Hach ORBISPHERE 51 Series User Manual page 71

Inputs/Outputs Menu
Analog outputs (continued)
Calibration of the analog
output
Direct test
Characteristics test
70
The calibration of the analog output is aimed at aligning the internally
calculated current to the real current output. This was performed at factory,
but could become necessary again because of electronic tolerances. A
precision amperometer (or voltmeter for the voltage versions) connected at
the corresponding analog output connection point is required. Refer to
Measurement board on page
• Select the analog output channel to calibrate and press the Start button.
• Measure with the amperometer the current value for point 1. It should be
below 4 mA
• Edit point 1 and enter the same value as read on the amperometer, then
press the Continue button.
• Measure with the amperometer the current value for point 2. It should be
above 20 mA.
• Edit point 2 and enter the same value as read on the amperometer,
before pressing the Continue button.
Calibration of the selected analog output channel is completed. Proceed in
the same way for the other analog output channels available.
Test to check the calibration of the analog outputs. A precision amperometer
connected at the analog output connection point is required.
• Select a value (4, 12, 20 mA available) for each channel and compare
this value (+ 0.02 mA) with what the amperometer shows.
A calibration is required if the value on the amperometer differs from the
current selected + 0.02 mA).
Note: It is possible to test one analog output without interfering with the
others. During the test, the other analog outputs will continue to indicate the
measurement.
This is a test for the correct operation of the peripherals connected to each
analog output, by verifying that the PLC computes the correct value.
The analog output will send the current corresponding to the value entered
in the text boxes.
• Type in a test value for each analog output, and check for the related
action on the peripheral.
31.