Detcon MicroSafe™
Model DM-534C
Oxygen Deficiency Sensor (0-25% O2)
Operator’s Installation and Instruction Manual
4055 Technology Forest Blvd, Suite 100,
The Woodlands, Texas 77381
Ph.281.367.4100 / Fax 281.298.2868
February 21,2012 • Document #2405 • Revision 1.4
DETCON, Inc.
www.detcon.com
DM-534C Oxygen Sensor Assembly
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DM-534C O2 Sensor Instruction Manual ii
DM-534C Oxygen Sensor Assembly
Table of Contents
1.0
DESCRIPTION........................................................................................................................................ 1
1.1 Sensor Technology............................................................................................................................... 1
1.2 Base Connector Board..........................................................................................................................2
1.3 Explosion Proof Enclosure................................................................................................................... 2
2.0 PRINCIPLE OF OPERATION.............................................................................................................. 3
3.0 APPLICATION .......................................................................................................................................3
3.1 Sensor Placement/Mounting................................................................................................................. 3
3.2 Interference Data.................................................................................................................................. 4
4.0 SPECIFICATIONS ................................................................................................................................. 4
5.0 OPERATING SOFTWARE ................................................................................................................... 4
5.1 Normal Operation................................................................................................................................. 5
5.2 Calibration Mode.................................................................................................................................. 5
5.3 Program Mode...................................................................................................................................... 5
5.3.1 Program Status............................................................................................................................. 5
5.3.2 Calibration Level Adjustment....................................................................................................... 5
6.0 INSTALLATION..................................................................................................................................... 5
6.1 Field Wiring Table (4-20 mA output).................................................................................................. 5
6.2 Sensor Location.................................................................................................................................... 6
6.3 Local Electrical Codes.......................................................................................................................... 7
6.4 Accessibility......................................................................................................................................... 7
6.5 Installation Procedure...........................................................................................................................7
6.6 Remote Mounting Applications ........................................................................................................... 8
7.0 START UP................................................................................................................................................ 9
8.0 CALIBRATION..................................................................................................................................... 10
8.1 Calibration Procedure - Span ................................................................................................... .......... 11
8.2 Additional Notes................................................................................................................................. 12
8.3 Calibration Frequency........................................................................................................................ 12
8.4 Calibration Gas Level......................................................................................................................... 12
8.5 Status of Programming and Sensor Life............................................................................................. 13
8.6 Program Features................................................................................................................................ 13
8.7 Display Contrast Adjust ..................................................................................................................... 14
9.0 TROUBLE SHOOTING....................................................................................................................... 15
10.0 SPARE PARTS LIST............................................................................................................................ 16
11.0 WARRANTY......................................................................................................................................... 17
12.0 SERVICE POLICY............................................................................................................................... 17
Appendix C....................................................................................................................................................... 18
Revision History............................................................................................................................................. 18
Table of Figures
Figure 1 Construction of Galvanic Cell ............................................................................................................ 1
Figure 2 Microprocessor Control Circuit..........................................................................................................1
Figure 3 Base connector board..........................................................................................................................2
DM-534C O2 Sensor Instruction Manual iii
DM-534C Oxygen Sensor Assembly
Figure 4 Explosion proof enclosures................................................................................................................. 3
Figure 5 Functional Block Diagram..................................................................................................................3
Figure 6 Typical Installation .............................................................................................................................7
Figure 7 Typical Outline and Mounting Dimensions........................................................................................ 8
Figure 8 Sensor Connector PCB .......................................................................................................................8
Figure 9 Remote mounting application.............................................................................................................9
Figure 10 Magnetic Programming Tool............................................................................................................10
Figure 11 Spare parts diagram...........................................................................................................................16
List of Tables
Table 1 Interference Data..................................................................................................................................4
Table 2 Field wiring Table..............................................................................................................................5
Shipping Address: 4055 technology Forest Blvd, Suite 100., The Woodlands Texas 77381
Phone: 888.367.4286, 281.367.4100 • Fax: 281.292.286 0 •
DM-534C O2 Sensor Instruction Manual iv
Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067
www.detcon.com • sales@detcon.com
DM-534C Oxygen Sensor Assembly
1.0 DESCRIPTION
Detcon MicroSafe™ Model DM534C, oxygen deficiency sensors are non-intrusive “Smart” sensors designed
to detect and monitor O2 in air over the range of 0-25%. One of the primary features of the sensor is its
method of automatic calibration which guides the user through each step via instructions displayed on the
backlit LCD. The sensor output is a standard 4-20 mA signal. The microprocessor-supervised electronics are
packaged as a plug-in module that mates to a standard connector board. Both are housed in an explosion proof
condulet that includes a glass lens. A 16 character alpha-numeric indicator is used to display sensor readings as
well as the sensor’s menu driven features via a handheld programming magnet.
1.1 Sensor Technology
The sensor technology is of the two-electrode, galvanic metal air battery type cell, which is housed as a field
replaceable plug–in module. The cell is diffusion limited and functions as a direct current generator
proportional to the amount of oxygen adsorption. The sensors are temperature compensated and show good
accuracy and stability over the operating temperature range -4° to +122° Fahrenheit. The sensor is warranted
for two years and has an expected service life of up to three years in ambient air at 20.9% oxygen.
Figure 1 Construction of Galvanic Cell
The control circuit is microprocessor based and is packaged as a plug-in field replaceable module, facilitating
easy replacement and minimum down time. Circuit functions include a basic sensor preamplifier, onboard
power supplies, microprocessor, back lit alpha numeric display, calibration and fault status LED indicators,
magnetic programming switches, and a linear 4-20 mA DC output.
Figure 2 Microprocessor Control Circuit
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 1 of 18
DM-534C Oxygen Sensor Assembly
1.2 Base Connector Board
The base connector board is mounted in the explosion proof enclosure and includes: the mating connector for
the control circuit, reverse input and secondary transient suppression, input filter, and lugless terminals for
field wiring.
Wiring to
Customer
Wiring
O2 Sensor
Figure 3 Base connector board
1.3 Explosion Proof Enclosure
The sensors are packaged in a cast metal explosion proof enclosure. The enclosure is fitted with a threaded
cover that has a glass lens window. Magnetic program switches located behind the transmitter module face
plate are activated through the lens window via a handheld magnetic programming tool allowing non-intrusive
operator interface with the sensor. Calibration can be accomplished without removing the cover or
declassifying the area. Electrical classification is Class I; Groups B, C, D; Division 1.
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 2 of 18
DM-534C Oxygen Sensor Assembly
Figure 4 Explosion proof enclosures
2.0 PRINCIPLE OF OPERATION
Method of detection is by a controlled rate of diffusion. Air and gas diffuse through a sintered stainless steel
filter and a diffusion barrier. As oxygen is adsorbed into the electrolyte solution a current is generated between
the cathode and anode electrodes. This current output rises with increases in oxygen concentration and
reverses with lower concentrations. The quick response of the cell results in continuous monitoring of ambient
air conditions.
Figure 5 Functional Block Diagram
3.0 APPLICATION
Model DM-534C MicroSafe™ sensors are designed to detect and monitor oxygen deficiency in ambient air in
the range of 0-25%. Minimum sensitivity and scale resolution is 0.1%. Operating temperature range is -4° F. to
+122° F. While the sensor is capable of operating outside these temperatures, performance specifications are
verified within the limit.
3.1 Sensor Placement/Mounting
Sensor location should be reviewed by facility engineering and safety personnel. Area leak sources and
perimeter mounting are typically used to determine number and location of sensors. The sensors are generally
located 2-4 feet above grade.
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 3 of 18
DM-534C Oxygen Sensor Assembly
3.2 Interference Data
Table 1 Interference Data
Methane 100% = 0
Hydrocarbons 100% = 0
Hydrogen 100% = < 2%
Carbon Monoxide 20% = < 0.5%
4.0 SPECIFICATIONS
Method of Detection Air battery diffusion/adsorption
Electrical Classification Class I; Groups B, C, D; Div. 1.
Response Time (T90) T90 < 20 seconds
Clearing Time 90% < 20 seconds
Repeatability ± 2% FS
Range 0-25% O2
Operating Temperature -4° to +122° F
Accuracy ± 2% FS
Linearity ± 0.5% FS
Sensor Warranty 2 year conditional
Power Consumption 60 mA @ 24 VDC
Output Linear 4-20 mA DC
Input Voltage 11.5-28 VDC
5.0 OPERATING SOFTWARE
Operating software is menu listed with operator interface via the two magnetic program switches located under
the face plate. The two switches are referred to as “PGM 1” and “PGM 2”. The menu list consists of 3 items
which include submenus as indicated below. (Note: see the end of this manual for a complete software flow
chart.)
1. Normal Operation
a) Current Status
2. Calibration Mode
a) Span
3. Program Menu
a) Program Status
b) Set Calibration Level
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 4 of 18
DM-534C Oxygen Sensor Assembly
5.1 Normal Operation
In normal operation, the display tracks the current status of the sensor and gas concentration and appears as:
“20.9 % O2”" The mA current output corresponds to the monitoring level of 0-25% O2 = 4-20 mA.
5.2 Calibration Mode
Calibration mode allows for sensor zero and span adjustments. “2 - SPAN”
The default span adjustment is set at 20.9% which is the normal atmospheric concentration of O2. Span gas
concentrations other than 20.9 % may be used. Refer to section
8.1 for details “SPAN”
5.3 Program Mode
The program mode provides a program status menu (View Program Status) to check operational parameters
and allows for the selection of the calibration gas level setting.
5.3.1 Program Status
The program status scrolls through a menu that displays:
* The gas type, range of detection and software version number. The menu item appears as: “O2 0-25 Vxxx”
* The calibration gas level setting. The menu item appears as: “CalLevel @ xx.x%”
* The estimated remaining sensor life. The menu item appears as: “SENSOR LIFE 100%”
5.3.2 Calibration Level Adjustment
The Calibration level is adjustable from 15.0% to 25.0% O2. The menu item appears as: “CalLevel @ # #%”.
Factory default setting is 20.9%.
6.0 INSTALLATION
Optimum performance of ambient air/gas sensor devices is directly relative to proper location and installation
practice.
6.1 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 AWG.
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.
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 5 of 18
AWG Meters Feet
20 240 800
18 360 1200
16 600 2000
14 900 3000
DM-534C Oxygen Sensor Assembly
The RS485 (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).
6.2 Sensor Location
Selection of sensor location is critical to the overall safe performance of the product. Five factors play an
important role in selection of sensor locations:
(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
(5) Accessibility for routine maintenance
Density - Placement of sensors relative to the density of the target gas is such that sensors for the detection of
heavier than air gases should be located within 2-4 feet of grade as these heavy gases will tend to settle in low
lying areas. For gases lighter than air, sensor placement should be 4-8 feet above grade in open areas or in
pitched areas of enclosed spaces.
Leak Sources - Most probable leak sources within an industrial process include flanges, valves, and tubing
connections of the sealed type where seals may either fail or wear. Other leak sources ar e best determined by
facility engineers with experience in similar processes.
Ventilation - Normal ventilation or prevailing wind conditions can dictate efficient location of gas sensors in a
manner where the migration of gas clouds is quickly detected.
Personnel Exposure The undetected migration of gas clouds should not be allowed to approach concentrated
personnel areas such as control rooms, maintenance or warehouse buildings. A more general and applicable
thought toward selecting sensor location is combining leak source and perimeter protection in the best possible
configuration.
Note: In all installations, the sensor points down relative to grade (
sensor orientation may result in false reading and permanent sensor damage.
Figure 6). Improper
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 6 of 18
DM-534C Oxygen Sensor Assembly
Conduit
"T"
Drain
EYS Seal Fitting
PGM 1
MODEL DM-534CHOUSTON, TEXAS
TM
MicroSafe O2 Gas Sensor
ALM ALM
FLT CAL
PGM 2
Figure 6 Typical Installation
6.3 Local Electrical Codes
Sensor and transmitter assemblies should be installed in accordance with all local electrical codes. Use
appropriate conduit seals. Drains & breathers are recommended. The sensor assemblies are designed to meet
NEC and CSA requirements for Class I; Groups B, C, D; Div. 1 environments.
6.4 Accessibility
Consideration should be given to easy access by maintenance personnel as well as the consequences of close
proximity to contaminants that may foul the sensor prematurely.
Note: An appropriate conduit seal must be located within 18" of the sensor assembly.
Crouse Hinds type EYS2, EYD2 or equivalent are suitable for this purpose.
6.5 Installation Procedure
a) Remove the junction box cover and unplug the control circuit by grasping the two thumb screws and pulling
outward.
b) Securely mount the sensor junction box in accordance with recommended practice. See dimensional
drawing (
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 7 of 18
Figure 7).
DM-534C Oxygen Sensor Assembly
3/4" NPT Ports
6.1"
5.5"
5.825"
7.92"
1/4" Mounting holes
O2 Sensor
Splash Guard
2"
4.65"
8-32 tapped
ground point
Wall (or other
mounting surface
0.5"
Cal Port
Figure 7 Typical Outline and Mounting Dimensions
c) Observing correct polarity, terminate 3-conductor field wiring to the sensor base connector board in
accordance with the detail shown in
Figure 8.
d) Replace the plug-in transmitter circuit and replace the junction box cover.
BlueBlue
Wiring from
Customer
Wiring
O2 Sensor
White
Figure 8 Sensor Connector PCB
6.6 Remote Mounting Applications
Some sensor mounting applications require that the gas sensor head be remotely mounted away from the
sensor transmitter. This is usually true in instances where the gas sensor head must be mounted in a location
that is difficult to access. Such a location creates problems for maintenance and calibration activities. Detcon
provides the DM-534C sensor in a remote-mount configuration in which the sensor (Model DM-534C-RS) and
the transmitter (Model DM-534C-RT) are provided in their own condulet housing and are interfaced together
with a three conductor cable. Reference figure
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 8 of 18
Figure 9 below for wiring diagram.
DM-534C Oxygen Sensor Assembly
Remote Transmitter
DM-534C-RT
Blue
White
Remote Sensor
DM-534C-RS
Blue
White
Figure 9 Remote mounting application
7.0 START UP
Upon completion of all mechanical mounting and termination of all field wiring, apply system power and
observe the following normal conditions
a) “Fault” LED is off.
b) A temporary upscale reading may occur as the sensor powers up. This upscale reading will clear to
about 20.9% within a few minutes of turn-on, assuming there is no oxygen deficient condition in the
area of the sensor.
Note 1: If the display contrast needs adjustment, refer to section
Initial Operational Tests
After a warm up period has been allowed for, the sensor should be checked to verify reliable sensitivity to O2
gas.
Material Requirements
-Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
-Detcon PN 613-120000-000 Splash Guard with integral Cal Port -OR-
-Detcon PN 943-000006-132 Threaded Calibration Adapter
-Detcon PN 942-001123-000 Zero Air cal gas or use ambient air if no combustible gas is present.
a) Attach the calibration adapter to the threaded sensor housing. Apply the test gas at a controlled flow
rate of 500 ml/m. Observe that the LCD display decreases to a level of 3% or less.
8.7.
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DM-534C Oxygen Sensor Assembly
b) b) Remove the test gas and observe that the LCD display increases back to 20.9% ±2% of scale (0.5%
O2).
c) Initial operational tests are complete. Detcon O2 gas sensors are pre-calibrated prior to shipment and
will, in most cases, not require significant adjustment on start up. However, it is recommended that a
complete calibration test and adjustment be performed within 24 hours of installation. Refer to
calibration instructions in section
8.0.
8.0 CALIBRATION
Material Requirements
-Detcon PN 327-000000-000 MicroSafe™ Programming Magnet
-Detcon PN 613-120000-000 Splash Guard with integral Cal Port -OR-
-Detcon PN 943-000006-132 Threaded Calibration Adapter
-Detcon PN 942-001123-000 Zero Air cal gas or use ambient air if no combustible gas is present.
Programming Magnet Operating Instructions
Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the
transmitter face plate. DO NOT remove the glass lens cover to calibrate or change programming parameters.
Two switches labeled “PGM 1” and “PGM 2” allow for complete calibration and alarm level programming
without removing the enclosure cover, thereby eliminating the need for area declassification or the use of hot
permits.
Figure 10 Magnetic Programming Tool
A magnetic programming tool (see
momentary contact, 3-second hold, and 30-second hold. In momentary contact use, the programming magnet
is waved over a switch location. In 3 second hold, the programming magnet is held in place over a switch
location for 3 or more seconds. In 30 second hold, the programming magnet is held in place over a switch
location for 30 or more seconds. Three and thirty second hold is used to enter or exit calibration and program
menus while momentary contact is used to make adjustments. The location of “PGM 1” and “PGM 2” are
shown in figure 6.
Figure 10) is used to operate the switches. Switch action is defined as
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 10 of 18
DM-534C Oxygen Sensor Assembly
NOTE: If, after entering the calibration or program menus, there is no interaction with the
menu items for more than 30 seconds, the sensor will return to its normal operating
condition
.
8.1 Calibration Procedure - Span
NOTE 1: Before performing an ambient air O2 span calibration, be sure there is no
oxygen deficient condition present.
CAUTION: Verification of the correct calibration gas level setting and calibration span
gas concentration is required before “span” calibration. These two numbers must be
equal.
Calibration consists of entering the calibration function and following the menu-displayed instructions. The
display will ask for the application of span gas in a specific concentration. This concentration must be equal to
the calibration gas level setting. The factory default setting for span gas concentration is 20.9% O2 which is
the normal atmospheric concentration. Other concentrations may be used as long as they fall within 15.0% to
25.0% O2. However, any alternate span gas concentration value must be programmed via the calibration gas
level menu before proceeding with span calibration. Follow the instructions below for span calibration.
a) Verify the current calibration gas level setting as indicated by the programming status menu. To do
this, follow the instructions in section 3.8 and make note of the setting found in listing number 12.
The item appears as “CalGas @ xx.x %”.
b) If the calibration gas level setting is equ al to your calibration span gas concentration, proceed to item
“f”. If not, adjust the calibration gas level setting so that it is equal to your calibration span gas
concentration, as instructed in items “c” through “e”.
c) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30
seconds until the display reads “VIEW PROG STATUS”, and then withdraw the magnet. At this
point you can scroll through the programming menu by momentarily waving the programming
magnet over “PGM 1” or “PGM 2”. The menu options are: View Program Status, and Set Cal Level.
d) From the programming menu scroll to the calibration level listing. The menu item appears as: “SET
CAL LEVEL”. Enter the menu by holding the programming magnet stationary over “PGM 1” for 3
seconds until the display reads “CalGas @ ## %”, then withdraw the magnet. Use the programming
magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading
until the reading is equal to the desired calibration span gas concentration. Exit to the programming
menu by holding the programming magnet over “PGM1” for 3 seconds.
e) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or
automatically return to normal operation in 30 seconds.
f) From the calibration menu “2-SPAN” proceed into the span adjust function by holding the
programming magnet stationary over “PGM 2” for 3 seconds then withdraw the programming
magnet. If no change of Span level is desired, wait 30 seconds for menu to return to normal operation.
At this point the display will ask for the application of the target gas and concentration. The display
reads “APPLY xx.x %” The xx.x here will indicate the actual concentration requested.
g) Apply the calibration test gas at a flow rate of 500 milliliters per minute. If the calibration gas level is
set at 20.9% and ambient air is verified to be 20.9% (normal atmospheric concentration of O2) then
do nothing at this point. The sensor will auto calibrate to ambient air O2 concentration. After 3
minutes the sensor will auto span to the correct reading and the display will change to “REMOVE
GAS” then the display will return to the normal operating mode.
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 11 of 18
DM-534C Oxygen Sensor Assembly
NOTE 1: If the circuitry is unable to adjust the span to the proper setting the sensor will
enter into the calibration fault mode which will cause the display to alternate between the
sensor’s current status reading and the calibration fault screen which appears as: “CAL
FAULT” (see section 3.7.3)..
8.2 Additional Notes
1. Upon entering the calibration menu, the 4-20 mA signal drops to 2 mA and is held at this level until
you return to normal operation.
2. If during calibration the sensor circuitry is unable to attain the proper adjustment for span, the sensor
will enter into the calibration fault mode and cause the display to alternate between the sensor’s
current status reading and the calibration fault screen which appears as: “CAL FAULT” If this occurs
you may attempt to recalibrate by entering the calibration menu as described in section 3.7.1a. If the
sensor fails again, defer to technical trouble shooting.
8.3 Calibration Frequency
In most applications, monthly to quarterly calibration intervals will assure reliable detection. However,
industrial environments differ. Upon initial installation and commissioning, close frequency tests should be
performed, weekly to monthly. Test results should be recorded and reviewed to determine a suitable
calibration interval.
8.4 Calibration Gas Level
Calibration consists of entering the calibration function and following the menu-displayed instructions. The
default calibration gas level is 20.9% O2. The sensor however can be programmed to other calibration gas
levels as long as they fall within the range of 15.0% to 25.0%. If this is the case, during span calibration the
display will ask for the application of span gas in the same concentration as the calibration gas level setting.
Follow the instructions below for span calibration at settings other than 20.9%.
a) Verify the current calibration gas level setting as indicated by the programming status menu. To do
this, follow the instructions in section
item appears as “CalLevel @ xx.x%”
b) If the calibration gas level setting is equal to your calibration span gas concentration, proceed to item
“f”. If not, adjust the calibration gas level setting so that it is equal to your calibration span gas
concentration, as instructed in items “c” through “e”.
c) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30
seconds until the display reads “VIEW PROG STATUS”, and then withdraw the magnet. At this
point you can scroll through the programming menu by momentarily waving the programming magnet
over “PGM 1” or “PGM 2”. The menu options are: View Program Status, and Set Cal Level.
d) From the programming menu scroll to the calibration level listing. The menu item appears as: “ SET
CAL LEVEL”
e) Enter the menu by holding the programming magnet stationary over “PGM 1” for 3 seconds until the
display reads “CalLevel @ xx.x%”, and then withdraw the magnet. Use the programming magnet to
make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading until the
reading is equal to the desired calibration span gas concentration. Exit to the programming menu by
holding the programming magnet over “PGM1” for 3 seconds.
f) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or
automatically return to normal operation in 30 seconds.
8.0 and make note of the setting found in listing number 2. The
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 12 of 18
DM-534C Oxygen Sensor Assembly
g) From the calibration menu “2- SPAN” (section 8.1) proceed into the span adjust function by holding
the programming magnet stationary over “PGM 2” for 3 seconds until the display reads “APPLY
xx.x% O2” then withdraw the programming magnet. The x’s here indicating the gas concentration
requested.
h) Apply the calibration gas at a flow rate of 500 milliliters per minute. As the sensor signal changes, the
display will change to “SPAN xx.x%”. The “xx.x” part of the reading indicates the actual gas reading
which will increase or decrease until the sensor stabilizes. When the sensor signal is stable it will auto
span to the requested concentration and the display will change to “SPAN COMPLETE” for two
seconds and then “REMOVE GAS”. Remove the gas. As the signal level returns to ambient gas
conditions, the display will return to the normal operation menu, “20.9% O2”
8.5 Status of Programming and Sensor Life
The programming menu has a programming status listing that allows the operator to view the gas, range, and
software version number of the program, the calibration gas level setting, as well as the estimated remaining
sensor life.
The following procedure is used to view the programming status of the sensor:
a) First, enter the programming menu by holding the programming magnet stationary over “PGM 2” for
30 seconds until the display reads “VIEW PROG STATUS”, then withdraw the magnet. The menu
options are: View Program Status, and Set Cal Level.
b) Next, scroll to the “VIEW PROG STATUS” listing and then hold the programming magnet over
“PGM 1” for 3 seconds. The menu will then automatically scroll, at five second intervals, through the
following information before returning back to the “” listing.
1. The gas type, range of detection and software version number: The menu item appears as: “O2
0-25 VX.XXX” with the Xs indicating the current version of installed firmware.
2. The calibration gas level setting: The menu item appears as: “CalLevel @ xx.x%”.
3. The estimated remaining sensor life: The menu item appears as: “Sensor life 100%”.
c) Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or
automatically return to normal operation in 30 seconds.
8.6 Program Features
Detcon MicroSafe™ toxic gas sensors incorporate a comprehensive program to accommodate easy operator
interface and failsafe operation. Program features are detailed in this section. Each sensor is factory tested,
programmed, and calibrated prior to shipment.
Over Range
When the sensor detects gas greater than 25.0% O2, it will cause the display to flash “25% O2” on and off.
Sensor Fault
If either of the wires connecting the sensor cell to the connector board should fail and cause an open circuit,
the sensor will go into a fault condition. “SENSOR FAULT”
Calibration Fault
If during calibration the sensor circuitry is unable to attain the proper adjustment for zero or span, the sensor
will enter into the calibration fault mode and cause the display to alternate between the sensor’s current status
reading and the calibration fault screen which appears as: “CAL FAULT”
Fail-safe/Fault Supervision
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 13 of 18
DM-534C Oxygen Sensor Assembly
Detcon MicroSafe™ sensors are programmed for failsafe operation. Any of the following fault condition will
illuminate the fault LED, and cause the display to read its corresponding fault condition: “SENSOR FAULT”,
or “CAL FAULT”. A “Sensor Fault” will also cause the mA output to drop to zero (0) mA.
Sensor Life
The sensor life feature is a reference based on signal output from the sensor cell. When a sensor life of 25% or
less remains; the sensor cell should be replaced within a reasonable maintenance schedule.
8.7 Display Contrast Adjust
Detcon MicroSafe™ sensors feature a 16-character backlit liquid crystal display. Like most LCDs, character
contrast can be affected by viewing angle and temperature. Temperature compensation circuitry included in
the MicroSafe™ design will compensate for this characteristic; however temperature extremes may still cause
a shift in the contrast. Display contrast can be adjusted by the user if necessary. However, changing the
contrast requires that the sensor housing be opened, thus declassification of the area is required.
To adjust the display contrast, remove the enclosure cover and use a jeweler’s screwdriver to turn the contrast
adjust screw located beneath the metallic face plate. The adjustment location is marked “CONTRAST”. See
Figure 2 for location.
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 14 of 18
DM-534C Oxygen Sensor Assembly
9.0 TROUBLE SHOOTING
Memory or Error Reports
1. Reinitialize Sensor Unplug transmitter and replug transmitter then swipe magnet over PGM 1 in the
first 3 seconds. This will clear the processor and recover from error state. Remember to put in all
customer settings for range, alarm and cal gas level after re-initialization.
Non-readable Display
1. If display has blue background when hot, install sunshade to reduce temperature.
2. If poor contrast, adjust contrast pot accordingly.
Nothing Displayed – Transmitter not responding
1. Verify condulet has no accumulated water or abnormal corrosion.
2. Verify required DC power is applied to correct terminals.
3. Swap with a known good transmitter to determine if transmitter is faulty.
Bad 4-20 mA Output or RS485 Output
1. Check that wiring is connected to correct terminal outputs.
2. Swap with a known good transmitter to determine if transmitter is faulty.
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 15 of 18
DM-534C Oxygen Sensor Assembly
10.0 SPARE PARTS LIST
600-610000-000 Sensor splash guard
943-000006-132 Calibration Adapter for FP, IR, DM and O2 Sensors
500-005065-007 Connector board
327-000000-000 Programming Magnet
897-850902-010 Detcon Alum Condulet w/Window Cover
960-202200-000 Condensation prevention packet (replace annually).
370-399100-000 Plug in replacement O2 sensor cell
925-345400-025 Plug in control circuit
399-200000000 Stainless steel sensor housing assembly (does not include
plug in sensor
N7 Aluminum Lid with window, part
of Assembly # 897-850901-010
Customer Supplied
Wiring
4-20 mA Output
Common DC Power IN
+24VDC Power IN
O'ring 1 1/4"ID X 1 7/16OD 0.103W
P/N 173
Splashguard with
Calibration Adapter
P/N:613-120000-700
Standard Connector Board
P/N 500-005065-007
O2 Plug-In Sensor Assembly
O2 Plug-In Sensor Assembly
P/N 027-02384-0
P/N 370-399100-000
O2 SS SENSOR HOUSING
P/N 399-200000-000
Figure 11 Spare parts diagram
Sensor Head Wiring Connection
Sensor Head Wiring Connection
Sensor Head Wiring Connection
Sensor Head Wiring Connection
STANDARD CONNECTOR BOARD
Condensation Prevention Packet
P/N:500-005065-007
P/N:960-202200-000
Transmitter Module DM-534
P/N 925-345400-025
N7 Aluminum condulet, part of
Assembly # 897-850901-010
6/32 X 3/8 Screw (2ea.)
#6 internal Star Washer (2ea.)
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 16 of 18
DM-534C Oxygen Sensor Assembly
11.0 WARRANTY
Detcon, Inc., as manufacturer, warrants each new plug-in O2 sensor cell (PN 370-399100-000), for a two year
period under the conditions described as follows: The warranty period begins on the date of shipment to the
original purchaser and ends two years thereafter. The sensor cell is warranted to be free from defects in
material and workmanship. Should the sensor cell fail to perform in accordance with published specifications
within the warranty period, return the defective part to Detcon, Inc. for necessary repair or replacement.
12.0 SERVICE POLICY
Detcon, Inc., as manufacturer, warrants under intended normal use each new MicroSafe™ plug-in control
circuit to be free from defects in material and workmanship for a period of two years from the date of shipment
to the original purchaser. Detcon, Inc., further provides for a five year fixed fee service policy covering the
control circuit wherein any failed part shall be repaired for a fee of $55.00. The fixed fee service policy shall
affect any necessary factory repair for the period following the two-year warranty period and shall end five
years after expiration of the warranty. All warranties and service policies are FOB the Detcon facility located
in The Woodlands, Texas.
13.0 SOFTWARE FLOWCHART
Figure 12 Software Flowchart
DM-534C O2 Sensor Instruction Manual Rev. 1.4 Page 17 of 18
DM-534C Oxygen Sensor Assembly
Appendix C
Revision History
Revision Date Changes made Approvals
1.3 02/05/10 Last release BM
1.4 02/21/12 Removed section Calibration- Zero Span. Corrected Spare
Parts List (section 10.0). Added Revision history. Converted to
Word format
BM
Shipping Address: 4055 technology Forest Blvd, Suite 100., The Woodlands Texas 77381
Phone: 888.367.4286, 281.367.4100 • Fax: 281.292.286 0 •
DM-534C O2 Sensor Instruction Manual Rev.1.4 Page 18 of 18
Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067
www.detcon.com • sales@detcon.com
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