Ampcontrol Gasguard 65-6551-CH4 Series User manual

User Manual Part Number: 165714
Version: 6, March 2019
Designed and manufactured in Australia by Ampcontrol Pty Ltd
CATALYTIC METHANESENSOR
ATEXCERTIFIEDMODEL
UserManual

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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WARNING!
The warning symbol highlights a potential risk of injury or death.
Please share these warnings with other operators.
CAUTION!
The caution symbol highlights a potential risk of damage to
equipment.
Please share these cautions with other operators.
NOTE
The note symbol highlights key information.
Please share these notes with other operators.
ENVIRO
The enviro (environmental) symbol highlights areas which may have an
impact on the surrounding fauna and/or flora.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Copyright Notice
The Ampcontrol Gasguard Sensor described in this document is the propertyof AMPCONTROL PTY LTD.
It is furnished under a license agreement and is to be used only in accordance with the terms of the
agreement.
No part of the hardware or documentation may be reproduced, transmitted, transcribed, stored in a
retrieval system, or translated into any language or computer language, in any form or by any means,
without prior written permission of AMPCONTROL PTY LTD.
Disclaimer
While every effort has been made to assure the accuracy and clarity of this document, AMPCONTROL
PTY LTD assumes no liability resulting from any omissions in this document, or from misuse of the
information obtained herein. The information in this document has been carefully checked and is believed
to be entirely reliable with all of the necessary information included. AMPCONTROL PTY LTD reserves
the right to make changes to any products described herein to improve reliability, function, or design, and
reserves the right to revise this document and make changes from time to time in content hereof with no
obligation to notify any persons of revisions or changes. AMPCONTROL PTY LTD does not assume any
liability arising out of the application or any use of any product or circuit described herein; neither does it
convey license under its patent rights or the rights of others.
Before You Begin
Thank you for purchasing the Ampcontrol Gasguard Sensor.
WARNING!
In the interests of safety and correct equipment operation, please
take the time to read and understand the content in this manual.
Ampcontrol Contact Details
7 Billbrooke Close, Cameron Park, NSW, 2285
P [phone] | F [phone]
EMAIL: [e-mail]
WEB: ampcontrolgroup.com

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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TABLE OF CONTENTS
1 SAFETY AND OTHER WARNINGS..................................................................6
1.1 Safe Use of Equipment..............................................................................6
2 RECEIVING AND STORAGE............................................................................7
2.1 Receiving...................................................................................................7
2.2 Inspection..................................................................................................7
2.3 Storage after Delivery................................................................................7
2.4 Unpacking of Equipment............................................................................7
3 PRODUCT OVERVIEW ....................................................................................8
3.1 Sensor Details ...........................................................................................9
3.2 Amplifier Electronics PCB........................................................................10
3.3 Enclosures...............................................................................................10
4 INSTALLATION...............................................................................................11
4.1 General Warnings....................................................................................11
4.2 Product Safety Markings..........................................................................11
4.3 Recommendations...................................................................................12
4.4 Sensor Location.......................................................................................12
4.5 Mandatory Installation Practices ..............................................................12
4.6 Mechanical Installation Information..........................................................13
4.7 Electrical Installation Information .............................................................14
5 COMMISSIONING AND CALIBRATION .........................................................15
5.1 Preliminary Checks..................................................................................15
5.2 Gasguard Display Panel..........................................................................15
5.3 Sensor Calibration...................................................................................16
5.4 Zero Calibration.......................................................................................17
5.5 Span Calibration......................................................................................17
6 SERVICE, MAINTENANCE & DISPOSAL.......................................................18
6.1 Equipment Service...................................................................................18
6.2 Equipment Maintenance..........................................................................19
6.3 Disposal...................................................................................................20
7 SPECIFICATIONS ..........................................................................................21
8 EQUIPMENT LIST ..........................................................................................21
APPENDIX A: ATEX CERTIFICATION ..............................................................22

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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TABLE OF FIGURES
Figure 3.1: Gasguard CH4 Sensor Stainless Steel Housing...............................10
Figure 4.1: Catalytic Sensor Dimensions............................................................13
Figure 4.2: Electrical Connection Diagram .........................................................14
Figure 4.3: Analogue Output Maximum Loop Resistance...................................14
Figure 5.1: Gasguard Sensor Control Panel.......................................................17
TABLE OF TABLES
Table 1: Sensor Cell Cross Sensitivity..................................................................9
Table 2: Gasguard Sensor Display Status Codes...............................................15
Table 3: Manufacturer’s Periodic Maintenance Recommendation ......................19
Table 4: Corrective Maintenance –Possible Faults............................................20

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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1 SAFETY AND OTHER WARNINGS
For safety reasons, the Gasguard CH4 Sensor must be installed, operated and serviced only by
competent personnel. Please read and understand this instruction manual completely before installing,
operating or servicing this equipment. Failure to install or operate this instrument in accordance with the
instructions contained in this manual may create hazardous operating conditions.
WARNING!
The sensors should not be stored in areas that contain solvent vapours.
Some of these vapours are known to create false "high" zero points and
may even damage the sensor electrodes. Similarly, the sensor should
not be exposed to high levels of solvent vapours while in operation.
WARNING!
This equipment has been designed to detect explosive gases and
vapours and to give warning before they reach dangerous conditions.
1.1 Safe Use of Equipment
The equipment supplied has been designed and manufactured to ensure safe operation. The equipment
must only be used within the design parameters.
The instructions within this manual must be observed as an aid towards achieving the safest possible
installation.
Persons responsible for installation, maintenance, or operation, must observe the following
instructions:
1.1.1 Changes to Equipment
Changes in the design and modifications to the equipment are not permitted. Unauthorised changes
made to the hardware or operating firmware will void the manufacturer's warranty, and may
compromise the integrity of the system into which it is installed and other connected equipment.
1.1.2 Equipment Knowledge
Experience with, or understanding of, this equipment is essential for the safe installation and removal of
the equipment. Therefore, please read and understand this manual prior to use. Competency based
training courses are recommended and are available on request.
1.1.3 Manual Handling
Precautions have been taken to ensure all equipment is safe to handle and free from sharp edges.
However care should always be taken when handling enclosures and gloves should be worn.
1.1.4 Installation
Correct operation and safety depend on the Gasguard CH4 Sensor and associated equipment being
installed correctly. Mechanical and or electrical installation and maintenance of plant and equipment
must only be carried out by appropriately qualified personnel and must be tested thoroughly prior to
operation.
1.1.5 Operation
As safety depends on the Gasguard CH4 Sensor functioning correctly it is highly recommended that all
safety functions of the unit be periodically tested to ensure correct operation.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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2 RECEIVING AND STORAGE
2.1 Receiving
All possible precautions are taken to protect the equipment against damage or losses during shipment,
however before accepting delivery, check all items against the packing list or bill of loading. If there is
evidence of physical damage, notify Ampcontrol immediately.
Notify Ampcontrol immediately in case of any discrepancies to the packing list. Keep a record of any
claims and correspondence. Photographs are recommended.
Where practicable do not remove protective covers prior to installation unless there are indications of
damage. Boxes opened for inspection and inventory should be carefully repacked to ensure protection of
the contents or else the parts should be packaged and stored in a safe place. Examine all packing
boxes, wrappings and covers for items attached to them, retain and store any approval documentation
for your safety file as applicable prior to wrapping being discarded.
2.2 Inspection
Equipment that is found to be damaged or has been modified away from its published specification must
not be used. Please contact Ampcontrol if the equipment is suspected to be different than that ordered or
if it does not match the published specifications.
2.3 Storage after Delivery
When the equipment is not to be installed immediately, proper storage is important to ensure protection
of equipment and validity of warranty.
All equipment should be stored indoors between 0-40˚C, preferably on shelves and protected from
moisture and sunlight.
2.4 Unpacking of Equipment
The method of packing used will depend on the size and quantity of the equipment. The following
cautions should be interpreted as appropriate.
CAUTION!
Take care when unpacking crates as the
contents may have shifted during transport.
ENVIRO
The disposal of packaging materials, replaced parts, or components
must comply with environmental restrictions without polluting the soil,
air or water.
Ensure that any timber and cardboard used as packaging is disposed
of in a safe and environmentally responsible manner.
Where possible, dispose of all waste products i.e. oils, metals, plastic
and rubber products by using an approved recycling service centre.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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3 PRODUCT OVERVIEW
Ampcontrol’s Gasguard Flammable Gas Sensor/Transmitter is supplied complete with an amplifier and a
Liquid Crystal Display.
The Gas sensor is housed in a cast stainless steel enclosure, has been approved to be intrinsically safe
and is suitable for use in a Zone 0 hazardous area. A remote head version with up to ten metres of cable
is also available for use on mobile machinery such as roof bolters and continuous miners.
Key Features
Rugged Construction
Reliable
Certified Intrinsically Safe –Ex ia
LCD Display
Non-Intrusive Closed Case Calibration
NOTE
This manual provides commissioning, calibration and maintenance
instructions for the Ampcontrol Gasguard Sensor Units. Because the
units are passive monitoring devices, operating instructions are not
applicable to this equipment.
NOTE
The chemical symbols for toxic-gases and oxygen are used extensively
throughout this manual.
The Gasguard sensor units consist of:
Catalytic - Methane Sensor (CH4)
Amplifier PCB
For which the following instructions and diagrams are included in this manual:
Amplifier PCB Description
Sensor Wiring Diagrams
Stainless Steel Housing Enclosure Dimensions
Unique part numbers in accordance with the following scheme identifies the sensor unit configurations:
See section 8 for Catalytic sensor Item Numbers.
NOTE
In the part numbers listed, CH4 represents the chemical symbol for
methane, the gas detected by this sensor.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
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3.1 Sensor Details
3.1.1 Methane Gas Sensor
The Methane Gas Sensor, which operates on the catalytic combustible gas detection principle, is a
small platinum element coated in a catalyst. Electrical current is passed through the platinum wire and
the potential of the catalytic element is monitored by a simple Wheatstone Bridge arrangement.
Combustible gases, once in contact with the heated catalytic surface of the measuring element, react
and cause the surface temperature of the element to rise. Any increase in temperature affects the
resistance of the platinum wire, causing a small shift in potential across the Wheatstone Bridge
proportional to the concentration of the combustible gas. The sensor is temperature compensated and
provides a 4/20mA linear output.
3.1.2 Sensor Cell Cross Sensitivity
Methane gas sensors positively detect the presence of all flammable gases. It is unable to distinguish
the difference between gases so the sensor will display a reading if any flammable gas is present. The
table below details the cross sensitivity data for a methane sensor.
Table 1: Sensor Cell Cross Sensitivity
Gas
Concentration
Reading (%v/v)
Acetic Acid
4.0%
1.45
Acetone
2.6%
2.5
Ammonia
15%
6.25
Benzene
1.2%
2.0
n-Butane
1.8%
2.5
Carbon Monoxide
12.5%
4.0
Chlorobenzene
1.3%
1.7
Ethanol
3.3ppm
2.95
n-Hexane
1.2%
2.0
Hydrogen
4.0%
4.0
Methane
5.0%
5.0
Methanol
6.7%
4.25
n-Pentane
1.4%
2.0
Propane
2.1%
2.5
Toluene
1.2%
2.0
3.1.3 Poisoning of Sensors (Contamination)
High levels of or long exposure to certain compounds may poison the catalytically active detector
filament thereby reducing or destroying its sensitivity.
Among these compounds are halides, sulphur compounds, leaded petrol, silanes, silicates and other
produces with silicon. Products such as aerosol sprays, polishes, waxes and lubricants with silicones
and non-catalysed silicone rubbers such as “silastic”, phosphate esters and hydraulic fluids all damage
catalytic sensors.
CAUTION!
Exposure to Hydrogen Sulphide gas (H2S) may affect the performance
of the detector by reducing its sensitivity to methane. If the sensor is
exposed to H2S gas then the detector must be recalibrated.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GASGUARD CH4 GAS SENSOR USER MANUAL
GSB076 Version 6 –March/2019
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3.2 Amplifier Electronics PCB
The purpose of the amplifier electronics is to convert the low-level electrical output of the sensor into a
signal capable of driving external indicator equipment such as the Ampcontrol Gasguard 4 Channel
Controller.
The Gasguard amplifier electronics are designed to operate as a 3-wire unit with connections provided
for input power, power supply return and current loop signal output.
The electronics require 12VDC operating voltage and transmits a signal in the range of 4 - 20mA. The
4mA signal level indicates a zero gas concentration. The 20mA signal indicates that the sensor cell has
detected a full span gas concentration. ZERO and SPAN adjustment reed relays located on the PCB are
used for calibration of the sensor.
3.3 Enclosures
Stainless Steel Housing
The standard Stainless Steel Housing, Item Number 23-6550LB, incorporates the Sensor Cell and
Amplifier PCB. The housing is robust and is corrosion resistant. It is suitable for almost all applications
and provides for easy installation and maintenance. When properly used it gives many years of efficient
operation.
Figure 3.1: Gasguard CH4 Sensor Stainless Steel Housing