DM-634C Oxygen Sensor Assembly
DM-634C O2 Sensor Instruction Manual Rev. .066
Page 6 of 25
*The alarm relay latch mode of the fault alarm. The menu item appears as:
“FLT NONLATCHING”
or
latching.
*The alarm relay energize state of the fault alarm. The menu item appears as
:
“FLT ENERGIZED”
or
de-energized.
*The calibration gas level setting. The menu item appears as:
“CalLevel @ xx.x%”
*Identification of the RS-485 ID number setting. The menu item appears as:
“485 ID SET @ ##”
*The estimated remaining sensor life. The menu item appears as:
“SENSOR LIFE 100%”
3.4.5
Alarm 1 Level Adjustment
The alarm 1 level is adjustable from 2.5% to 22.5%. The menu item appears as:
“SET ALM1 @ 19.5%”
3.4.6
Alarm 2 Level Adjustment
The alarm 2 level is adjustable from 2.5% to 22.5%. The menu item appears as:
“SET ALM2 @ 17.5%”
3.4.7
Calibration Level Adjustment
The calibration level is adjustable from 15.0% to 25.0% O2. The menu item appears as:
“CalLevel @ xx.x%”
3.5
Installation
Optimum performance of ambient air/gas sensor devices is directly relative to proper location and installation
practice.
3.5.1
Field Wiring Table (4-20 mA output)
Detcon MicroSafe™ O2 sensor assemblies require three conductor connection between power supplies and
host electronic controllers. Wiring designators are + (DC), – (DC), and mA (sensor signal). Maximum single
conductor resistance between sensor and controller is 10 ohms. Maximum wire size for termination in the
sensor assembly terminal board is 14 gauge
Table 2
Field wiring Table
Note 1
: This wiring table is based on stranded tinned copper wire and is designed to serve
as a reference only.
Note 2
: Shielded cable may be required in installations where cable trays or conduit runs
include high voltage lines or other sources of induced interference.
The RS-485 (if applicable) requires 24 gauge, two conductor, shielded, twisted pair cable between sensor and
host PC. Use Belden part number 9841. Two sets of terminals are located on the connector board to facilitate
serial loop wiring from sensor to sensor. Wiring designators are
A & B
(IN) and
A & B
(OUT).
AWG
Meters Feet
20
240
800
18
360
1200
16
600
2000
14
900
3000