Detcon CX-DM User Manual

DETCON, Inc.

May 29. 2014 • Document # 4429 • Revision 1.3

Model CX-DM

CX-DM Toxic Gas Sensors

CX-DM O2 Deficiency Sensors

Operator’s Installation and Instruction Manual

Covers all Model CX-DM Sensors

4055 Technology Forest Blvd, Suite 100

The Woodlands, Texas 77381

Phone: 713.559.9200 • Fax: 281.292.2860

www.detcon.com

Model CX-DM

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Model CX-DM ii

Model CX-DM

Table of Figures

Figure 1 Construction of Electrochemical Toxic Sensor ...................................................................................... 1

Figure 2 Construction of Galvanic Cell ................................................................................................................ 1

Figure 3 Sensor Assembly Breakaway ................................................................................................................. 2

Figure 4 Functional Block Diagram ..................................................................................................................... 2

Figure 5 Plug-in Sensor ........................................................................................................................................ 3

Figure 6 Approval Label ...................................................................................................................................... 3

Figure 7 CX-DM Sensor with Mini-Condulet ...................................................................................................... 6

Figure 8 Sensor Wire Connections ....................................................................................................................... 8

Figure 9 Terminal Interconnect ............................................................................................................................ 9

Figure 10 Magnetic Programming Tool ............................................................................................................. 11

Figure 11 Magnetic Programming Switches ...................................................................................................... 12

Figure 12 Software flow chart ............................................................................................................................ 13

Figure 13 Modbus™ Frame Format ................................................................................................................... 21

Figure 14 Sensor Cell and ITM Mating ............................................................................................................. 24

List of Tables

Table 1 Protection vs. Wire Gauge....................................................................................................................... 7

Table 2 CX-DM Register Map ........................................................................................................................... 22

Table 3 Sensor Specific Data ............................................................................................................................. 32

Table 4 Interfering Gases ................................................................................................................................... 34

Table 5 Cross Interference Table ....................................................................................................................... 35

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

Model CX-DM iv

Model CX-DM

1. Introduction

1.1 Description

Detconꞌs CX-DM sensor for toxic gas and O monitor a wide range of toxic gases in air. Detection ranges for toxic gases are 0-1ppm up to 0-10,000ppm (typical ranges of detection are 0-10ppm, 0-25ppm, 0-50ppm and 0-100ppm). Ranges for O 1% up to 0-25% by volume. The basic sensor assembly consists of an electrochemical sensor mounted in an intrinsically safe stainless steel housing and includes a Splash Guard Cal Adapter.

Electrochemical Sensor Technology

The toxic gas sensors are based on electrochemical cells. Each cell consists of three electrodes embedded in an electrolyte solution and housed beneath a diffusion membrane. Sensitivity to target gases is achieved by varying composition of any combination of the sensor components. The cells are diffusion limited by way of small capillary barriers resulting in a long service life of three or more years. The electrochemical cell is packaged as a field replaceable plug -in sensor.

deficiency are non-intrusive sensors designed to detect and

2

deficiency are 0-

2

Figure 1 Construction of Electrochemical Toxic Sensor

Principle of Ope r at io n

The O

deficiency sensor technology is a two electrode galvanic metal air battery type cell housed as a field

2

replaceable intelligent plug-in sensor. 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 of -20°C to 50°C (-4°F to +122°F). The sensor is warranted for two years with an expected service life of up to 2.5 years in ambient air at 20.9% oxygen.

Figure 2 Construction of Galvanic Cell

CX-DM Instruction Manual Rev. 1.3 Page 1 of 40

Model CX-DM

CX-DM Bottom

Housing Assembly

Plug-in Replaceable Sensor

Intelligent Transmitter Module (ITM) Micro-processor controlled circuit encapsulated in an Explosion proof housing.

Magnetic

Programming Switches

Splash Guard

3

4

" NPT Locking

Nut

All metal components are constructed from electro polished 316 Stainless Steel to maximize corrosion resistance in harsh environments.

mA Output Power In

Power

Intrinsically Safe Barrier

Modbus Output

1.2 Modular Design

The CX-DM sensor assembly is completely modular and is composed of four parts (Figure 3).

1. CX-DM Intelligent Transmitter Modu le (I TM)

2. Plug-in Electrochemical Sensor (varies by gas type and range)

3. CX Series Bottom Housing

4. Splash Guard

Figure 3 Sensor Assembly Breakaway

NOTE

CX-DM Intelligent Transmitter Module

The transmitter module is microprocessor-based and attached to the explosion proof junction box. Circuit functions include an intr insi cal ly s af e b arri er , on-board power supply, microprocessor, magnetic programming switches, and a linear 4-20mA DC output. Magnetic program switches (located on either side of the ITM) are activated by a hand-held magnetic programming tool, allowing non-intrusive operator interface with the transmitter module. Electrical classifications are Class I, Div 1, Groups B, C, and D.

Plug-In

Sensor

Micro-

Processor

I/O

Circuit

Protection

supplies

Figure 4 Functional Bloc k Diagram

Field Replaceable Sensor

Detconꞌs electrochemical gas sensors are field proven, plug-in sensors with over-sized gold-plated connections that eliminate corrosion problems. The sensor can be easily accessed and replaced in the field by releasi ng the locking screw and unthreading the splashguard adapter assembly. Detconꞌs toxic sensors have a long shelf life and supported by an industry-leading warranty.

CX-DM Instruction Manual Rev. 1.3 Page 2 of 40

Model CX-DM

Figure 5 Plug-in Sens or

2. Installation

2.1 Hazardous Location s Installation Guidelines for Safe Use

1. Install the sensor only in areas with classifications matching the approval label. Follow all warnings

listed on the label.

Figure 6 Approval Label

2. Do not remove the junction box cover while in the classified are unless it is conformed the there is no

explosive gas levels in the area.

3. A good ground connection should be verified between the sensor’s metal enclosure and the junction

box. If a good ground connection is not made, the sensor can be grounded to the junction box using the sensor’s external ground lug. Verify a good ground connection between the junction box and earth ground.

4. Proper precautions should be taken during installing and maintenance to avoid the build-up of static

charge on the plastic components of the sensor (Splash Guard) Wipe with damp cloth on plastic components to avoid static discharge.

5. Do not substitute components. Substitution of components may impair the intrinsic safety rating.

6. Do not operate the sensor outside of the stated operating temperature limits.

7. Do not operate the sensor outside the stated operating limits for voltage supply.

8. These sensors meet ATEX standards EN60079-0:2012. EN60079-1:2007 and EN60079-11:2012.

9. These sensors have a maximum safe location voltage of Um=30V.

10. The CX-DM apparatus is not capable of withstanding the 500V insulation test required by clause

6.3.12 of IEC/EN 60079-11:2007 (and by clause 6.8.1 of CSA Std. 142); thus, the enclosure must be grounded.

CX-DM Instruction Manual Rev. 1.3 Page 3 of 40

Model CX-DM

In all installations, the gas sensor should point straight down. Improper sensor orientation may result in false readings and permanent sensor damage.

11. The CXT-DM may be used as an oxygen deficiency sensor; the CXT-DM must not be used for

detecting oxygen concentrations expected to be greater than 21%

12. The CXT-DM must only use gas sensor cell model 371-xxxx00-yyy. No other gas sensor shall be

used.

2.2 Sensor Placement

Sensor location is critical to the overall safe performance of the product. Confirm that the following five factors are verified during sensor placement.

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. Maintenance access

Density

Sensor placement should be relative to the density of the target gas. For the detection of heavier than air gases, sensors should be located within 4 feet of grade since heavy gases typically settle in low lying areas. For gases lighter than air, sensor placement should be 4 to 8 feet above grade in open areas or in pitched areas of enclosed spaces.

Leak Sources

The most leak sources in an industrial process are flanges, valves, and tubing connections where seals may either fail or wear. Other leak sources are 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 movement 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. Selecting sensor location should combine leak so urce and perimeter protection in the best possible configuration.

Maintenance Access

Consideration should be given to providing easy access for maintenance personnel and the consequences of close proximity to contaminants that may cause the sensor to wear prematurely.

NOTE

CX-DM Instruction Manual Rev. 1.3 Page 4 of 40

Model CX-DM

If wall mounting without a mounting plate, make sure to use at least 1/2" spacers underneath

the wall and to allow access to the sensor assem bly .

Metal-on-metal contact must be maintained to provide a solid electrical ground path. Only

be externally

grounded using a ground strap.

Additional Placement Considerations

The sensor should not be positioned where it might be sprayed or coated with surface contaminating substances. Painting sensor assemblies is prohibited.

Although the sensor is designed to be RFI resistant, it should not be mounted in close proximity to highpowered radio transmitters or sim ilar RFI generati ng equipment.

When possible mount in an area void of high wind, accumulating dust, rain, splashing from hose spray, direct steam releases, and continuous vibration. If the sensor cannot be mounted away from potentially damaging conditions then use the Detconꞌs Harsh Location Dust Guard accessory.

Do not mount in locations where temperatures will exceed the operating temperature limits of the sensor. Use a sunshade to maintain correct operating temperature if mounted in direct sun light.

2.3 Sensor Cont aminants and Interferen ce

Electrochemical toxic gas may be adversely affected by exposure to other airborne gases. Depending on the cross-sensitivity relationship, there may be a false high or false low reading. The most common gases that may cause interference are referenced in Section 8.3 (Table 4 and Table 5).

Cross-Interference Data T ab le

Gases typically found in industrial environments that may cause interference with Detconꞌs toxic gas sensors are listed in Section 8.3, Table 5. To effectively reference the table; locate the chosen gas, scan across the row for possible interference gases, and then determine the magnitude of cross-interference that may occur.

2.4 Sensor Mounting

Vertically position the CX-DM so the sensor points straight down. The explosion-proof enclosure or junction box is typically mounted on a wall or pole. Detcon provides a selection of standard junction boxes in aluminum and stainless steel.

NOTE

When mounting on a pole, secure the junction box to a suitable mounting plate and attach the mounting plate to the pole using U-Bolts. (Pole-Mounting brackets for Detcon junction boxes are available separately .)

the aluminum junction boxes 1/4" mounting holes to move the sensor assembly away from

use Teflon Tape or other pipe thread material on the 3/4" threads if the sensor is mounted in a severe or harsh environment. If Teflon Tape is used the Sensor must

CX-DM Instruction Manual Rev. 1.3 Page 5 of 40

Model CX-DM

6-32 tapped ground point

3.45

3

4

NPT Port

4.2

Ø0.4 X 0.475" mounting holes

Splash Guard Adapter

Splash Guard

ITM Assembly

Typ.

3.47

A conduit seal is required to be located within 18" of the J-Box and sensor assembly. Crouse Hinds type EYS2, EYD2 or equivalent are suitable for this purpose.

NOTE

Water damage from water leaking into the enclosure is not covered by the Detcon warranty.

Unused ports should be blocked with suitable 3/4" male NPT plug. Detcon supplies one 3/4"

appropriate male plug of like construction material.

2.5 Electrica l Installation

Figure 7 CX-DM Sensor with Mini-Condulet

The sensor assembly wiring should be installed in accordance with local electrical codes. Proper electrical installation of the gas sensor is critical for conformance to electrical codes and to avoid damage due to water leakage.

If a conduit run exists, a drain should be incorporated. The drain allows condensation inside the conduit run to drain safely away from the sensor assembly. Electrical seals act as a secondary seal to prevent water from entering the wiring enclosure. However, electrical seals are not designed to provide an absolute watertight seal, especially when used in the vertical orientation. The electrical seal fitting is required to meet the National Electrical Code per NEC Article 500-3d (or Canadian Electrical Code Handbook Part 1 Section 18-154). Requirements for locations of electrical seals are covered under NEC Article 501-5.

NOTE

NPT male plug with each J-box enclosure. If connections are other than 3/4" NPT, use an

CX-DM Instruction Manual Rev. 1.3 Page 6 of 40

Model CX-DM

CAUTION

Over-Current

Protection

22

0.723mm

3A

20

0.812mm

5A

18

1.024mm

7A

16

1.291mm

10A

14

1.628mm

20A

NOTE 1: Wiring table is based on stranded tinned copper wire and is designed to serve as a reference only.

NOTE 2: Shielded cable is required for installations where cable trays or conduit runs include high voltage lines or other possible sources of induced interference. Separate conduit runs are highly recommended in these cases.

NOTE 3: The supply of power should be from an isolated source with over-current pr ot ect i on as stipulated in ta b le.

Do not apply system power to the sensor until all wiring is properly terminated (Section 2.7).

2.6 Field Wiring

Detcon Model CX-IR se nsor assemblies require three conductor connections between power supplies and host electronic controller’s 4-20mA output. Wiring designations are + (DC), – (DC), and mA (sensor signal. Maximum wire ohmic resistance between sensor and 24VDC source is defined below. Maximum wire size for termination in the De tc o n J-Box accessory is 14 gauge.

Max Resistance drop on red and black wire is 10 ohms. This considers wire diameter, wire length and maximum operation temperature.

Max loop load resistance between green and black wire is 500 ohms. Minimum loop load resistance between green and black wire is 100 ohms. This is considers wire diameter, wire length, max operating temperature and selected termination resistor.

AWG Wire Dia.

Table 1 Protection vs. Wire Gauge

2.6.1 Terminal Connections 3-Wire 4-20mA

CAUTION: Do not apply System power to the sensor until all wiring is properly terminated. Refer to Section 2.5 Initial Start Up

CX-DM Instruction Manual Rev. 1.3 Page 7 of 40

Model CX-DM

mA

(+)

(-)

Wiring to

Sensor Assembly

Red

Green

Black

Explosion

Proof

Junction Box

(+)

mA

(-)

Wiring to

Controller

Red

Green

Black

Detcon Inc.

Rev. 1

440-005208-000

MODULE

PROTECTION

TRANSIENT

Figure 8 Sensor Wire Connecti ons

a) Remove the junction box cover. Identify the terminal blocks for customer wire connections. b) Observing correct polarity, terminate the 3-conductor 4-20mA field wiring (+, -, mA) to the sensor

assembly wiring in accordance with the detail shown in Figure 8.

c) Replace the junction box cover.

2.6.2 Terminal Connections 4-20mA and RS-485

1. Remove the junction box cover.

2. Connect the incoming 24V to the terminal labeled "+" and 24V return to the terminal labeled "–". Connect

the mA output to the “mA” terminal and the Modbus signals (if used) to the “A” and “B” terminals. Note: the “Y” terminal is not used.

3. Replace the junction box cover after Initial Start Up (Section 2.7).

CX-DM Instruction Manual Rev. 1.3 Page 8 of 40

Model CX-DM

B A

mA VV+

Black

Red

Green

Blue

White

Blue

Green

Red

Black

To Sensor

Wiring

Ferrite

Bead

A 6-32 or 8-32 threaded exterior ground point is provided on most junction boxes for an

strap must be used to ensure that the sensor is electrically grounded.

Figure 9 Terminal Interconnect

NOTE

external ground. If the sensor assembly is not mechanically grounded, an external ground

2.7 Initial Start Up

Toxic Gas Sensors

Upon completion of all mechanical mounting, apply power to the sensor. Observe the following normal conditions:

1. Upon power up, the sensor will scroll "CX-DM V##.##" and will then display the current reading for

about 5 seconds. A temporary upscale reading may occur as the sensor stabilizes. This upscale reading will decrease to "0" ppm within 1 to 2 minutes of power-up, assuming there is no gas in the area of the sensor. Sensors cells that use a bias voltage require a longer time to stabilize. This can vary between 1 and 24 hours depending on the sensor type and range. Biased sensors include NH VOC gases (ethylene oxide, ethylene, methanol, formaldehyde….etc.).

2. After the initial power up, the sensor display will turn off . T hereafter the display will come on once

every 10 seconds, display the current reading for 2 seconds, and then return to a blank display.

, NO, HCl, and

3

Initial Operational Tests

After a warm up period of 1 hour (or when zero has stabilized), verify that the sensor has sensitivity to the target gas.

CX-DM Instruction Manual Rev. 1.3 Page 9 of 40

Model CX-DM

Calibration gas generators using perm tubes or electrochemical sources may be used in place of span gas cylinders.

The wind guard must be used during calibration with the integral cal port to ensure proper calibration.

Material Requirements

• Splash Guard with integral Cal Port and with Wind Guard (Detcon PN 613-120000-700) -or-

• Threaded Calibration Adapter (Detcon PN 943-000006-132) - or -

• Teflon Calibration Adapter for highly reactive gases (Detcon PN 943-01747-T05)

• Detcon Span Gas; 50% of range target gas in balance N

500cc/min (500cc/min is preferred)

NOTE

13. Attach the calibration adapter to the splashguard adapter assembly or connect tubing to integral cal port. It is recommended that the wind guard is installed over the splash guard during calibration.

14. Apply the test gas at a controlled flow rate of 200 - 500cc/min (500cc/min is the recommended flow). Observe that the ITM display increases to a level near that of the applied calibration gas value.

NOTE

15. Remove the test gas and ensure that the display decreases to "0".

16. If a calibration adapter was used during these tests, remove them from the unit, and re-install the

Splash Guard. If used, remove the wind guard.

Initial operational tests are complete. CX-DM toxic gas sensors are factory calibrated prior to shipment, and should not require significant adjustment upon start up. However, it is recommended that a complete calibration test and adjustment be performed 16 to 24 hours after power-up. Refer to zero and span calibration instructions in Section 3.3.

or Air at fixed flow rate between 200-

2

2.7.1 O2 Deficiency Sensors

1. When first powered up, the CX-DM display should read close to 20.9%.

2. The reading should stabilize within 1 to 2 minutes of power-up (assuming a normal ambient O

concentration).

Initial Operational Tests

2

After a warm-up period of 5 minutes, verify that the sensor responded to the O

deficiency.

2

Material Requirements

• 700 Series Splash Guard with integral Cal Port and with Wind Guard (Detcon PN 613-120000-700 )

-or-

• Threaded Calibration Adapter (Detcon PN 943-000006-132)

• Detcon Zero Gas: 100% N2 at fixed flow rate of 200-500cc/min

1. Attach the calibration adapter to the threaded sensor housing or connect tubing to the integral cal port.

Apply the test gas at a controlled flow rate of 200-500cc/min (500cc/min is the recommended flow). Observe that the ITM display decreases to a level near z ero .

CX-DM Instruction Manual Rev. 1.3 Page 10 of 40

Model CX-DM

The wind guard must be used during calibration with the integral cal port to ensure proper calibration.

NOTE

2. Remove test gas and calibration adapter. The ITM display should return to a reading of 20.9%.

Initial operational tests are complete. CX-DM O

deficiency sensors are factory calibrated prior to shipment,

2

and should not require significant adjustment on start up. However, it is recommended that a complete calibration test and adjustment be performed 16 to 24 hours after power-up. Refer to zero and span calibration instructions in Section 3.3.

3. Operation

The operator interface of the CX Series gas sensors is accomplished with two internal magnetic switches located to either side of the LED display (Figure 10). The two switches, labeled PGM1 and PGM2, allow for complete calibration and configuration, eliminating the need for area de-classification or the use of hot permits.

Figure 10 Magnetic Programming Tool

The magnetic programming tool (Figure 10) is used to operate the magnetic switches. Switch action is defined as momentary contact (a swipe), a 3-second hold, and a 10-second hold. (Hold times are defined as the time from the point when the arrow prompt appears. Swiping the magnet does not display the arrow prompt.) For momentary contact use, the programming magnet is briefly held over a switch location, or swiped. For 3second hold, the programming magnet is held in place over the switch location for three seconds. For 10second hold, the programming magnet is held in place over the switch location for 10 seconds. T he 3 and 10 second holds are generally used to enter calibration/program menus and save new data. The momentary contact is generally used to move between menu items and to modify set-point values. Arrows (◄ and ►) are used on the LED display to indicate when the magnetic switches are activated. The location of PGM1 and PGM2 are shown in Figure 11.

CX-DM Instruction Manual Rev. 1.3 Page 11 of 40

Model CX-DM

While in Program Mode, if there is no magnetic switch interaction after 4 consecutive menu

active.

Program Switch #1

LED Display

Program Switch #2

PGM2

SPAN

PGM1

ZERO

MODEL

CX-DM

detcon inc.

H 2 S Sensor

Figure 11 Magnetic Programmi ng S witc he s

scrolls, the sensor will automatically revert to normal operating condition. While changing

NOTE

values inside menu items, if ther e is no magnet activity after 3 to 4 seconds the sensor will revert to the menu scroll. If the sensor is in Bump Test mode, the display will remain

3.1 Operator Interface

The operating interface is menu-driven via the two magnetic program switches located under the target marks of the sensor housing. The two switches are referred to as PGM1 and PGM2. The menu list consists of three menu items that include sub-menus:

Normal Operation

Concentration reading is displayed once every 10 seconds.

Calibration Mode

AutoZero AutoSpan

Program Mode

View Sensor Status

CX-DM ##.## Range ### Autospan Level ## Modbus ID ## Tempcomp Level ## Last Cal ## Days Sensor Life ###% Temperature ##C

Set Detection Range

CX-DM Instruction Manual Rev. 1.3 Page 12 of 40

Model CX-DM

dec

LEGEND: PGM1 - Program Switch Location #1

PGM2 - Program Switch Location #2 (S) - Momentary Swipe

(M) - Momentary hold of Magnet during text scroll until the ">" appears, then release (3) - 3 second hold from ">" prompt (10) - 10 second hold from ">" prompt Auto Time-out - 5 seconds

inc - Increase dec - Decrease #, ##, ### - numeric values

AutoZero

PGM1 (3)

PGM2 (10)

PGM2 (3)

inc

Auto Time-Out

View Sensor Status

PGM1/2 (3)

PGM1/2 (M)

PGM2 (S)

PGM1/2 (3)

PGM1 (S)

##

AutoTime-out

PGM1/2 (3)

PGM1/2 (M)

Set Detection Range

AutoSpan

Normal Operation

PGM1 (3)

Auto Time-Out

inc

PGM2 (S)

PGM1/2 (3)

PGM1 (S)

##

PGM1/2 (3)

PGM1/2 (M)

Set Autospan Level

dec

inc

PGM1/2 (3)

PGM1 (S)

PGM2 (S)

##

dec

PGM1/2 (3)

PGM1/2 (M)

Set Modbus ID

Status is CX-DM V

Range ###

Autospan Level ##

Modbus ID ##

Tempcomp Level ##

Last Cal # Days

Sensor Life ###

Temperature ##

PGM1/2 (M)

Defaults Restored

PGM1/2 (3)

Restore Defaults

Auto Time-Out

dec

inc

PGM2 (S)

PGM1/2 (3)

PGM1 (S)

##

AutoTime-out

PGM1/2 (3)

PGM1/2 (M)

Bump Test

Set Autospan Level Set Modbus ID Bump Test Restore Defaults

Software Flowchart

Figure 12 Software flow chart

3.2 Normal Operation

In normal operation, the Intelligent Transmitter Module (ITM) dis play will be blank and will displ ay the gas reading once every 10 seconds for about 2 seconds (normally appear as "0"). At any time, swiping a magnet across either PGM1 or PGM2 will cause the ITM to display the range and gas type (i.e. "ppm H2S"). If th e sensor is actively experiencing any diagnostic faults, a swipe of the magnet will cause the display to scroll the fault condition. Refer to Section 5 Service and Maintenance for more information on fault conditions.

3.3 Calibration Mode

Zero and span calibration should be performed on a routine basis (quarterly minimum is advised) to ensure reliable performance. If a sensor has been exposed to any de-sensitizing gases, or to very high over -range

CX-DM Instruction Manual Rev. 1.3 Page 13 of 40

Model CX-DM

Upon entering calibration mode, the Modbus™ status register bit 14 is set to signify the

operation.

The zero gas source may be zero air or N2 for toxic sensors, but must be pure N2 (99.99%) for O2 deficiency sensors.

The Calibration Wind Guard must be used when the Splashguard Adapter with integral Cal

to use the Calibration Wind Guard may result in an inaccurate

AutoZero calibration.

The "◄" prompt will show that the magnetic switch is activated during the 3 second hold period.

NOTE

Upon entering calibration mode, the Modbus™ status register bit 14 is set to signify the

combustible gas levels, re-calibration should be considered. Unless otherwise specified, span adjustment is recommended at 50% of the full scale range.

To enter calibration mode hold the magnet over PGM1 for 3 seconds. If the sensor is experiencing a fault condition the "►" prompt will not appear until the fault(s) have been displayed. When the ITM enters calibration mode the display will scroll Pgm1=Zero Pgm2=Span twice before returning to normal mode (about 5 seconds).

NOTE

sensor is in-calibration mode. This bit will remain set until the program returns to normal

3.3.1 AutoZero

The AutoZero function will zero the sensor. AutoZero should be performed periodically or as required. AutoZero should be considered after periods of over-range target gas exposure. Local ambient air can be used to zero calibrate a toxic gas sensor as long as it can be confirmed that it contains no target or interference gasses. If this cannot be confirmed then a zero air or N zero calibration of the O

deficiency sensors.

2

Material Requirements:

• MicroSafe™ Programming Magnet (Detcon PN 327-000000-000)

• Splash Guard with integral Cal Port (Detcon P/N 613-120000-700) and Calibration Wind Guard

(Detcon PN 613-120000-700 ) -or-

• Threaded Calibration Adapter (Detcon PN 943-000006-132)

• Zero Air cal gas (or use ambient air if no target gas is present) (Detcon PN 942-001123-000 )

• Nitrogen 99.99% (Detcon P/N 942-640023-100)

NOTE

cylinder should be used. Pure N2 must be used for

2

NOTE

Port is used. Failure

1. Toxic sensors, if the ambient air is known to contain no target gas content, can be used for zero

calibration. If a zero gas cal cylinder is going to be used, attach the calibration adapter and set flow rate of 200-500cc/min (500cc/min is the recommended flow rate) and let sensor purge for 1 to 2 minutes before executing the AutoZero. For O

deficiency sensors, apply N2 at a set flow rate of

2

500cc/min for 3 to 5 minutes before executing AutoZero.

2. From Normal Operation, enter Calibration Mode by holding the programming magnet over PGM1 for

3 seconds. The "◄" prompt will show that the magnetic switch is activated during the 3 second hold period. The display will then scroll Pgm1=Zero Pgm2=Span. Hold the programming magnet over PGM1 for 3 seconds once the "◄" prompt appears to execute AutoZero (or allow to timeout in 5 seconds if AutoZero is not desired).

NOTE

CX-DM Instruction Manual Rev. 1.3 Page 14 of 40

Model CX-DM

sensor is in-calibration mode. This bit will remain set until the program returns to normal operation.

Before performing AutoSpan Calibration, verify that the AutoSpan level matches the span calibration gas concentration as described in Section 3.4.3.

NOTE

Contact Detcon for ordering information on span gas cylinders.

A target gas concentration of 50% of range is strongly recommended. This should be

c/min being the recommended flow rate. Other concentrations can be used if they fall within allowable levels of 5% to 100% of range.

The Calibration Wind Guard must be used when the Splashguard Adapter with integral Cal

the Calibration Wind Guard may result in an inaccurate

AutoSpan calibration.

Ambient air should be used to calibrate O2 deficiency sensors as long as the oxygen concentration is confirmed to be 20.9%

It is generally not advised to use other gasses to cross-calibrate for span. Cross-calibration by use of other gasses should be confirmed by Detcon.

CAUTION

Verification that the calibration gas level setting matches the calibration span gas

numbers must be equal.

3. The ITM will display the following sequence of text messages as it proceeds through the AutoZero

sequence:

Zero Cal. . . Setting Zero. . . Zero Saved ( each will scroll twice)

4. Remove the zero gas and calibration adapter, if applicable.

3.3.2 AutoSpan

The AutoSpan function is used to span calibrate the sensor. AutoSpan should be performed periodically or as required. AutoSpan should be considered after periods of over-range target gas exposure. Unl ess otherwise specified, span adjustment is recommended at 50% of range. This function is called "AUTO SPAN".

NOTE

Material Requirements:

• MicroSafe™ Programming Magnet (Detcon PN 327-000000-000)

• Splash Guard with integral Cal Port (Detcon P/N 613-120000-700) and Calibration Wind Guard

(Detcon PN 613-120000-700 ) -or-

• Threaded Calibration Adapter (Detcon PN 943-000006-132)

• Detcon Span Gas (See Detcon for Ordering Information). Recommended span gas is 50% of range

with target gas. Other suitable span gas sources containing the target gas in air or N

balance are

2

acceptable.

NOTE

supplied at a controlled flow rate of 200 to 500cc/min, with 500c

NOTE

Port is used. Failure to use

NOTE

concentration is required before executing "AUTOSPAN" calibration . Thes e two

CX-DM Instruction Manual Rev. 1.3 Page 15 of 40

Model CX-DM

The "◄" prompt will show that the magnetic switch is activated during the 3 second hold period.

Ambient air should be used to calibrate O2 deficiency sensors as long as the oxygen concentration is confirmed to be 20.9%. There is no need to apply a flow of gas.

When calibrating O2 deficiency sensors, there is no requirement to clear to <5% of range. The sensor will return to normal operation immediately after span adjustment.

If the sensor fails the minimum signal change criteria, a Range Fault will be declared and the Range Fault bit will be set on the Modbus™ output.

If the sensor fails the clearing time criteria, a Clearing Fault will be declared and the Clearing fault bit will be set on the Modbus™ output.

AutoSpan consists of entering Calibration Mode and following the displayed instructions. The display will ask for the application of span gas in a specific concentration. The applied gas concentration must be equal to the calibration gas level setting. The factory default setting and recommendation for span gas concentration is 50% of range. If a span gas containing the recommended concentration is not available, other concentrations may be used as long as they fall between 5% and 100% of range. However, any alternate span gas concentration value must be programmed via the Set AutoSpan Level menu before proceeding with AutoSpan calibration.

1. Verify that the AutoSpan Level is equal to the Calibration Span Gas Concentration. (View Sensor

Status in Section 3.4.1.) If the AutoSpan Level is not equal to the Calibration span gas concentration, adjust the AutoSpan level as instructed in Section 3.4.3.

2. From normal operation, enter Calibration Mode by holding the programming magnet over PGM1 for

3 seconds.

NOTE

3. The display wil l scroll ‘PGM1=Zero PGM2=Span’. Hold the programming magnet over PGM2

for 3 seconds to execute AutoSpan (or allow to timeout in 5 seconds if AutoSpan is not i nt e nd ed). The ITM will scroll ‘Apply XX ppm Gas’.

4. Apply the span calibration test gas for toxic gas sensors at a flow rate of 200-500cc/min (500cc/min is

the recommended flow rate). As the sensor signal begins to increase the display will switch to flashing XX reading as the ITM shows the sensorꞌs "as found" response to the span gas presented. If it fails to meet the minimum in-range signal change criteria within 2 minutes, the display will report Range Fault twice and the ITM will return to normal operation, aborting the AutoSpan sequence. The ITM will continue to report a "Range Fault" for 1 minute.

NOTE

5. Assuming acceptable sensor signal change, after 1 minute the reading will auto-adjust to the

programmed AutoSpan level. The ITM then reports the following messages: ‘Remove Gas’.

6. Remove the span gas source and calibration adapter. The ITM will report a live reading as it clears

toward "0". When the reading clears below 10% of range, the ITM will display ‘Span Complete’ and will revert to normal operation. If the sensor fails to clear to less than 10% in less than 5 minutes, a ‘Clearing Fault’ will be reported twice and the ITM will return to normal operation, aborting the AutoSpan sequence. The ITM will continue to report a Clearing Fault until a successful calibration is completed.

NOTE

7. AutoSpan calibration is complete.

NOTE

CX-DM Instruction Manual Rev. 1.3 Page 16 of 40

Model CX-DM

The arrow prompts (◄ and ►) will show that the magnetic switch is activated during the 3 second hold period.

PGM1 moves the menu items from right to left and PGM2 moves the menu items from left to right.

3.4 Program M ode

Program Mode provides menus to check and set operational and configuration parameters of the sensor. Program Mode provides for adjustment of the AutoSpan Level, configuration parameters, detection range adjustment, and AutoSpan Level. Program mode includes the diagnostic function bump test and restores defaults.

The program mode menu items appear in the order presented below:

View Sensor Status Set Detection Range Set Autospan Level Set Modbus ID Bump Test Restore Defaults

Navigating Program Mode

From normal operation, enter program mode by holding the magnet over PGM2 for 3 seconds. The "►" prompt will verify that the magnetic switch is activated. If the sensor is experiencing a fault condition the "►" prompt will not appear until the fault(s) have been displayed.

NOTE

The ITM will enter program mode and the first menu item View Sensor Status will be displayed. Hold the magnet over PGM1 or PGM2 while the current menu text is scrolling to advance to the next menu item.

At the conclusion of the text scroll the arrow prompt ("►" for PGM2 or "◄" for PGM1) will appear, immediately remove the magnet. The ITM will advance to the next menu item. Repeat this process until the desired menu item is displayed.

NOTE

To enter a menu item, hold the magnet over PGM1 or PGM2 while the menu item is scrolling. At the conclusion of the text scroll the "►"prompt ("►" for PGM2 or "◄" for PGM1) will appear, continue to hold the magnet over PGM1 or PGM2 for an additional 3 to 4 seconds to enter the selected menu item. If there is no magnet activity while the menu item text is scrolling (typically 4 repeated text scrolls), the ITM will automatically revert to Normal Operation.

3.4.1 View Sensor Status

View Sensor Status displays all current configuration and operational parameters including: sensor type,

software version number, gas type, detection range, AutoSpan level, days since last AutoSpan, estimated remaining sensor life, raw sensor current, mA output, input voltage and sensor ambient temperature.

• CX-DM ##.##

• Range ###

• Autospan Level ##

• Modbus ID ##

• Tempcomp Level ##

• Last Cal ## Days

• Sensor Life ###%

CX-DM Instruction Manual Rev. 1.3 Page 17 of 40

Model CX-DM

NOTE

The sensor range should not be changed in the field unless directed to do so by Detcon.

• Temperature ##C

From the View Sensor Status text scroll, hold the magnet over PGM1 or PGM2 until the "►" prompt appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll Status Is). The display will scroll the complete list of sensor status parameters sequentially:

When the status list sequence is complete, the ITM will revert to the View Sensor Status text scroll. The user can either:

• review the list again by executing another 3 to 4 second hold, or

• move to another menu item by swiping over PGM1 or PGM2, or

• return t o nor mal operation by the automatic timeout of about 15 seconds (the display will scroll View

Sensor Status four times before returning to normal operation).

3.4.2 Set Detection Range

The CX -DM sensor is calibrated at the factory for the range specified by the customer. Field adjustments to the predetermined range should only be made under direct supervision of Detcon.

3.4.3 Set AutoSpan Level

Set AutoSpan Level is used to set the span gas concentration level used to calibrate the sensor. This leve l is

adjustable from 1% to approximately 75% or 95% depending on the full-scale range. The current setting can be viewed in View Program Status.

The menu will display Se t AutoSpan Level. From the Set AutoSpan Level text scroll, hold the magnet over PGM1 or PGM2 until the "►" prompt

appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll Set Level). The display will switch to XX (where XX is the current AutoSpan level).

Swipe the magnet momentarily over PGM2 to increase or PGM1 to decrease the AutoSpan Level until the correct level is displayed. When the correct level is achieved, hold the magn et over PGM2 for 3 to 4 seconds to accept the new value. The display will scroll Level Saved, and revert to Set AutoSpan Level text scroll.

Move to another menu item by executing a momentary hold, or return to normal operation by the automatic timeout of about 15 seconds (the display will scroll Set AutoSpan Level four times before returning to normal operation).

3.4.4 Bump Test

Bump test checks the response of the sensor with the indication of response limited to the display only. The bump test mode allows the performance of the sensor to be checked without firing the alarms of any attached control systems. The results of the bump test will not affect the reading register on the Modbus™ output.

The menu item appears as: Bump Test.

From the Bump Test scroll, hold the magnet over PGM1 or PGM2 until the "►" prompt appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll Bump Test Started).

CX-DM Instruction Manual Rev. 1.3 Page 18 of 40

Model CX-DM

Restoring factory defaults should only be used when absolutely necessary. All previously

second magnet hold on PGM2 is required to execute this function.

NOTE

The following must be performed in order before the sensor can be placed in operation.

Apply span gas to the sensor in accordance with Section 0. The sensor will respond to the gas testing the sensor response while the current Modbus gas reading (Modbus register 0002) remains unchanged. Remove the gas before the bump test time expires (2 minutes).

The display will return to normal operation and alternate between showing the live gas reading, and showing "Bump" for 2 mi nutes, or the execution of a momentary hold over PGM1 or PGM2 , when the displ ay will scroll Bump Test Ended.

3.4.5 Restore Defaults

Restore Factory Defaults clears the c urrent user configuration and calibration data from memory and reverts

back to factory default values. Returning to a factory default is common when settings have been configured improperly and a known reference point needs to be re-established to correct the problem.

This menu item appears as: Restore Defaults.

NOTE

existing configuration inputs will have to be re-entered if this function is executed. A full 10

From the Restore Defa ults scroll, hold the programming magnet over PGM2 until the "►" prompt appears and continue to hold for 3 to 4 seconds. The display will scroll Defaults Restored, and revert to Restore Defaults text scroll.

Move to another menu item by executing a momentary hold or, return to normal operation by the automatic timeout of about 15 seconds (the display will scroll Restore Defaults 4 times and return to normal operation).

Following the execution of Restore Defaults, the CX-DM will revert to its factory default settings. The default settings are as follows:

• AutoSpan Level = 50% of range. AutoSpan level must be set appropriately by the operator (Section

3.4.3).

• Range: Defaults to range of intelligent plug-in sensor, must be set to the appropriate level by the

operator (Section 3.4.2).

• Modbus ID = 01. The Modbus ID must be set appropriately by the user (Section 3.4.6).

• AutoZero: AutoZero Settings are lost and the user must perform new AutoZero (Section 3.3.1).

• AutoSpan: AutoSpan Settings are lost and user must perform new AutoSpan (Section 3.3.2).

3.4.6 Set Modbus ID

Detconꞌs CX sensor can be polled serially via Modbus™ RTU. Refer to Section 4 for details on using the Modbus™ output feature. The Modbus™ is adjustable from 01 to 256 in hexadecimal format (01-FF) hex. Each sensor must have a unique Modbus address to operate correctly on the network. The current serial ID can be viewed in View Sensor Status.

The menu item appears as: Set Serial ID. From the Set Modbus ID scroll, hold the programming magnet over PGM1 or PGM2 until the "►" prompt

appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll Set ID). The display will then switch to XX (where XX is the current ID address).

CX-DM Instruction Manual Rev. 1.3 Page 19 of 40

Model CX-DM

Swipe the magnet over PGM2 to increase or PGM1 to decrease the hexadecimal number until the desired ID is displayed. Hold the magnet over PGM2 for 3 to 4 seconds to accept the new value. The display will scroll ID Saved, and revert to Set Modbus ID text scroll.

Move to another menu item by executing a momentary hold or, return to normal operation by automatic timeout of about 15 seconds (the display will scroll Set Serial ID 5 times and return to normal operation).

3.5 Fault Diagnostic/Failsafe Feature

If the ITM should incur a fault, the Global Fault bit will be set on the Modbus™ output. This can occur if the ITM detects a problem with the sensor, detects that there is no sensor connected, if the ITM has an internal fault, or other fault condition. The Global Fault bit will be set on the Modbus™ output until the problem is resolved. The display will show the fault when a magnetic programming tool is swiped across either PGM1 or PGM2. The error codes are defined in the Troubleshooting Guide (Section 6).

CX-DM Instruction Manual Rev. 1.3 Page 20 of 40

Model CX-DM

Address Field

Function Code

Data

CRC

A write to a Read Only register is allowed and returns a response, but it does not change the value of the register.

4. Modbus™ Communications

Model CX-DM sensors feature Modbus™ compatible communications protocol and are addressable via the operator interface. Communication is two wire, half duplex 485, 9600 baud, 8 data bits, 1 stop bi t, and no parity. If a multi-point system is being utilized, each sensor should be set for a different address. Typical address settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11…etc.

Sensor RS-485 ID numbers are factory default to 01 and can be changed in the field using the operator interface (Section 3.5.5).

4.1 General Modbu s™ De scr ip ti on

The Modbus™ communication uses the RTU transmission mode per the Modbus™ specification. The ba sic frame format for Modbus™ consists of a Modbus™ address, function code, data and CRC.

Figure 13 Modbus™ Frame Format

The Modbus ID Field is the unique Modbus™ address of each device on the network. The Function Code is the function to be performed. The Data contains read or write data and is formatted according to the function being performed. The CRC (Cyclic Redundancy Code) is used to detect errors in the frame. Frames with errors are invalid and ignored.

Modbus™ transactions consist of a request by the controller and response from the device being addressed so there are two frames transferred for every transaction. Every request is evaluated by the CX-DM to determine if it is addressed, and if it falls within the register address range. If these two conditions are true, the CX-DM will then verify a valid Function Code. Function Codes supported by the CX-DM are as follows:

• Function Code 03 (03h) – Read Holding Registers

• Function Code 06 (06h) – Write Single Register

• Function Code 16 (10h) – Write Multiple Registers

If an invalid function code is performed, the CX-DM will ignore the request.

4.2 Modbus™ Register Map & Description

When the CX-DM is assigned a Modbus™ address, the following registers become available to the controller for access. All CX-DM sensors implement this r egister set . Some registers are Read Only (R) and others are Read/Write (R/W) as shown by the R/W column. This equates to specific function codes where Read is function code 03 and Write is function code 06 or 16.

NOTE

Table 2 is the register map for the CX-DM sensor and gives a brief description each register or register set. This information is only meant as a reference. For a more detailed description of the Register Map please contact Detcon.

CX-DM Instruction Manual Rev. 1.3 Page 21 of 40

Model CX-DM

40000

CX-DM-100 Device Type

R

= 42

40001

Range

R/W

Detectable Range

ppm or %(O2)

40002

Reading

R

Current Gas Reading

ppm or %(O2)

40003

Calibration Level

R/W

Auto Span Level

ppm or %(O2)

40004

Life

R

Sensor Life

%

40005

Sensor Faults

R

See Section 4.2.1

40006

Sensor Model

R

DM (set to 1)

40007

Days since Calibration

R days

40008

Reserved

R

40009

Reserved

R

40010

Sensor Temperature

R ºC

# of decimal places in reading,

values

40012

Temperature Compensation

R/W

See Section 4.2.2

40013

Reserved

R

40014

Sensor Counts

R/W

40015

Calibration Enable/Status

R/W

40016

Gas Type/Units String

R

ASCII Text (set at factory)

40017

Gas Type/Units String

R

ASCII Text (set at factory)

40018

Gas Type/Units String

R

ASCII Text (set at factory)

40019

Gas Type/Units String

R

ASCII Text (set at factory)

40020

Gas Type/Units String

R

ASCII Text (set at factory)

40021

Gas Type/Units String

R

ASCII Text (set at factory)

NOTE

Bits read as 0 are FALSE, bits read as 1 are TRUE.

Table 2 CX-DM Register Map

Register Name R/W Meaning Units

40011 Decimal Places R/W

range, and AutoSpan level

4.2.1 Sensor Faults – Register 40005

The sensor fault status register consists of High and Low Status Bits. These bits are set/reset as faults occur or are cleared. Each Bit has a particular meaning and displayed as follows:

Register # High Byte Low Byte

0005 Status Bits Status Bits

Status Bits High Byte: Bit 15 – Reserved Bit 14 – Calibration Mode Bit 13 – Reserved Bit 12 – Zero Fault Bit 11 – Range Fault Bit 10 – Reserved Bit 9 – Clearing Fault Bit 8 – Reserved

Status Bits Low Byte: Bit 7 – Sensor Fault Bit 6 – Processor Fault Bit 5 – Memory Fault

CX-DM Instruction Manual Rev. 1.3 Page 22 of 40

Model CX-DM Bit 4 – Reserved

Bit 3 – Reserved Bit 2 – Temperature Fault Bit 1 – Auto Span Fault Bit 0 – Global Fault

4.2.2 Temperature Compensation – Register 40012

The CX -DM implements temperature compensation for certain gas types. The possible values for this register are as follows:

0 = No temperature compensation 1 = CO - temperature compensation 2 = H

- temperature compensa tion

2

3 = NH 4 = ETO - temperature compensation 5 = ETHYLENE - temperature compensation 6 = VINYL CHLORIDE - temperature compensation 7 = METHANOL - temperature compensation 8 = ETHANOL - temperature compensation 9 = ACRYLONITRILE - temperature compensation 10 = ACETALDEHYDE - temperature compensation 11 = CL

- temperature compensation

3

- temperature compensation

2

CX-DM Instruction Manual Rev. 1.3 Page 23 of 40

Model CX-DM

It is not necessary to remove power while changing the plug-in toxic gas sensor in order to maintain area classification. The sensor is intr insically safe.

NOTE

Only replace the plug-in sensor with an authorized CX-DM family of gas sensors.

ITM

(Bottom View)

Display Window

Plug in Sensor

(Bottom view)

Locking

Setscrew

Locking

Setscrew

5. Service and Maintenance

Calibration Frequency

In most applications, monthly to quarterly span calibration intervals will assure reliable detection. With industrial environments varyi ng, after 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.

Visual Inspection

The Sensor should be inspected annually for the following:

• Inspect the sensor for signs of corrosion, pitting, and water damage.

• Remove the Splash Guard and inspected it for blockage, broken, cracked, or missing pieces.

• For H2S Sensor assemblies, inspect CX-DM Series Splashguard Adapter Assembly with integral filter (P/N

602-003803-200) for blockage of filter material.

• Inspect inside of the Junction Box for signs of water accumulation, signs of corrosion.

• Check wiring to ensure there are no loose or pinched wires and all connections are clean and tight.

Condensation Prevention Packet

A moisture condensation packet should be installed in every explosion proof junction box. The packet will prevent the internal volume of the J-Box from condensing and accumulating moisture due to day-night humidity changes. This packet provides a critical function and should be replaced annually.

5.1 Replacement of Plug-in Sensor

NOTE

Figure 14 Sensor Cell and ITM Mating

CX-DM Instruction Manual Rev. 1.3 Page 24 of 40

Model CX-DM

NOTE

One turn of the setscrew will suffice - Do not remove setscrew completely.

It is necessary to remove power to the junction box while changing the ITM in order to maintain area classification .

NOTE

One turn of the setscrew will suffice - Do not remove setscrew completely.

It is necessary to remove power to the Junction box while changing the ITM in order to maintain area classification .

1. Use a 1/16" Allen wrench to release the locking setscrew that locks the ITM and splashguard adapter

assembly together.

2. Remove the splashguard. Unthread and remove the splashguard adapter assembly from the ITM.

3. Gently pull the plug-in sensor out of the ITM. Verify that the gas type and range of the new sensor cell

is correct. Orient the new plug-in sensor so that it matches with the female connector pins. When properly aligned, press the sensor in firmly to make the proper connection.

4. Thread t he splashguard adapter assembly onto the ITM to a snug fit and tighten the locking setscrew

using the

1

/16" Allen wrench. Reinstall the splashgu a rd.

5. Check and perform zero calibration and span calibration in accordance with Section 3.3.

5.2 Replacement of ITM – Aluminum J-Box

1. Remove the power source to the sensor assembly. Disconnect all sensor wire connections at the

junction box terminal board, taking note of the wire connections.

NOTE

2. Use a wrench at the top section of the ITM and unthread the ITM until it can be removed.

3. Use a

1

/8" Allen wrench to release the locking cap head screw that locks the ITM and splashguard

adapter assembly together.

4. Unthread and remove the splashguard adapter assembly and splash guard from the ITM. These will be

re-used with the new ITM.

5. Gently remove the plug-in toxic gas sensor from the old ITM and install the sensor i n the new ITM.

Orient the plug-in sensor so it matches the female connector pins on the new ITM and press the sensor in firmly to make proper connection.

6. Thread the splashguard adapter assembly onto the new ITM until snug, tighten the locking cap head

screw and reinstall splash guard.

7. Feed the sensor assembly wires through the

3

/4" f emale NPT port and thread the assembly into the Jbox until tight and the ITM faces toward the front access point. Use the locking nut to secure the ITM in this position. Re-connect the sensor assembly wires to the terminal board inside the junction box.

8. Check and/or perform Zero Calibration and Span Calibration in accordance with Section 3.3.

5.3 Replacement of ITM – Stainless Steel Mini Condulet

NOTE

CX-DM Instruction Manual Rev. 1.3 Page 25 of 40

Model CX-DM

NOTE

One turn of the setscrew will suffice - Do not remove setscrew completely.

1. Disconnect the sensor wire connections from the terminal board, taking note of the wire connections.

2. Use a wrench at the top section of the ITM and unthread the ITM until it can be removed.

3. Use a

1

/8" Allen wrench to release the locking cap head screw that locks the ITM and splashguard

adapter assembly together.

4. Unthread and remove the splashguard adapter assembly and splash guard from the ITM. These will be

re-used with the new ITM.

5. Gently remove the plug-in toxic gas sensor from the old ITM and install it in the new ITM. Orient the

plug-in sensor so it matches the female connector pins on the new ITM and press the sensor in firmly to make proper connection.

6. Thread the splashguard adapter assembly onto the new ITM until snug, tighten the locking cap head

screw and reinstall splash guard.

7. Feed the sensor assembly wires through the

3

/4" female NPT port and thread the assembly into the Jbox until tight and the ITM faces toward the front access point. Use the locking nut to secure the ITM in this position.

8. Re-connect the sensor assembly wires to the terminal board inside the junction box.

9. Check and/or perform Zero Calibration and Span Calibration in accordance with Section 3.3.

CX-DM Instruction Manual Rev. 1.3 Page 26 of 40

Model CX-DM

6. Troubleshooting Guide

If the ITM detects any functional errors the ITM will display the fault. If the sensor is experiencing a fault condition a momentary swipe of the magnet will cause the ITM to scroll the fault condition(s) across the display before the "◄" or "►" prompt will appear.

The Display Error Codes are:

Auto Span Fault Temperature Fault Memory Fault Processor Fault Clearing Fault Range Fault Sensor Fault Zero Fault Sensor Fault 2

Some faults are self-explanatory, and if these faults occur and cannot be cleared the ITM should be replaced first to see if the fault will clear. Other faults may need further investigation. Some of the sensor problems, associated error codes, and resolution s are lis ted belo w.

6.1 Under-Range problems

Probable Cause: Sensor Baseline drifted lower, Interference gases,

• Perform Zero Calibration. Use Zero Air or N

• Allow more time for zero stabilization if this is a biased sensor type.

• If using Splashguard with Integral Cal Port, must use Calibration Wind Guard or air movement can

compromise span gas delivery.

• Execute successful Span Calibration. (Section 3.3.2 AutoSpan)

• Replace plug-in toxic sensor if error continues.

6.2 Stability problems

Probable Causes: Failed Sensor, empty or close to empty Cal Gas Cylinder, problems with cal gas

and delivery

• Check validity of span gas using pull tube or other means (check MFG date on cal gas cylinder).

• Use proper cal gas regulators and tubing for highly corrosive gases

• If using Splashguard with Integral Cal Port, must use Calibration Wind Guard or air movement can

compromise span gas delivery.

• Check for obstructions affecting cal gas hitting sensor face (including being wet, blocked, or

corroded). H2S sensors assemblies use CX-DM Series Splashguard Adapter Assembly with integral filter. Clean or replace if necessary.

• Replace the plug-in toxic sensor.

source. (Section3.3.1 AutoZero)

2

6.3 Clearing problem

Probable Causes: Failed Sensor, Cal Gas not removed at appropriate time, problems with cal gas and

delivery, Background of Target Gas.

• The sensor must recover to < 5% of range in < 5 min after Span calibration is complete

• Use bottled air (zero air or N

• Check validity of span gas using pull tube or other means (check MFG date on cal gas cylinder).

• Use proper cal gas regulators and tubing for highly corrosive gases

CX-DM Instruction Manual Rev. 1.3 Page 27 of 40

) if there is a known continuous background level.

2

Model CX-DM

• Check for obstructions affecting cal gas hitting sensor face (including being wet, blocked, or

corroded). H2S sensors assemblies use CX_DM Series Splashguard Adapter Assembly with integral filter. Clean or replace if necessary.

• Replace the plug-in toxic sensor.

6.4 Poor Calibration Repeatability

Probable Causes: Failed Sensor, use of wrong Cal Gas or problems w/ cal gas and delivery,

Interference Gases

• Check validity of span gas with regulator and sample tubing in place using pull tube or other

means (check MFG date on cal gas cylinder).

• Use proper cal gas regulators and tubing for highly corrosive gases (HF, HCI, Cl2, NH3, HBR, F2,

etc.)

• Check for obstructions affecting cal gas hitting sensor face (including being wet, blocked, or

corroded). H2S sensors assemblies use CX-DM Series Splashguard Adapter Assembly with integral filter. Clean or replace if necessary.

• Replace the plug-in toxic sensor.

6.5 Unstable Output/ sudden spiking

Possible Causes: Unstable power supply, inadequate grounding, or inadequate RFI protection.

• Verify Power source is stable.

• Verify field wiring is properly shielded and grounded.

• Contact Detcon to optimize shielding and grounding.

6.6 Nuisance Alarms

• Check condulet for accumulated water and abnormal corrosion on terminal board.

• If nuisance alarms are happening at night, suspect condensation in condulet.

• Add or replace Detcon’s Condensation Prevention Packet P/N 960-202200-000.

• Investigate the presence of other target gases that are causing cross-interference signals.

• Determine if cause is RFI induced.

6.7 Intelligent Transmitter Module (ITM) not respondin g

• Verify condulet has no accumulated water or abnormal corrosion.

• Verify required batteries are installed and have enough charge to power the sensor.

• Swap with a known-good ITM to determine if ITM is faulty.

Contact the Detcon Service Department for further troubleshooting assistance at 713-559-9200.

CX-DM Instruction Manual Rev. 1.3 Page 28 of 40

Model CX-DM

All additional parts must be supplied by Detcon. Use of parts from a third party will void warranty and safety approvals.

NOTE

CX-DM should only be repaired by Detcon personnel or a Detcon trained representative.

7. Customer Support and Service Policy

Detcon Headquarters Shipping Address: 4055 Technology Forest Blvd, The Woodlands, Texas 77381 Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067 Phone: 713.559.9200 Fax: 281.298.2868

• www.detcon.com

• service@detcon.com

• sales@detcon.com

All Technical Service and Repair activities should be handled by the Detcon Service Department via phone, fax or email (contact information given above). RMA numbers should be obtained from the Detcon Service Department prior to equipment being returned. For on-line technical service, have the model number, part number, and serial number of product(s) in question available.

All Sales activities (including spare parts purchase) should be handled by the Detcon Sales Department via phone, fax or email (contact information given above).

NOTE

7.1 Warranty Notice

Detcon Inc. warrants the Model CX-DM gas sensor to be free from defects in workmanship of material under normal use and service for one year from the date of shipment on the transmitter electronics. See Warranty details in the CX-DM Sensor Warranty (Section 7.2).

Detcon Inc. will repair or replace without charge any such equipment found to be defective during the warranty period. Full determination of the nature of, and responsibility for, defective or damaged equipment will be made by Detcon Inc. personnel.

Defective or damaged equipment must be shipped to the Detcon Inc. factory or representative from which the original shipment was made. In all cases, this warranty is limited to the cost of the equipment supplied by Detcon Inc. The customer will assume all liability for the misuse of this equipment by its employees or other contracted personnel.

All warranties are contingent upon the proper use in the application for which the p roduct was i ntended and does not cover products which have been modified or repaired without Detcon Inc. approval, or which have been subjected to neglect, accident, improper installation or application, or on which the original identification marks have been removed or altered.

Except for the express warranty stated above, Detcon Inc. disclaims all warranties with regard to the products sold. Including all implied warranties of merchantability and fitness and the express warranties stated herein are in lieu of all obligations or liabilities on the part of Detcon Inc. for damages including, but not limited to, consequential damages arising out of, or in connection with, the performance of the product.

CX-DM Instruction Manual Rev. 1.3 Page 29 of 40

Model CX-DM

7.2 CX-DM Sensor Warranty

Plug-in Sensor Warranty

Detcon Inc. warrants, under normal intended use, each new plug-in sensor per the period specified in the Warranty column of Table 3 Sensor Specific Data (Section 8.2) and under the conditions described as follows: The warranty period begins on the date of shipment to the original purchaser. The sensor element is warranted to be free of defects in material and workmanship. Should any sensor fail to perform in accordance with published specifications within the warranty period, return the defective part to Detcon, Inc., 4055 Technology Forest Dr., The Woodlands, Texas 77381, for necessary repairs or replacement.

Terms & Conditions

• The original serial number must be legible on each sensor element base.

• Shipping point is FOB the Detcon factory.

• Net payment is due within 30 days of invoice.

• Detcon, Inc. reserves the right to refund the original purchase price in lieu of sensor replacement.

ITM Electronics Warranty

Detcon Inc. warrants, under intended normal use, each new CX-DM Sensor IT M to be free from def ects in material and workmanship for a period of one year from the date of shipment to the original purchaser. All warranties and service policies are FOB the Detcon facility located in The Woodlands, Texas.

Terms & Conditions

• The original serial number must be legible on each ITM.

• Shipping point is FOB the Detcon factory.

• Net payment is due within 30 days of invoice.

• Detcon, Inc. reserves the right to refund the original purchase price in lieu of ITM replacement.

CX-DM Instruction Manual Rev. 1.3 Page 30 of 40

Model CX-DM

8. Appendix

8.1 Specifications

System Specifications

Sensor Type: Continuous diffusion/adsorption type

3-Electrode Electrochemical Sensor (2-Electrode for O Plug-in Replaceable Type

Sensor Life: 2 years typical

Measuring Ranges: 0-1ppm up to 0-10,000ppm (Toxic Gases) 0-1% up to 0-25% volume (O

)

2

Accuracy/ Repeatability: ±2% of full-range (Toxic Gases) ±1% of full-range (O

)

2

Response Time: T90 < 30 seconds typical (See Sensor Table)

Warranty: Electronics – 1 year Sensor – See Table 3 Sensor Specific Data

Environmental Specifications

)

2

Operating Temperature: -40°C to +50°C typical (See Table 3 Sensor Specific Data ) Storage Temperature: -35°C to +55°C typical Operating Humidity: 10-95% RH Continuous Duty (See Table 3 Sensor Specific Data)

0-100% RH Short-Term Duration Only

Operating Pressure: Ambient ± 10%

Air Velocity: 0-5 meters/second

Electrical Specifications

Input Voltage: 7-30 VDC

Power Consumption: 20mW (Low Power Mode) 100mW (Typical) 500mW (Max)

RFI/EMI Protection: Complies with EN61326

Cable Requirements: Power/Analog: 3-wire shielded cable

Maximum distance is 4000 feet with 14 AWG

Power/RS-485: 4-wire two twisted pair shielded cable

Mechanical Specifications

Length: ITM - 5.165 inches (131 mm), 8.5 inches (215mm) with Splash Guard

CX-DM Instruction Manual Rev. 1.3 Page 31 of 40

Model CX-DM

Response (seconds)

O2

Oxygen

371-343400-025

T95<30

<5%signal loss/year

-20 to+50

15 to 90

2 years

C2H3O

Acetaldehyde

371-12EA00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

C2H2

Acetylene

371-12EG00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

<2%signal

loss/month

<5%signal

loss/month

<2%signal

loss/month

C4H6

Butadiene

371-12EB00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

Carbon Monoxide

<2%signal

loss/month

(>10ppm)

<2%signal

loss/month

ClO2 (<=10ppm)

<1%signal

loss/month

<5%signal

loss/month

C2H5OH

Ethanol

371-12EO00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

0

<2%signal

loss/month

C2H4

Ethylene

371-12ED00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

C2H4O

Ethylene Oxide

371-12EJ00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

F2

Fluorine

371-272700-001

T90<80

<5%signal loss/year

-10 to+40

10 to 95

1.5 years

CH2O

Formaldehyde

371-12EP00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

<1%signal

loss/month

<5%signal

loss/month

<2%signal

loss/month

<2%signal

loss/month

Hydrogen Bromide

<3%signal

loss/month

1.5 years

Hydrogen Chloride

<2%signal

loss/month

1.5 years

Hydrogen Cyanide

<5%signal

loss/month

Width: 2.2 inches (55 mm)

Weight: 2.5 lbs (1.2 Kg)

Mechanical Connection: ¾” Male NPT threaded connection with locking nut

Electrical Connection: five 18 gauge wire leads - 5.5” long

8.2 Sensor Specific Data

Table 3 Sensor Specific Data

Gas GasName Part Number1

NH3

AsH3

Br2

CO

Cl2

ClO2

B2H6

C2H5SH

Ammonia

Arsine Bromine

Chlorine Chlorine Dioxide 371-777700-001 T90<60

Chlorine Dioxide 371-282800-050 T90<120 Diborane

Ethyl Mercaptan

371-171700-100 T90<90

371-191900-001 T90<60 371-747500-005 T90<60

371-444400-100 T90=30 <5%signal loss/year -40 to+50 15 to 90 3 years

371-747400-010 T90<60

371-192100-005 T90<60

371-24EZ00-10

Time

T90<45

SpanDrift

Temperatur e Range °C

-20 to+50 15 to 90 2 years

-20 to+40 20 to 95 1.5 years

-20 to+50 15 to 90 2 years

-20 to+40 10 to 95 2 years

-20 to+40 20 to 95 1.5 years

-40 to+50 15 to 90 2 years

Humidity

Range%

Warranty

GeH4

N2H4

H2 (ppm)

H2 (LEL)*

HBr

HCl

HCN

1

The last three digits of the Part Number are the range of the sensor cell. I.E. “-100” is a 100ppm range.

CX-DM Instruction Manual Rev. 1.3 Page 32 of 40

Germane

Hydrazine Hydrogen

Hydrogen

371-232500-002 T90<60

371-262600-001 T90<120 371-848400-100 T90=30

371-050500-04P T90<60 371-090800-030 T90<70

371-090900-030 T90<70

371-131300-030 T90<40

-20 to+40 20 to 95 1.5 years

-10 to+40 10 to 95 1 year

-20 to+50 15 to 90 2 years

-40 to+40 5 to 95 2 years

-20 to+40 10 to 95

-40 to+40 5 to 95 2 years

Model CX-DM

Response (seconds)

Hydrogen Fluoride

<10%signal

loss/month

<2%signal

loss/month

CH3OH

Methanol

371-12EE00-100

T90<140

<5%signal loss/year

-20 to+50

15 to 90

2 years

Methyl Mercaptan

<2%signal

loss/month

<2%signal

loss/month

<2%signal

loss/month

<1%signal

loss/month

<1%signal

loss/month

1.5 years

<1%signal

loss/month

1.5 years

<1%signal

loss/month

1.5 years

<2%signal

loss/month

Gas GasName Part Number1

HF

H2S

CH3SH

NO

NO2

O3

COCl2

PH3

SiH4

SO2

Hydrogen Sulfide 371-242400-100 T80<30

Nitric Oxide

Nitrogen Dioxide Ozone

Phosgene Phosphine

Silane

Sulfur Dioxide

371-333300-010 T90<90

371-24EK00-100 T90<45 371-949400-100 T90=10

371-646400-010 T90<40 371-999900-001 T90<120

371-414100-001 T90<120 371-192000-005 T90<30

371-232300-050 T90<60

371-555500-020 T90=20

Time

SpanDrift

Temperatur

e Range °C

-20 to+35 10 to 80 1.5 years

-40 to+50 15 to 90 2 years

-20 to+50 15 to 90 3 years

-20 to+50 15 to 90 2 years

-10 to+40 10 to 95 2 years

-20 to+40 10 to 95

-20 to+40 20 to 95

-20 to+50 15 to 90 2 years

Humidity

Range%

Warranty

CX-DM Instruction Manual Rev. 1.3 Page 33 of 40

Model CX-DM

Dimethyl Sulfide

Methane

Acetylene

Disilane

Methanol

Acrylonitrile

Epichlorohydrin

ketone

Alcohols

Ethanol

Methyl Mercaptan

Amines

Ethyl Mercaptan

Nitric Oxide

Ammonia

Ethylene

Nitrogen

ride

Ethylene Oxide

Nitrogen Dioxide

ride

Fluorine

Ozone

Arsine

Formaldehyde

Phosgene

ide

Germane

Phosphine

Bromine

Hydrazine

Butadiene

Hydrocarbons

Silane

Hydrocarbons (unsaturated)

Silicon

Hydrogen

Silicon Tetra Fluoride

Carbon Disulfide

Hydrogen Bromide

Sulfur Dioxide

Carbon Oxide Sulfide

Hydrogen Chloride

Tetrahydrothiophene

Carbon Monoxide

Hydrogen Cyanide

Thiophane

Carbonyl Sulfide

Hydrogen Fluoride

Toluene

Chlorine

Hydrogen Selenide

Tungsten Hexafluoride

Chlorine Dioxide

Hydrogen Sulfide

Vinyl Acetate

Chlorine Trifluoride

Dimethyl Sulfide

ride

Diborane

8.3 Interference Table

Reference Table 4 Interfering Gases to match the interfering gas symbol with the gas name. Then refer to Table 5 Cross Interference Table which extends for 5 pages, with each sensor specific gas repeated in each section of the table, for a column listing of 40 gases. The list is followed by a row of 14 possible interfering gases per page. Review each page for the applicable sensor gas and then scan across the row for possible interference gases.

Table 4 Interfering Gases

Acetaldehyde C2H3O

Arsenic Trifluo

Arsenic Pentafluo

Boron Trifluor

Buten-1 Buten-1

Carbon Dioxide CO2

C2H2 C3H3N Alcohols Amines NH3 AsF3 AsF5 AsH3 BF3 Br2 C4H6

CS2 COS CO CS Cl2 ClO2 ClF3 B2H6

C2H6S Si2H6 C3H5OCl Methyl-ethylC2H5OH C2H5SH C2H4 C2H4O F2 CH2O GeH4 N2H4 Phosphorous Trifluoride PF3 C-H's C-H's (μ) H2 HBr HCl HCN HF HSe H2S C2H6S Vinyl Chlo

CH4 CH3OH C4H8O CH3SH NO N2 NO2 O3 COCl2 PH3

SiH4 Si SiF4 SO2 C4H8S C4H4S C6H5CH WF6 C4H6O2 C2H3Cl

3

CX-DM Instruction Manual Rev. 1.3 Page 34 of 40

Model CX-DM

Gas

C2H30

C2H2

C3H3N

Alcohols

Amines

NH3

AsF3

AsF5

AsH3

BF3

Br2

C4H6

Buten-1

C2H3O

n/a

40=340

40=75

n/d

40=170

n/d

C2H2

340=40

n/a

340=75

n/d

340=170

n/d

C3H3N

75=40

75=340

n/a

n/d

75=170

n/d

NH3

n/d

AsH3

n/d

100=0.01

n/d

n/a

n/d

Br2

n/d

n/a

n/d

C4H6

170=40

170=340

170=75

n/d

n/a

n/d

CS2

140=40

140=340

140=75

n/d

140=170

n/d

CO

n/d

Cl2

n/d

1=0.55

n/d

ClO2 (>10ppm)

n/d

1=0.18

n/d

ClO2 (=10ppm)

n/d

B2H6

n/d

100=0.013

n/d

0.15=0.2

n/d

C3H5OCl

50=40

50=340

50=75

n/d

50=170

n/d

C2H5OH

180=40

180=340

180=75

n/d

180=170

n/d

C2H5SH

n/d

C2H4

220=40

220=340

220=75

n/d

220=170

n/d

C2H4O

275=40

275=340

275=75

n/d

275=170

n/d

F2

n/d

1000=0

n/d

0.1=0

n/d

yes n/d

n/d

CH2O

330=40

330=340

330=75

n/d

330=170

n/d

GeH4

n/d

100=<1

n/d

0.2=0.14

n/d

N2H4

n/d

1000=0

n/d

200=0.04

n/d

0.1=0.1

n/d

H2 (ppm)

n/d

H2 (LEL)

n/d

100=0

n/d

HBr

n/d

1000=0

no

n/d

0.1=0.3

n/d

HCl

n/d

1000=0

no

n/d

0.1=0.3

n/d

HCN

n/d

1000=0

n/d

0.1=0

n/d

yes n/d

n/d

HF

n/d

1000=0

n/d

yes n/d

0.1=0

yes n/d

n/d

H2S

n/d

CH3OH

415=40

415=340

415=75

n/d

415=170

n/d

CH3SH

n/d

275=170

n/d

NO

n/d

NO2

n/d

O3

n/d

0.1=0.05

n/d

yes n/d

n/d

COCl2

n/d

1000=0

n/d

50=0.5

n/d

PH3

n/d

100=0.01

n/d

1=1

n/d

SiH4

n/d

100=<1

n/d

0.2=0.14

n/d

SO2

n/d

C4H6O2

200=40

200=340

200=75

n/d

200=170

n/d

C2H3Cl

200=40

200=340

200=75

n/d

200=170

n/d

Table 5 Cross Interference Table

n/a – not applicable n/d – no data

CX-DM Instruction Manual Rev. 1.3 Page 35 of 40

Model CX-DM

Gas

CO2

CS2

CO

COS

CL2

CLO2

CLF3

B2H6

C2H6S

Si2H6

C3H5OCL

C2H5OH

F2

C2H3O

n/d

40=140

40=100

40=135

n/d

40=150

n/d

40=50

40=180

n/d

C2H2

n/d

340=140

340=100

340=135

n/d

340=150

n/d

340=50

340=180

n/d

C3H3N

n/d

75=140

75=100

75=135

n/d

75=150

n/d

75=50

75=180

n/d

NH3

n/d

300=8

n/d

1=-1

10%=-15

n/d

AsH3

5000=0

n/d

300=0

n/d

0.5=-0.04

n/d

0.2=0.15

n/d

5=yes n/d

n/d

Br2

n/d

300=0

n/d

1=2

1=6

n/d

C4H6

n/d

170=140

170=100

170=135

n/d

170=150

n/d

170=50

170=180

n/d

CS2

n/d

n/a

140=100

140=135

n/d

140=150

n/d

140=50

140=180

n/d

CO

n/d

n/a

n/d

1=0

n/d

200=0

n/d

Cl2

n/d

300=0

n/d

n/a

n/d

ClO2 (>10ppm)

n/d

300=0

n/d

3=1

n/a

n/d

ClO2 (=10ppm)

5000=0

n/d

1000=0

n/d

1=0.9

n/a

yes n/d

0.1=0

n/d

yes n/d

B2H6

5000=0

n/d

300=0

n/d

0.5=-0.05

n/d

n/a

n/d

5=yes n/d

n/d

C3H5OCl

n/d

50=140

50=100

50=135

n/d

50=150

n/d

n/a

50=180

n/d

C2H5OH

n/d

180=140

180=100

180=135

n/d

180=150

n/d

180=50

n/a

n/d

C2H5SH

n/d

300=5

n/d

1=-0.6

n/d

C2H4

n/d

220=140

220=100

220=135

n/d

220=150

n/d

220=50

220=180

n/d

C2H4O

n/d

275=140

275=100

275=135

n/d

275=150

n/d

275=50

275=180

n/d

F2

5000=0

n/d

1000=0

n/d

1=1.3

n/d

n/a

CH2O

n/d

330=140

330=100

330=135

n/d

330=150

n/d

330=50

330=180

n/d

GeH4

5000=0

n/d

300=0

n/d

0.5=-0.04

n/d

0.2=0.11

n/d

5=yes n/d

n/d

N2H4

5000=0

n/d

1000=0

n/d

1=0

n/d

H2 (ppm)

n/d

300=<30

n/d

1=0

n/d

H2 (LEL)

1000=0

n/d

50=6

n/d

5=0

n/d

HBr

5000=0

n/d

1000=0

n/d

5=1

n/d

yes n/d

n/d

HCl

5000=0

n/d

1000=0

n/d

5=1

n/d

1=yes n/d

n/d

HCN

5000=0

n/d

1000=0

n/d

5=-1

n/d

HF

5000=0

n/d

1000=0

n/d

1=0.4

n/d

yes n/d

0.1=0

n/d

yes n/d

H2S

n/d

300==1.5

n/d

1=˜-0.2

n/d

CH3OH

n/d

415=140

415=100

415=135

n/d

415=150

n/d

415=50

415=180

n/d

CH3SH

n/d

300=3

n/d

1=-0.4

n/d

NO

n/d

300=0

n/d

1=0

n/d

NO2

n/d

300=0

n/d

1=˜1

n/d

O3

5000=0

n/d

300=0

n/d

1=1.4

0.1=0.12

1=1(theory

n/d

0.1=0.07

COCl2

5000=0

n/d

1000=0

n/d

1=0

n/d

PH3

5000=0

n/d

300=0

n/d

0.5=-0.04

n/d

0.2=0.15

n/d

5=yes n/d

n/d

SiH4

5000=0

n/d

300=0

n/d

0.5=-0.04

n/d

0.2=0.11

n/d

5=yes n/d

n/d

SO2

n/d

300=<5

n/d

1=<0.5

n/d

C4H6O2

n/d

200=140

200=100

200=135

n/d

200=150

n/d

200=50

200=180

n/d

C2H3Cl

n/d

200=140

200=100

200=135

n/d

200=150

n/d

200=50

200=180

n/d

Table 5 Cross Interference Table (pg.2)

n/a – not applicable n/d – no data

CX-DM Instruction Manual Rev. 1.3 Page 36 of 40

Model CX-DM

Gas

C2H4

C2H4O

CH2O

GeH4

N2H4

C-H's

C-H's (U)

H2

HBr

HCL

HCN

HF

I2

C2H3O

40=220

40=275

40=330

N/d

n/d

C2H2

340=220

340=275

340=330

N/d

n/d

C3H3N

75=220

75=275

75=330

N/d

n/d

NH3

100=0

n/d

N/d

n/d

200=4

n/d

5=-3

10=0

n/d

AsH3

n/d

1=0.4

n/d

%range=0

n/d

3000=0

n/d

5=0

10=0.1

4=0

n/d

Br2

100=0

n/d

N/d

n/d

100=0

n/d

5=0

10=0

n/d

C4H6

170=220

170=275

170=330

N/d

n/d

CS2

140=220

140=275

140=330

N/d

n/d

CO

100=<100

n/d

N/d

n/d

100=<60

n/d

5=0

10=<2

n/d

Cl2

100=0

n/d

N/d

n/d

100=0

n/d

5=0

10=0

n/d

ClO2 (>10ppm)

100=0

n/d

N/d

n/d

100=0

n/d

5=0

10=0

n/d

ClO2 (=10ppm)

n/d

1=0

n/d

%range=0

n/d

1%=0

n/d

B2H6

n/d

1=0.53

n/d

%range=0

n/d

3000=0

n/d

5=0

10=0.13

4=0

n/d

C3H5OCl

50=220

50=275

50=330

N/d

n/d

C2H5OH

180=220

180=275

180=330

N/d

n/d

C2H5SH

100=0

n/d

N/d

n/d

1%=<15

n/d

5=0

10=0

n/d

C2H4

n/a

220=275

220=330

n/d

C2H4O

275=220

n/a

275=330

n/d

F2

n/d

%range=0

n/d

1%=0

n/d

5=0

1=-3

3=0

n/d

CH2O

330=220

330=275

n/a

n/d

GeH4

n/d

n/a

n/d

%range=0

n/d

3000=0

n/d

5=0

10=1

4=0

n/d

N2H4

n/d

n/a

%range=0

n/d

1000=0

n/d

5=0.1

n/d

3=0

n/d

H2 (ppm)

100=˜80

n/d

n/a

n/d

5=0

10=˜3

n/d

H2 (LEL)

yes n/d

n/d

n/a

n/d

10=0

n/d

HBr

n/d

%range=0

n/d

1%=0

n/a

1=1

15=1

3=0

n/d

HCl

n/d

1=n/d

n/d

%range=0

n/d

1%=0

1=1

n/a

15=1

3=0

n/d

HCN

n/d

%range=0

n/d

1000=0

n/d

5=0

n/a

3=0

n/d

HF

n/d

1=0

n/d

%range=0

n/d

1%=0

n/d

5=3.3

n/d

n/a

n/d

H2S

100=0

n/d

1%=<5

n/d

5=0

10=0

n/d

CH3OH

415=220

415=275

415=330

n/d

CH3SH

100=0

n/d

1%=<10

n/d

5=0

10=0

n/d

NO

100=0

n/d

100=0

n/d

5=<1

10=0

n/d

NO2

100=0

n/d

100=0

n/d

5=0

10=0

n/d

O3

n/d

1%=0.003

n/d

10=0

10=0.03

5=0

yes n/d

COCl2

n/d

%range=0

n/d

1%=0

n/d

5=0

3=0

n/d

PH3

n/d

1=0.4

n/d

%range=0

n/d

3000=0

n/d

5=0

10=0.1

4=0

n/d

SiH4

n/d

1=1.0

n/d

%range=0

n/d

3000-=0

n/d

5=0

10=1

4=0

n/d

SO2

100=0

n/d

100=0

n/d

5=0

10=<5

n/d

C4H6O2

200=220

200=275

200=330

n/d

C2H3Cl

200=220

200=275

200=330

n/d

Table 5 Cross Interference Table (pg.3)

n/a – not applicable n/d – no data

CX-DM Instruction Manual Rev. 1.3 Page 37 of 40

Model CX-DM

Gas

HSe

H2S

C3H8O

CH4

CH3OH

C4H8O

CH3SH

NO

N2

NO2

O3

COCL2

PH3

C2H3O

n/d

40=415

n/d

40=275

n/d

C2H2

n/d

340=415

n/d

340=275

n/d

C3H3N

n/d

75=415

n/d

75=275

n/d

NH3

n/d

15=30

n/d

35=6

n/d

5=-1

n/d

AsH3

0.05=0.005

1=0

n/d

100%=0

n/d

0.1=0.11

Br2

n/d

15=-1.5

n/d

35=0

n/d

5=˜10

n/d

C4H6

n/d

170=415

n/d

170=275

n/d

CS2

n/d

140=415

n/d

140=275

n/d

CO

n/d

15=<0.3

n/d

35==7

n/d

5=0.5

n/d

Cl2

n/d

15=-0.75

n/d

35=0

n/d

5=˜5

n/d

ClO2 (>10ppm)

n/d

15=0.25

n/d

35=0

n/d

5=1.66

n/d

ClO2 (=10ppm)

n/d

10=-0.015

n/d

yes n/d

n/d

B2H6

0.05=0.006

1=0

n/d

100%=0

n/d

0.1=0.14

C3H5OCl

n/d

50=415

n/d

50=275

n/d

C2H5OH

n/d

180=415

n/d

180=275

n/d

C2H5SH

n/d

1:03

n/d

5=8

35=<6

n/d

5=-1.5

n/d

C2H4

n/d

220=415

n/d

220=275

n/d

C2H4O

n/d

275=415

n/d

275=275

n/d

F2

n/d

1=-1.5

n/d

100%=0

1=0.05

0.1=0.2

n/d

CH2O

n/d

330=415

n/d

330=275

n/d

GeH4

0.05=0.005

1=0

n/d

100%=0

n/d

0.1=0.13

N2H4

n/d

1=0.1

n/d

100%=0

1=-0.25

0.1=-0.1

n/d

0.3=0.1

H2 (ppm)

n/d

15=<3

n/d

35=˜10

n/d

5=0

n/d

H2 (LEL)

n/d

yes n/d

1%=0

n/d

yes n/d

n/d

10=0

n/d

HBr

0.1=0

10=2.75

n/d

100%=0

n/d

0.1=0

0.1=0.3

HCl

0.1=0

10=2.75

n/d

100%=0

n/d

0.1=0

0.1=0.3

HCN

n/d

10=0

n/d

100%=0

10=-12

0.1=0

n/d

0.3=0

HF

n/d

10=0

n/d

100%=0

10˜0.1

n/d

0.1=0

H2S

n/d

n/a

n/d

2:01

35=<2

n/d

5=-0.5

n/d

CH3OH

n/d

n/a

n/d

415=275

n/d

CH3SH

n/d

1:02

n/d

n/a

35=<4

n/d

5=-1.0

n/d

NO

n/d

15=˜5

n/d

100=0

n/d

5=<1.5

n/d

NO2

n/d

15=-0.75

n/d

35=0

n/d

n/a

n/d

O3

n/d

1=-.015

n/d

10=0

100%=0

1=0.7

n/a

n/d

0.3=0.03

COCl2

n/d

1=0

n/d

100%=0

n/d

n/a

0.3=0

PH3

0.05=0.005

1=0

n/d

100%=0

n/d

n/a

SiH4

0.05=0.005

1=0

n/d

100%=0

n/d

0.1=0.13

SO2

n/d

15=0

n/d

35=0

n/d

5=˜-5

n/d

C4H6O2

n/d

200=415

n/d

200=275

n/d

C2H3Cl

n/d

200=415

n/d

200=275

n/d

Table 5 Cross Interference Table (pg.4)

n/a – not applicable n/d – no data

CX-DM Instruction Manual Rev. 1.3 Page 38 of 40

Model CX-DM

Gas

PF3

SiH4

Si

SiF4

SO2

C4H8S

C4H4S

C6H5CH3

WF6

C4H6O2

C2H3CL

C2H5SH

C6H5CH3

C2H3O

n/d

40=45

n/d

40=200

n/d

40=55

C2H2

n/d

340=45

n/d

340=200

n/d

340=55

C3H3N

n/d

75=45

n/d

75=200

n/d

75=55

NH3

n/d

5=-0.5

n/d

AsH3

n/d

1=0.56

n/d

2=0

n/d

Br2

n/d

5=-0.1

n/d

C4H6

n/d

170=45

n/d

170=200

n/d

170=55

CS2

n/d

140=45

n/d

140=200

n/d

140=55

CO

n/d

5=0

n/d

Cl2

n/d

5=-0.05

n/d

ClO2 (>10ppm)

n/d

5=-0.016

n/d

ClO2 (=10ppm)

n/d

B2H6

n/d

1=0.72

n/d

2=0

n/d

C3H5OCl

n/d

50=45

n/d

50=200

n/d

50=55

C2H5OH

n/d

180=45

n/d

180=200

n/d

180=55

C2H5SH

n/d

5=<3

n/d

n/a

n/d

C2H4

n/d

220=45

n/d

220=200

n/d

220=55

C2H4O

n/d

275=45

n/d

275=200

n/d

275=55

F2

n/d

2=0

n/d

CH2O

n/d

330=45

n/d

330=200

n/d

330=55

GeH4

n/d

1=1

n/d

2=0

n/d

N2H4

n/d

2=0

n/d

H2 (ppm)

n/d

5=0

n/d

H2 (LEL)

n/d

2=0

n/d

HBr

n/d

5=2.5

n/d

HCl

n/d

5=2.5

n/d

HCN

n/d

2=0

n/d

HF

yes n/d

n/d

3=4(theory)

yes n/d

n/d

yes n/d

n/d

H2S

n/d

5=<1

n/d

3=1

n/d

CH3OH

n/d

415=45

n/d

415=200

n/d

413=55

CH3SH

n/d

5=<2

n/d

2=1

n/d

NO

n/d

5=0

n/d

NO2

n/d

5=-0.025

n/d

O3

n/d

1=0.015

n/d

2=0

n/d

COCl2

n/d

2=0

n/d

PH3

n/d

1=0.56

n/d

2=0

n/d

SiH4

n/d

n/a

n/d

2=0

n/d

SO2

n/d

n/a

n/d

C4H6O2

n/d

200=45

n/d

n/a

200=200

n/d

200=55

C2H3Cl

n/d

200=45

n/d

200=200

n/a

n/d

200=55

Table 5 Cross Interference Table (pg.5)

n/a – not applicable n/d – no data

CX-DM Instruction Manual Rev. 1.3 Page 39 of 40

Model CX-DM

92C-240400-000

CX-DM-H2S Intelligen t Tr a nsmitter Modul e

92C-XX0400-YYY

CX-DM Intelligent Transmitter Module for Toxic Gas Sensors (where xx=Gas Code, and YYY=Range)

371-XXXX00XXX

Replacement Plug-in toxic gas sensor (Refer to Table 3 Sensor Specific Data)

613-120000-700

Sensor Splash Guard with integral Cal Port

602-003803-000

CX-DM Splashguard Adapter Assembly

602-003803-200

CX-DM H2S Splashguard Adapter Assembly

943-002273-000

Harsh Environment Sensor Guard

327-000000-000

Programming Magnet

943-000000-000

Calibration Wind Guard

943-000006-132

Threaded Calibration Adapter

943-01747-T05

Calibration Adapter for highly reactive gases

943-050000-132

Span Gas Kit: Includes calibration adapter, span gas humidifier, 500cc/min fixed flow regulator, and carrying case. (Not including gas).

943-050000-HRG

Highly Reactive Gas Span Gas Kit (Used for NH3, Cl2, HCl, HBr, etc.)

See Detcon

Span Gases – various

943-05AM00-000

500 cc/min Fixed Flow Regulator for span gas bottle

897-860000-316

316SS Mini Condulet w/Solid Cover

960-202200-000

Condensation prevention packet (For condulet, replace annually)

Revision

Date

Changes made

Approval

1.0

03/20/13

Release

LBU

1.1

01/29/14

Update wiring, calibration and other corrections

LBU

1.2

04/09/14

Wiring Correction

LBU

1.3

05/29/14

Added Section 2.1, Updated Approvals Label

BM

Shipping Address: 4055 Technology Forest, Suite 100, The Woodlands, Texas 77381

Phone: 713.559.9200 • Fax: 281.292.2860 •www.detcon.com • sales@detcon.com

8.4 Spare Parts, Sensor Accessories, Cal ibration Eq uipment

Part Number Spare Parts

Part Number Sensor Accessories

Part Number Calibration Accessories

Part Number Optional Accessories

8.5 Revision Log

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

CX-DM Instruction Manual Rev. 1.3 Page 40 of 40

Detcon CX-DM User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Table of Figures

List of Tables

1. Introduction

1.1 Description

Electrochemical Sensor Technology

Principle of Ope r at io n

1.2 Modular Design

CX-DM Intelligent Transmitter Module

Field Replaceable Sensor

2. Installation

2.1 Hazardous Location s Installation Guidelines for Safe Use

2.2 Sensor Placement

2.3 Sensor Cont aminants and Interferen ce

Cross-Interference Data T ab le

2.4 Sensor Mounting

2.5 Electrica l Installation

2.6 Field Wiring

2.6.1 Terminal Connections 3-Wire 4-20mA

2.6.2 Terminal Connections 4-20mA and RS-485

2.7 Initial Start Up

Material Requirements

2.7.1 O2 Deficiency Sensors

Initial Operational Tests

3. Operation

3.1 Operator Interface

Normal Operation

Calibration Mode

Program Mode

Software Flowchart

3.2 Normal Operation

3.3 Calibration Mode

3.3.1 AutoZero

Zero Cal. . . Setting Zero. . . Zero Saved ( each will scroll twice)

3.3.2 AutoSpan

Material Requirements:

3.4 Program M ode

Navigating Program Mode

3.4.1 View Sensor Status

3.4.2 Set Detection Range

3.4.3 Set AutoSpan Level

3.4.4 Bump Test

3.4.5 Restore Defaults

3.4.6 Set Modbus ID

3.5 Fault Diagnostic/Failsafe Feature

4. Modbus™ Communications

4.1 General Modbu s™ De scr ip ti on

4.2 Modbus™ Register Map & Description

4.2.1 Sensor Faults – Register 40005

4.2.2 Temperature Compensation – Register 40012

5. Service and Maintenance

5.1 Replacement of Plug-in Sensor

5.2 Replacement of ITM – Aluminum J-Box

5.3 Replacement of ITM – Stainless Steel Mini Condulet

6. Troubleshooting Guide

6.1 Under-Range problems

6.2 Stability problems

6.3 Clearing problem

6.4 Poor Calibration Repeatability

6.5 Unstable Output/ sudden spiking

6.6 Nuisance Alarms

6.7 Intelligent Transmitter Module (ITM) not respondin g

7. Customer Support and Service Policy

7.1 Warranty Notice

7.2 CX-DM Sensor Warranty

8. Appendix

8.1 Specifications

System Specifications

Environmental Specifications

Electrical Specifications

Mechanical Specifications

8.2 Sensor Specific Data

8.3 Interference Table

8.4 Spare Parts, Sensor Accessories, Cal ibration Eq uipment

8.5 Revision Log