-18-
(3) For models other than COMM-less models
b. Set the MNT switch to the center position for normal operation mode.
Oxygen sensor: COS-7 (FS: 50vol%)
Toxic gas sensor: CDS-7
Combustible gas sensor: CHS-7
Oxygen sensor: COS-7 (FS: 25vol%)
a. Measure the analog output (current)
between the ―G‖ and ―H‖ terminals with
a multimeter, etc. If the output level is
within the range below, go to Step (4). If
not, adjust it using the trimmer.
Sensor unit type
Adjustable range
CDS-7
3.92-4.08mA
CHS-7
3.92-4.08mA
COS-7
17.32-17.48mA
*For COMM-less models, no need to adjust
with the trimmer, and the output is fixed at
4.0 mA or 17.4 mA with the LC-7 loop
checker.
a. Measure the analog output (current)
between the ―G‖ and ―H‖ terminals with
a multimeter, etc. If the output level is
within the range below, go to Step (4).
If not, adjust it using the trimmer.
Sensor unit type
Adjustable range
COS-7 (FS: 50%)
10.64-10.80mA
*For COMM-less models, no need to adjust
with the trimmer, and the output is fixed at
17.4 mA with the LC-7 loop checker.
Lift the cover flap open
To center position (normal operation mode)
Trimmer (adjustment screw)
Rotate the trimmer with a slotted screwdriver
to adjust the MNT2 output level.
Multimeter
G: +
H: -
Oxygen sensor
COS-7 (FS: 50vol%)
Toxic gas sensor
CDS-7
Combustible gas sensor:
CHS-7
Oxygen sensor
COS-7 (FS: 25vol%)
Analog output
20mA
Gas level
4mA
0mA
Full scale
0ppm
Normal air has an O
2
level of
21vol%. Adjust to 17.4mA.
Analog output
20mA
O
2
level
4mA
0mA
25vol%
0%
17.4mA
21vol%
Normal air has an O
2
level of
21vol%. Adjust to 10.7mA.
Analog output
20mA
O
2
level
4mA
0mA
50vol%
0%
10.7mA
21vol%
NOTE
