test I/O
Analog Input
Setpoint
Cancel OK
mA
4
Calibrate
Actual 4
4 mA 20 mA
Actual 20 mA
Reset
20