www.miinet.com
Moore Industries-International, Inc.
- 25 -
User’s Manual
238-760-00K
May 2019
Functional Safety Dual Input Smart HART® Temperature Transmitter
STZ
Figure 2.12.
Custom Calibration/AO Loop Current Test/Trim
Select the Custom Calibration/AO Loop Current Test/Trim option in the configuration menu as
shown in Figure 2.12.
The points that will be used for trimming will be the “AO Zero” and the “AO Full” that were
configured earlier. For my example these two points will be 4mA (AO Zero) and 20mA (AO Full).
In the “Output Trim” section of the Parameter screen Set Output to “Lower Output Range”. This
will set the instrument’s output to 4mA. Use your voltmeter to read the voltage drop across the
250Ω resistor and calculate the actual current going through the resistor.
Example: A voltage reading of 1.08v equates to 4.32mA (1.08V ÷ 250Ω = 4.32mA). Enter this
value in the Measured Output Current box and then push the “Trim” button.
Now, select the “Upper Output Range”. This will set the instrument’s output to 20mA. Use your
voltmeter to read the voltage drop across the 250Ω resistor and calculate the actual current
going through the resistor.
Example: A voltage reading of 4.91v equates to 19.64mA (4.91V ÷ 250Ω = 19.64mA). Enter
this value in the Measured Output Current box and then push the “Trim” button.
Now that the 2-point output trimming has been done you can test the results by entering an
output value in the “Set Current to” box. Enter 4 (for 4mA) in the box, select the “Set” button and
the instrument’s output will go to 4mA and you can check for a 1V reading across the resistor.
You can then enter 20 and check for a 5V reading across the resistor.
There is no need to press the “Apply” button as all trim changes take immediate effect.
Note:
When complete BE SURE to press the “Clear” button to return control of the output back
to your STZ.
SECTION 2
