10
4.
SETTING UP PROCEDURE.
4.1
Bipolar or Half-stroke Applications
1.
Connect the transducer and supply as shown in Section 2.
2.
Select the relevant gain range by setting the Coarse Span switch as shown
in Section 3.4. Refer also to the transducer data to determine the input
signal.
3.
Set Zero Input lever to ON, all other Zero levers to OFF.
4.
Adjust Fine Zero potentiometer for 12mA output.
5.
Reset Zero Input lever to OFF and adjust the transducer armature for 12mA
output. This determines the transducer centre stroke position.
6.
Move the armature to the required full-scale position and adjust Fine Span
for 20mA output. (Note: primary or secondary connections may be reversed
to reverse the output polarity.)
7.
Move the armature to the required zero position (an equal but opposite
displacement to that in step 6) and check the output is 4mA. Trim Fine Span
and zero if necessary for optimum linearity over the 4-20mA range.
4.2
Offset Stroke Applications
1.
Carry out steps 1 to 5 in Section 4.1, then: -
2.
Move the armature to the desired half-stroke position and use the Coarse
Zero switch to suppress the output to near 12mA (refer to Section 3.1). Trim
for exactly 12mA via Fine Zero.
3.
Move the armature to the desired full-scale position and adjust Fine Span for
20mA output.
4.
Repeat steps 2 and 3 for consistent results.
5.
Move the armature to the desired 4mA position and check for 4mA output.
