Teledyne Detcon IR-700 User manual

INSTRUCTION MANUAL
Detcon Model IR-700
IR-700 Combustible Gas Sensor
0-100% LEL and 0-50% LEL range
IR-700 CO2 Carbon Dioxide Gas Sensor
All Ranges
November 11, 2019 • Document #3169 • Revision 4.4

Model IR-700
Model IR-700 ii
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Model IR-700
Model IR-700 iii
Table of Contents
1. Introduction ..................................................................................................................................................1
1.1 Description.......................................................................................................................................... 1
1.1.1 Non-Dispersive Infrared (NDIR) Optical Sensor Technology ....................................................... 1
1.1.2 Principle of Operation .................................................................................................................... 2
1.1.3 Performance Characteristics ........................................................................................................... 2
1.2 Sensor Electronics Design .................................................................................................................. 3
1.2.1 Intelligent Transmitter Module....................................................................................................... 3
1.3 Modular Mechanical Design............................................................................................................... 3
1.4 Plug-in Replaceable Sensor ................................................................................................................ 4
2. Installation ....................................................................................................................................................5
2.1 Operational Guidelines for Safe Use – HazLoc Certifications ........................................................... 5
2.2 Sensor Placement ................................................................................................................................ 6
2.3 Sensor Contaminants and Interference ............................................................................................... 7
2.4 Mounting Installation.......................................................................................................................... 7
2.5 Electrical Installation ........................................................................................................................ 10
2.6 Field Wiring...................................................................................................................................... 11
2.7 Initial Start Up................................................................................................................................... 13
3. Operation ....................................................................................................................................................15
3.1 Programming Magnet Operating Instructions................................................................................... 15
3.2 Operator Interface ............................................................................................................................. 16
3.3 Normal Operation ............................................................................................................................. 17
3.4 Calibration Mode (AutoZero and AutoSpan) ................................................................................... 18
3.4.1 AutoZero....................................................................................................................................... 18
3.4.2 AutoSpan ...................................................................................................................................... 18
3.5 Program Mode .................................................................................................................................. 20
3.5.1 View Sensor Status....................................................................................................................... 21
3.5.2 Set AutoSpan Level ...................................................................................................................... 22
3.5.3 Set Gas Type& Range .................................................................................................................. 23
3.5.4 Set Gas Factor............................................................................................................................... 23
3.5.5 Set Serial ID ................................................................................................................................. 24
3.5.6 Set Sensor Gain ............................................................................................................................ 25
3.5.7 Signal Output Check..................................................................................................................... 25
3.5.8 Restore Factory Defaults .............................................................................................................. 26
3.6 Program Features .............................................................................................................................. 26
3.6.1 Operational Features..................................................................................................................... 27
3.6.2 Fault Diagnostic/Fail-Safe Features ............................................................................................. 27
4. RS-485 Modbus™ Protocol .......................................................................................................................30
Content Description.............................................................................................................................................30
5. Service and Maintenance............................................................................................................................32
5.1 Calibration Frequency....................................................................................................................... 32
5.2 Visual Inspection .............................................................................................................................. 32
5.3 Condensation Prevention Packet....................................................................................................... 32
5.4 Replacement of IR Plug-in Combustible Gas Sensor ....................................................................... 32
5.5 Replacement of ITM ......................................................................................................................... 33
5.6 Replacement of IR-700 Sensor Assembly ........................................................................................ 34
6. Troubleshooting Guide...............................................................................................................................35
7. Customer Support and Service Policy ........................................................................................................38
8. IR-700 Sensor Warranty.............................................................................................................................39
9. Appendix ....................................................................................................................................................40
9.1 Specifications.................................................................................................................................... 40
9.2 Spare Parts, Sensor Accessories, Calibration Equipment ................................................................. 43

Model IR-700
Model IR-700 iv
10. Revision Log ......................................................................................................................................... 44
Table of Figures
Figure 1 Sensor Cell Construction ....................................................................................................................... 1
Figure 2 Principle of Operation............................................................................................................................ 2
Figure 3 Response Curve ..................................................................................................................................... 2
Figure 4 ITM Circuit Functional Block Diagram................................................................................................. 3
Figure 5 Sensor Assembly Front View ................................................................................................................ 3
Figure 6 Sensor Assembly Breakaway................................................................................................................. 4
Figure 7 IR Sensor Cell ........................................................................................................................................ 4
Figure 8 HazLoc Certification Approval Label................................................................................................... 5
Figure 9 Outline and Mounting Dimensions (Sensor Assembly only)................................................................. 8
Figure 10 Outline and Mounting Dimensions (Stainless Steel Junction Box) ..................................................... 9
Figure 11 Outline and Mounting Dimensions (Aluminum Junction Box)........................................................... 9
Figure 12 Outline and Mounting Dimensions (Mini Stainless Steel Junction Box) .......................................... 10
Figure 13 Typical Installation ............................................................................................................................ 11
Figure 14 Sensor Wire Connections................................................................................................................... 12
Figure 15 Magnetic Programming Tool............................................................................................................. 15
Figure 16 Magnetic Programming Switches ...................................................................................................... 15
Figure 17 IR-700 Software Flowchart................................................................................................................ 17
Figure 18 Sensor Assembly................................................................................................................................ 32
List of Tables
Table 1 Wire Gauge vs. Distance ....................................................................................................................... 12
Table 2 Gas Factors............................................................................................................................................ 24
Table 3 Modbus™ Registers .............................................................................................................................. 30
Table 4 Modbus™ Special Registers ................................................................................................................. 31
Shipping Address: 4055 Technology Forest Blvd., The Woodlands Texas 77381
Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067
Phone: [phone] • www.teledynegasandflamedetection.com • [email protected]

Model IR-700
IR-700 Instruction Manual Rev. 4.4 Page 1 of 45
1. Introduction
1.1 Description
Detcon Model IR-700 combustible gas sensors are non-intrusive “Smart” sensors
designed to detect and monitor combustible hydrocarbon gases in air. The range of
detection is 0-100% LEL or 0-50% LEL. The Model IR-700 CO2Sensor is designed to
detect CO2in air at ranges from 0-.3% to 0-100% by Volume. The sensor features an
LED display of current reading, fault and calibration status. The unit is equipped with
standard analog 4-20mA and Modbus™ RS-485 outputs. A primary feature of the sensor
is its method of automatic calibration, which guides the user through each step via fully
scripted instructions shown on the LED display.
The microprocessor-supervised electronics are packaged in an encapsulated module and
housed in an explosion proof casting. The unit includes a 4 character alpha/numeric LED
used to display sensor readings and the sensor’s menu-driven interface when the hand-
held programming magnet is used.
1.1.1 Non-Dispersive Infrared (NDIR) Optical Sensor Technology
The sensor technology is designed as a miniature plug-in replaceable component, which can easily be changed
out in the field. The NDIR sensor consists of an infrared lamp source, two pyro electric detectors, and an optical
gas sample chamber. The lamp source produces infrared radiation, which interacts with the target gas as it is
reflected through the optical gas sample chamber. The infrared radiation contacts each of the two pyro electric
detectors at the completion of the optical path. The “active” pyro electric detector is covered by a filter specific
to the part of the IR spectrum where the target gas absorbs light. The “reference” pyro electric detector is covered
by a filter specific to the non-absorbing part of the IR spectrum. When the target gas is present, it absorbs IR
radiation and the signal output from the active detective decreases accordingly. The reference detector output
remains unchanged. The ratio of the active and reference detector outputs are then used to compute the target
gas concentration.
The technique is referred to as non-selective and may be used to monitor most any combustible hydrocarbon
gas. The technique for CO2is similar except that the sensor provides a selective response to CO2. Unlike
catalytic bead type sensors, Detcon IR sensors are completely resistant to poisoning from corrosive gases and
they can operate in the absence of an oxygen background. The sensors are characteristically stable and capable
of providing reliable performance for periods exceeding 5 years in most industrial environments.
Figure 1Sensor Cell Construction