Chemtrac HydroAct 4, User Manual

Page: 56 / 77

56 Chapter 4. Outputs
4.1.3 Commissioning
When cables attach to analog outputs the instrument is forced to drive into different resistances. This
can result in the analog range being slightly affected. For example a 4-20mA output at the analyzer
could end up being 3.95mA to 19.9mA at the end of the cable. The HydroAct 4 has the capability
to drive more or less current to account for this resistance so that the analog output is exactly that
required at the end of the cable. This is achieved by calibrating the zero (offset) and span (top of the
scale) of the analog output.
4.1.3.1 Calibrate Offset
This configuration screen is accessed by navigating via the Options Menu:
Options → Maintenance → Calibrate Offset
Select the slider and then use the Left and Right buttons to adjust the zero.
4.1.3.2 Calibrate Span
This configuration screen is accessed by navigating via the Options Menu:
Options
→
Maintenance
→
Calibrate Span
Select the slider and then use the Left and Right buttons to adjust the span.
4.1.4 Operation
To access the analog output setup and maintenance options, select the relevant device tile in the main
menu and press “Select”. The output setup screen will be displayed initially, though other functions are
available by pressing the “Options” button.