Ametek Land 4500 MKIII, User Manual

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Opacity and Dust Monitor
User Guide
Model 4500 MkIII
B - 10
To configure the 4-20 mA current loop output:
1) From Settings , press
2) Use the and arrows to select Output Type and press
3) Use the and arrows to select Opacity , Optical Density
, Dust Density , Constant Current , Calibration Drift or
Pathlength Correction Factor and press
4) Press to return to Output Type.
5) Use the and arrows to select Output Range and press
6) Use the and arrows to change the output value corresponding to
20mA and press
7) Press to return to Output Range.
8) Use the and arrows to select Show Negative Values and press
9) Use the and arrows to select Show Negative Values or No
Negative Values and press
10) Press to return to Show Negative Values
If required, the current loop output can be set to deliver a constant
current for test purposes.
11) Use the and arrows to select Output Current and press
12) Use the and arrows to change the output current and press
13) When the test is complete, press to switch back to normal operation.
14) Press to return to Settings
Track and hold
The 4-20 mA current loop output can be set to track or hold during
calibration. This function is controlled using the following system parameters
Register 188 - transceiver output
Register 338 - AFU output 1
Register 351 - AFU output 2
Setting the register value = 1 allows the current loop to track during the
calibration check. This option is required for compliance applications so that
the calibration value can be recorded by the data acquisition system.
Setting the register value = 2 freezes the 4-20 mA current loop during
calibration, with the output held to the last valid measurement. This option is
appropriate where the signal is being used as part of a process control system
where the calibration reading could affect the operation of the controller.