Dynisco TX180, Installation And Operation Manual

Page: 37 / 52

TX180 Temperature Transmitter 37
Trimming of the 20.0mA current limit is done in exactly the same manner as was described for
trimming the 4.0mA point. Similarly the same precautions apply. The code 9701 corresponds to
selecting the function to raising the mA output. The code 9702 corresponds to selecting the function
to lower the mA output. The code 9710 confirms raising the 20mA output by approximately 3.5
micro-ampere increments with each push of the
NEXT
key. The code 9720 confirms lowering the
20mA output by approximately 3.5 micro-ampere increments with each push of the
NEXT
key.
After completing the trim 20.0mA pressing the
NEXT
key brings up the
TRIM DISPLAY
menu.
5.11 T
RIM
D
ISPLAY
The display trim allows the display to be trimmed to a desired point. The transmitter’s LI-1 display
will show its value based upon the transmitter’s current settings. It is often desirable to alter the
display to make the display agree with another instrument at a critical measurement point. If this is
desirable, the display can be trimmed. The display trim operates as a zero shift and shifts the display
readings by the same amount at every point.
You can enter a single point offset to the display. Be certain before making a display trim correction
that you have made good electrical connections to the transmitter and the sensor. In the 2 or 3 wire
RTD input, or thermocouple input modes, it is possible to produce an error of a few degrees with a
fraction of an ohm in any one of the connections. Please be careful when tightening down the input
connections. These can be easily broken if a lot of torque is applied. The idea is to make a good
electrical connection without breaking the connections.
The display trim allows you to enter an offset correction. For example, suppose that the display reads
530
°
F, at a time when an external device that you want to agree with reads 525
°
F. You would then
want to enter a -5
°
F offset in the display trim. This is done exactly the same way as setting the zero
and full-scale values. Pressing the
NEXT
key at this point advances the menus and the display will
now read:
The 9800 code corresponds to the display trim.
One can set the display trim offset by pressing the
ENTER
key. The display changes to
The 9801 code indicates that a “plus” number is selected for the display offset. By repeatedly
pressing the
NEXT
key the display will alternate
9800
9801
9801 9802