Detcon MicroSafe DM-534C Instruction Manual

DETCON, Inc.

www.detcon.com

July 20, 2018 • Document #2405 • Revision 1.5

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 [phone]

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 ....................................................................................................................... 14

10.0 SPARE PARTS LIST ............................................................................................................................ 15

11.0 WARRANTY ......................................................................................................................................... 16

12.0 SERVICE POLICY ............................................................................................................................... 16

13.0 SOFTWARE FLOWCHART ............................................................................................................... 16

Appendix C ....................................................................................................................................................... 17

Revision History ............................................................................................................................................. 17

DM-534C O2 Sensor Instruction Manual iii

DM-534C Oxygen Sensor Assembly

Shipping Address: 4055 technology Forest Blvd, Suite 100., The Woodlands Texas 77381

Phone: [phone] • F ax: 281.292.2860 • www.detcon.com • [e-mail]

Table of Figures

Figure 1 Construction of Galvanic Cell ............................................................................................................. 1

Figure 2 Microprocessor Control Circuit .......................................................................................................... 1

Figure 3 Base connector board .......................................................................................................................... 2

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 ........................................................................................................................... 15

Figure 12 Software Flowchart ........................................................................................................................... 16

List of Tables

Table 1 Interference Data .................................................................................................................................. 4

Table 2 Field wiring Table ................................................................................................................................ 6

Mailing Address: P.O. Box 8067, The W oodlands Texas 77387-8067

DM-534C O2 Sensor Instruction Manual iv

DM-534C Oxygen Sensor Assembly

1.0 DESCRIPTION

Detcon MicroSafe™ Model DM534C, oxygen defici ency sensors are non-intrusive “Smart” sensors desig ned
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, gal vanic metal air battery type cell, which is ho used 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 operatin g temperature range -4° to +122° Fahrenheit. T he sensor is warranted
for two years and has an expected service li f e of up to three years in ambient air at 20.9% oxygen.

Figure 1 Construction of Galvanic Cell

The control circuit is microprocesso r 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 ind icators,
magnetic programming switches, and a linear 4-20 mA DC output.

Figure 2 Microprocessor Control Circuit

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 1 of 17

DM-534C Oxygen Sensor Assembly

Customer

Wiring

Wiring to
O2 Sensor

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.

Figure 3 Base connector board

1.3 Explosion Proof Enclosure

The sensors are packaged in a cast me tal explosion proof enclosure. The enclosure is fitted with a threaded
cover that has a glass lens window. Mag netic program switches located behind the transmitter module face
plate are activated through the lens wind ow via a han dheld 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. 1.5 Page 2 of 17

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 oxyg en is adsorb ed into the electro ly te solutio n a current i s generated betw een
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 Dia gra m

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 operatin g outside these temperatures, performance specificati ons 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 gen erally
located 2-4 feet above grade.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 3 of 17

DM-534C Oxygen Sensor Assembly

Methane

100% = 0

Hydrocarbons

100% = 0

Hydrogen

100% = < 2%

Carbon Monoxide

20% = < 0.5%

3.2 Interference Data

Table 1 Interference Data

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 magnet ic program switches located under
the face plate. The two switches ar e referred to as “PGM 1” and “PGM 2”. The menu list c onsists of 3 items
which include submenus as indicated belo w. (Note: see the end of this manual for a comple te software flow
chart.)

1. Normal Operation
a) Current Status

2. Calibration Mode
a) Span

3. Program Menu
a) Program Status
b) Set Calibration Level

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DM-534C Oxygen Sensor Assembly

5.1 Normal Operation

In normal operation, the display tracks the cu rrent status of the sensor and gas concentration and app ears 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 (Vi ew 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/g as sensor devices is directl y relative to proper locati on and installation
practice.

6.1 Field Wiring Table (4-20 mA output)

Detcon MicroSafe™ O2 sensor assemblies req uire three conductor connection between power supplies and
host electronic controllers. Wiring designators are + (DC), - (DC), and mA (sensor signal). Maximu m single
conductor resistance between sensor and controller is 10 ohms. Maximum wire size fo r termination in the
sensor assembly terminal board is 14 AWG.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 5 of 17

DM-534C Oxygen Sensor Assembly

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 requir ed in installations where cable tray s or conduit runs
include high voltage lines or other sources of induced interference.

Note: In all installations, the sensor points down relative to grade (Figure 6). Improper
sensor orientation may result in false read ing and permanent sensor damage.

AWG

Meters

Feet

20

240

800

18

360

1200

16

600

2000

14

900

3000

Table 2 Field wiring Table

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 t arget gas is such that sensors fo r the detection of
heavier than air gases should be located within 2-4 feet of g rade as these heavy gases wil l 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 indu strial process include flanges, valves, and tubing
connections of the sealed type wh ere seals may either fail or we ar. Other leak sources are b est 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 ro oms, maintenance or warehouse buildings. A more general an d applicable
thought toward selecting sensor location is combining leak source and perimeter protection in the best possible
configuration.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 6 of 17

DM-534C Oxygen Sensor Assembly

Drain

Conduit

"T"

EYS Seal Fitting

PGM 1

PGM 2

MODEL DM-534C

HOUSTON, TEXAS

FLT CAL

MicroSafe O2 Gas Sensor

ALM ALM

TM

NOTE: For products utilizing the aluminum junction box option, the conduit seal shall be

enclosure. Crouse Hinds type EYS2, EYD2 or equivalent are suitable for this purpose.

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 assembli es are designed to meet
NEC and CSA requirements for Class I; Grou ps 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.

placed at the entry to the junction box (see Figure 6 as an example). For products utilizing
the stainless steel junction box option, the conduit seal shall be placed within 18” of the

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 (Figure 7).

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 7 of 17

DM-534C Oxygen Sensor Assembly

5.5"

6.1"

5.825"

7.92"

2"

0.5"

4.65"

Wall (or other

mounting surface

Splash Guard

O2 Sensor

Cal Port

1/4" Mounting holes

8-32 tapped
ground point

3/4" NPT Ports

Customer

Wiring

Wiring from
O2 Sensor

BlueBlue

White

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.

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 in stances where the gas sensor head must be mounted in a location
that is difficult to access. Such a lo cation creates problems for main tenance and calibration activities. De tcon
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 f i gure Figure 9 below for wiring diagram.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 8 of 17

Figure 8 Sensor Connector PCB

DM-534C Oxygen Sensor Assembly

Blue

White

Blue

White

Remote Transmitter
DM-534C-RT

Remote Sensor
DM-534C-RS

Note 1: If the display contrast needs adjustment, refer to section 8.7.

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 tempor ary upscale reading may occur as the sensor powers up. This upscale read ing 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.

Initial Operational Tests

After a warm up period has been allowed f or, the sensor should b e 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 housi ng. 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.

b) b) Remove the test gas and observe that the LCD display increases back to 20.9% ±2% of scale (0.5%

O2).

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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.

c) Initial operational tests are complete. Detcon O2 g as sensors are pre-calibrated prior to shipment and

will, in most cases, not require significant adjustment on start up. However, it is recommend ed 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 l ens cover to calibrate or change programming parameters.
Two switches labeled “PGM 1” and “PGM 2” allow for complete calibration and alarm le vel 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 Figure 10) is used to operate the switches. Switch action is defined as
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.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 10 of 17

DM-534C Oxygen Sensor Assembly

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.

NOTE 1: If th e circuitry is unable to adjust the span to the proper setting the sensor will

FAULT” (see section 3.7.3)..

8.1 Calibration Procedure - Span

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 co ncentrations may be used as long as they fall with in 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 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 PR OG 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.

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 a s: “CAL

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 11 of 17

DM-534C Oxygen Sensor Assembly

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 an d the calibration fault screen wh ich appears as: “CAL F AULT” If this o ccurs
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 o f span gas in the same concentration as the calibration gas level sett ing.
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 8.0 and make note of the setting found in listing number 2. The
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.

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.

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DM-534C Oxygen Sensor Assembly

h) Apply the calibratio n gas at a flow rate of 500 millili ters per minut e. As the sensor signal changes, the

display will change to “SPAN xx.x%”. The “xx.x” part of the rea ding indicates th e actual gas re ading
which will increase or decrease until the sen sor stabilizes. Wh en the sensor sign al 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 pro gram, the calibration gas level setting , as well as the estimated remainin g
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 2 5.0% 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 an d cause the display to altern ate between the sensor’ s current status
reading and the calibration fault screen which appears as: “CAL FAULT”

Fail-safe/Fault Supervision

Detcon MicroSafe™ sensors are programmed fo r 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 cau se the mA output to drop to zero (0) mA.

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 13 of 17

DM-534C Oxygen Sensor Assembly

Sensor Life

The sensor life feature is a reference bas ed on sign al output fro m the sensor cell . When a sen sor life of 2 5% or
less remains; the sensor cell should be repl aced within a reasonable maintenance schedule.

8.7 Display Contrast Adjust

Detcon MicroSafe™ sensors feature a 1 6-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 co mpensate for this charact eristic; however temp erature 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 th e enclosure cover an d use a jeweler’s screwd river to turn t he contrast
adjust screw located beneath the metallic face p late. The adjustment location is marked “CONTRAST”. See
Figure 2 for location.

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 l evel 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. 1.5 Page 14 of 17

DM-534C Oxygen Sensor Assembly

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

Sensor Head Wiring Connection

Sensor Head Wiring Connection

Sensor Head Wiring Connection

Sensor Head Wiring Connection

+24VDC Power IN

Common DC Power IN

4-20 mA Output

Customer Supplied

Wiring

6/32 X 3/8 Screw (2ea.)

#6 internal Star Washer (2ea.)

O2 Plug-In Sensor Assembly

P/N 370-399100-000

Transmitter Module DM-534
P/N 925-345400-025

Standard Connector Board
P/N 500-005065-007

O2 SS SENSOR HOUSING
P/N 399-200000-000

N7 Aluminum condulet, part of

Assembly # 897-850901-010

Splashguard with
Calibration Adapter
P/N:613-120000-700

Condensation Prevention Packet

P/N:960-202200-000

STANDARD CONNECTOR BOARD

P/N:500-005065-007

O2 Plug-In Sensor Assembly

P/N 027-02384-0

O'ring 1 1/4"ID X 1 7/16OD 0.103W

P/N 173

N7 Aluminum Lid with window, part

of Assembly # 897-850901-010

10.0 SPARE PARTS LIST

Figure 11 Spare parts diagram

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 15 of 17

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 y ear
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 y ear fixed fee service policy covering the
control circuit wherein any failed part s hall be repaired for a fee of $55. 00. The fixed fee service policy shall
affect any necessary factory repai r for the period following the two-year warranty period and sh all end five
years after expiration of the warranty . All warranties and service po licies are FOB the Detcon facili ty located
in The Woodlands, Texas.

13.0 SOFTWARE FLOWCHART

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 16 of 17

Figure 12 Software Flowchart

DM-534C Oxygen Sensor Assembly

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

Word format

BM

1.5

07/20/18

Updated Conduit Seal in Section 6.4

MM

Shipping Address: 4055 technology Forest Blvd, Suite 100., The Woodlands Texas 77381

Phone: [phone] • F ax: 281.292.2860 • www.detcon.com • [e-mail]

Appendix C

Revision History

Parts List (section 10.0). Added Revision history. Converted to

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

DM-534C O2 Sensor Instruction Manual Rev. 1.5 Page 17 of 17