9
6.1.5 Calibration example
A BA405C set point station is required to display
25.0 with a 4.000mA output and 115.0 with at
20.000mA output.
i.e.
A zero of positive 250
Ignoring decimal
point.
A span of 900
A dummy decimal point in position 00.0
The following adjustments are required:
Step 1
The BA405C is required to display a
positive zero therefore the
suppression / elevation links should be
put in the elevation position.
Step 2
The required zero is 250, therefore the
zero link should be put in the 0 to 500
position.
Step 3
The required span is 900, therefore the
span links should be placed in the 500 to
1000 position.
Step
4
A dummy decimal point is required
between the least two significant digits,
therefore the decimal point link should be
placed in the 00.0 position.
Step 5
Adjust the BA405C front panel control
until the output current measured by
external ammeter is 4.000mA. The zero
potentiometer at the rear of the BA405C
should then be adjusted until the
BA405C displays 25.0
Step 6
Adjust the BA405C front panel control
until the external current measured by an
external ammeter is 20.000mA. The
span potentiometer at the rear of the
BA405C should then be adjusted until
the BA405C displays 115.0
Step
7
Repeat steps 5 and 6 until both
calibration points are correct. The span
and zero controls are almost
independent so it should only be
necessary to repeat each adjustment
twice.
Fig 9 Position of calibration plug-in links and potentiometers
