13
Calibration
Z(zero)
S(span)
Fig.2
Fig.1
SP98FA and SP96FA
Before the calibration of the unit is first tested,
the process should be free of pressure or (if
that is not possible) the unit should first be
tested outside of the vessel.
Make sure the muliti-meter is correctly
connected in series with the source and the
instrument. The scale should be set to mA
First confirm that the current output is at 4mA
(for SPFA units you can adjust the trimpot
"zero".) Turning the trimpot clockwise
increases the current value, and turning it
counterclockwise decreases the value
(Fig.2).
After adjusting (if necessary) the 4mA (zero)
install the unit in the process or fill the vessel
to increase the pressure of the process to the
maximum level desired. If necessary, turn the
trimpot (Span) to adjust the 20mA signal
(Fig. 3).
After calibrating the unit for the first time, it is
recommended that the you re-check the zero
and span ouput with your multimeter. This will
confirm that the unit is properly calibrated or if
further adjustment is necessary.
