Copyright 2013 Baker Hughes Company.
English–DPI
620G Instruction Manual | 73
Analysis
8. Documenting
This chapter describes the Documenting functions available with the DPI
620 Genii calibrator and
are as follows:
•
ANALYSIS
•
RUN PROCEDURE
8.1 Analysis
The Analysis function takes readings from two or more channels to calibrate the transfer
characteristic of the device being tested. One channel is the Reference channel and the other
channel is the Input channel.
The Reference channel:
•
Provides a measure of the input signal to the device.
•
If calibrating a temperature transmitter, the Reference channel could be CH1 in either RTD
or TC source mode.
•
If the device is a pressure transmitter, the Reference channel could be P1 or P2 measuring
the input pressure to the device or an external pressure channel e.g. IDOS.
The Input channel:
•
Measures the output signal from the device.
•
If calibrating a 4 to 20
mA process transmitter, it could be CH2 in Current Measure mode.
A second input channel can also be used, to calculate the transfer characteristic between three
points in the signal path and may be calibrated at the same time, as in the example that follows.
When calibrating a process transmitter that is HART® enabled the second input channel could
be the HART® channel. The HART® channel reads the Primary Variable (PV) value from the
sensor in the process transmitter. This allows the pressure sensor to be calibrated at the same
time as the current loop output.
Any active channel that is not defined as Reference is Input by default.
There must be one Reference channel and at least one Input channel defined for the Analysis
function set-up to be correct.
At each test point value, the Analysis function calculates the difference of each Input channel to
the ideal transfer characteristic and compares this to a tolerance limit.
This deviation is calculated and displayed as %Span or %Reading.
The tolerance test result is shown a Pass
or Fail
icon.
8.1.1 Setup
1. Set the DPI
620 Genii channels in the Calibrator function. Refer to Section
2. Connect the calibrator to the device under test.
3. Enter the Documenting function by tapping the icon
from the Dashboard.
4. Select ANALYSIS.
