Detcon FP-524D-HRT - Manual (Page 40)

Model FP-524D-HRT
FP-524D-HRT Instruction Manual Rev. 0.1 Page 36 of 48
100~250 Ohm
Resistor
FP-524D Connector
Board
Wiring to
LEL Sensor
+ 24V
DVM +mA
GND (- 24V)
DVM GND
Figure 20 DVM Connection
D/A Trim
1) Select “D/A trim” from the Loop test Calibrate section of the screen.
2) The procedure will prompt to connect a meter: (Refer to Figure 20.)
a) Disconnect the wire from the connector board mA terminal.
b) Connect one end of a 100~250Ohm resistor to the mA terminal.
c) Connect the positive lead of a DVM set to measure milliamps to the other end of the resistor.
d) Connect the negative lead (-) of the DVM to the ‘DC-’ terminal of the connector board.
3) The procedure will set the output to 4ma, and prompt for the DVM Reading. Input the reading and select
“OK”.
4) The HRT Bridge will readjust the output for 4mA, and inquire if the reading is 4mA on the DVM (select
“YES” or “NO”).
5) If the reading on the DVM is 4mA, select “YES” and “OK” and the HRT Bridge will continue on to
20mA. If the reading is not 4mA, select “NO” and “OK” and the procedure will re-run the 4mA
calibration (Step 3).
6) The procedure will set the output to 20mA, and prompt for the DVM Reading. Input the reading and
select “OK”.
7) The HRT Bridge will readjust the output for 20mA, and inquire if the reading is 20mA on the DVM
(select “YES” or “NO”).
8) If the reading on the DVM is 20mA, Select “YES” and “OK”. If the reading is not 20mA, select “NO”
and “OK” and the procedure will re-run the 20mA calibration (Step 6).
9) When both the 4mA and the 20mA have been calibrated the procedure will return the HRT Bridge to
automatic control.
Loop Test
1) Ensure that the DVM is connected as prescribed in Figure 20:
a) Disconnect the wire from the Connector Board mA terminal.
b) Connect one end of a 100~250Ohm resistor to the mA terminal on the connector board.
c) Connect the positive lead of a DVM, set to measure milliamps, to the other end of the resistor.
d) Connect the negative lead (-) of the DVM to the ‘DC-’ terminal of the connectorboard. (Figure 20)
2) Select “Loop test” from the Loop test Calibrate section of the screen.
3) The procedure will prompt for a setting (“4mA”, “20mA”, “Other”, and “End”).
4) Select one of the settings or “End” to exit.
5) If “Other” is selected, the procedure will prompt for a value. Only valid values will be accepted.
6) Select “OK”.
7) The HRT Bridge will set the output for the selected milliamp value.
8) Compare the reading on the DVM to the output displayed. Select “OK” when ready to continue