Ampcontrol Gasguard GG2 DISPLAY Product manual

Version: 1, November 2020
Designed and manufactured in Australia by Ampcontrol Pty Ltd
GG2 Detector
RealtimeGasMonitoring
Design,Installationand
MaintenanceGuide

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 2 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
WARNING!
The warning symbol highlights a potential risk malfunction or loss of
performance
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
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 3 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Copyright Notice
The Ampcontrol GG2 Real Time Gas Monitoring System described in this document is the property of
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 any
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 from the Ampcontrol GG2 range.
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
NOTE
Ampcontrol’s Field service and operational teams are available to
support customers in emergency situations 24 hours a day, 7 days a
week.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 4 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
TABLE OF CONTENTS
DEFINITIONS ......................................................................................................8
1 SAFETY AND OTHER WARNINGS................................................................10
1.1 Safe Use of Equipment............................................................................10
1.2 Supplementary Documentation................................................................10
2 RECEIVING AND STORAGE..........................................................................11
2.1 Receiving.................................................................................................11
2.2 Inspection................................................................................................11
2.3 Storage after Delivery..............................................................................11
2.4 Unpacking of Equipment..........................................................................11
3 DESIGN PRINCIPLES ....................................................................................12
3.1 Planning and Designing RTGMS’s...........................................................12
3.2 Real Time Detectors as part of a safety system.......................................13
4 TYPICAL FLAMMABLE AND TOXIC GASES IN COAL MINES......................14
4.1 Methane (CH4).........................................................................................14
4.2 Hydrogen Sulphide (H2S).........................................................................14
4.3 Carbon Monoxide (CO)............................................................................14
4.4 Carbon Dioxide (CO2)..............................................................................14
4.5 Sulphur dioxide (SO2) ..............................................................................14
4.6 Nitrogen dioxide (NO2).............................................................................14
5 REAL TIME GAS MONITORING SYSTEM SAFETY GUIDELINES ................15
5.1 Risk Analysis Guidelines..........................................................................15
6 DETECTOR PRINCIPLES ..............................................................................16
6.1 Detector Filter Elements ..........................................................................16
6.2 Maintenance Considerations....................................................................16
7 INSTRUMENTATION TIME OF RESPONSE (t90)..........................................17
7.1 Detector Blockages..................................................................................19
7.2 Response Time @ Different Concentrations............................................19
7.3 Response Time to a Set Alarm or Trip Point............................................20
7.4 Gastrack Simulation –Ventilation/Gas Outburst Distribution....................20
7.5 Response Time Inspection/Test Criteria ..................................................21
8 COMMISSIONING AND CALIBRATION .........................................................22
8.1 Preliminary Checks..................................................................................22
8.2 System Adjustments................................................................................22
8.3 Electrochemical and Catalytic ZERO Test ...............................................25
8.4 Electrochemical and Catalytic SPAN Test................................................28
8.5 Non Dispersive Infrared ZERO and SPAN Adjustment ............................29

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 5 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
8.6 Response Test.........................................................................................31
8.7 Telemetry Test.........................................................................................35
8.8 ILAC Linearity Test ..................................................................................37
8.9 Calibration Troubleshooting.....................................................................40
9 SERVICE, MAINTENANCE & DISPOSAL.......................................................41
9.1 Equipment Service...................................................................................41
9.2 Equipment Maintenance..........................................................................42
9.3 Disposal...................................................................................................44
10 REFERENCED STANDARDS and RESOURCES.........................................45

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 6 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
TABLE OF FIGURES
Figure 1: GG2 Example System (iMAC Communication)........................................................................13
Figure 2: Factors Effecting Response Times..........................................................................................16
Figure 3: Detector Blockages .................................................................................................................19
Figure 4: Response Time @ Different Concentrations............................................................................19
Figure 5: Response Time to a Set Alarm or Trip Point............................................................................20
Figure 6: Gastrack Simulation ................................................................................................................20
Figure 7: Maintenance............................................................................................................................26
Figure 8: Gas Calibration........................................................................................................................27
Figure 9: Zero Adjustment –Apply Zero Gas..........................................................................................27
Figure 10: Zero Adjustment –Set Zero...................................................................................................27
Figure 11: Zero Adjustment –Saving Changes ......................................................................................27
Figure 12: Span Adjustment –Span Value.............................................................................................29
Figure 13: Span Adjustment –Saving Changes .....................................................................................29
Figure 14: Gas Calibration......................................................................................................................30
Figure 15: Gas Calibration –Warning.....................................................................................................30
Figure 16: Scaling Adjustment –Apply Zero Gas ...................................................................................30
Figure 17: Scaling Adjustment –Set Zero ..............................................................................................31
Figure 18: Scaling Adjustment –Apply Span Gas ..................................................................................31
Figure 19: Scaling Adjustment –Span Value..........................................................................................31
Figure 20: Response Test - Target Entry................................................................................................33
Figure 21: Response Test –Instructions ................................................................................................34
Figure 22: Testing & Calibration.............................................................................................................34
Figure 23: Response Test - Apply Cup...................................................................................................34
Figure 24: Response Test - Timer..........................................................................................................35
Figure 25: Response Test –Result ........................................................................................................35
Figure 26 Telemetry Test Screen: ..........................................................................................................37
Figure 27: Telemetry Test Underway......................................................................................................37
Figure 28: Linearity Test - Instruction Screen.........................................................................................38
Figure 29: Linearity Test - Waiting for Stabilisation.................................................................................38
Figure 30: Linearity Test - Input Gas Concentration ...............................................................................38
Figure 31: Linearity Test - Check Point One Saving ...............................................................................39
Figure 32: Linearity Test - Confirmation..................................................................................................39
Figure 33: Linearity Test - Testing Complete..........................................................................................39

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 7 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
TABLE OF TABLES
Table 1: Recommended Calibration Gases............................................................................................25
Table 2: Specified Value for Various Gases ...........................................................................................26
Table 3: Response time determination ...................................................................................................32
Table 4: Telemetry Test Target Values...................................................................................................35
Table 5: AS/NZS2290.3.2018 - Schedule of Inspection and Tests..........................................................43
Table 6: Corrective Maintenance Checks...............................................................................................44

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 8 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
DEFINITIONS
Term
Definition
CO2
Carbon Dioxide
CH4
Methane
CO
Carbon Monoxide
O2
Oxygen
H2S
Hydrogen Sulphide
NATA
National Association of Testing Authorities, Australia
NDIR
Non-Dispersive Infrared
Warm Up Time
Time interval, with the equipment in a stated atmosphere, between the time
when the equipment is switched on and the time when the indication reaches
and remains within the stated tolerances
AS/NZS 4641:2007
Electrical apparatus for detection of oxygen and other gases and vapours at
toxic levels - general requirements and test methods
AS/NZS 2290.3-
2018
Electrical equipment for coal mines- maintenance and overhaul Part 3:
maintenance of gas detecting and monitoring equipment.
AS/NZS 2290.3-
1990
Electrical equipment for coal mines - maintenance and overhaul Part 3:
maintenance of gas detecting and monitoring equipment.
AS/NZS 60079-
29.1:2008
Explosive atmospheres part 29.1: Gas detectors - Performance requirements of
detectors for flammable gases
AS/NZS 60079.0-
2011
Explosive atmospheres - Part 0: Equipment - General requirements
AS/NZS 60079.11-
2011
Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"
GG2
Gasguard 2
Time of response
T90
Time interval, with the equipment in a warmed-up condition, between the time
when an instantaneous change between clean air and the standard test gas, or
vice versa, is produced at the equipment inlet, and the time when the response
reaches a stated percentage (90%) of the stabilised signal on the standard test
gas
RTGMS
Real Time Gas Monitoring System
SIS
Safety Instrumented Functions. A SIF is composed of any combination of
detector(s), logic solver(s), and final element(s). A SIS is usually has a number
of safety functions with different SIL’s so it is best avoid describing it by a single
SIL
SIL
Safety Integrity Levels

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 9 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Term
Definition
SRS
Safety Requirement Specification - containing all the requirements of the safety
functions that have to be performed by the safety-related system. It includes
both what the functions must do and also how well they must do it. It is often a
contractual document between companies and is one of the most important
documents in the safety lifecycle process
ILAC
International Laboratory Accreditation Cooperation Mutual Recognition
Arrangement.
ILAC is the international organisation for accreditation bodies operating in
accordance with ISO/IEC 17011 and involved in the accreditation of conformity
assessment bodies including calibration laboratories (using ISO/IEC 17025),
testing laboratories (using ISO/IEC 17025), medical testing laboratories (using
ISO 15189), inspection bodies (using ISO/IEC 17020) and proficiency testing
providers using ISO/IEC 17043.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 10 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
1 SAFETY AND OTHER WARNINGS
For safety reasons, the GG2 Real Time Gas Monitoring System 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.
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:
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.
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.
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.
Installation
Correct operation and safety depend on GG2 Display 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.
Operation
As safety depends on GG2 Display functioning correctly it is highly recommended that all safety
functions of the unit be periodically tested to ensure correct operation.
1.2 Supplementary Documentation
The GG2 Detector Real Time Gas Monitoring Design, Installation and Maintenance Guide is expected
to be read in conjunction with the following documentation:
GG2B023 GG2 Display User Manual
GG2B011 GG2 Detector User Manual
GG2B032 GG2 Communication User Manual

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 11 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
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 the 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 specifications
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
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 12 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
3 DESIGN PRINCIPLES
3.1 Planning and Designing RTGMS’s
Real Time Gas Monitoring systems are typically used to perform safety-instrumented functions, i.e. by
design taking an industrial process to a safe state when specified conditions are violated and taking
action to mitigate the consequences of a hazard. Real time gas monitoring systems commonly comprise
a single or multiple gas detector input(s), a logic controller and an output. Additional equipment is
typically incorporated into a real time gas monitoring detection system, i.e. a gas monitoring telemetry
system. If a real time gas monitoring system is to be effectively used for safety-instrumented functions, it
is essential that the system as a whole achieve certain minimum standards and performance levels.
A real time gas monitoring safety management system, at the very least, should provide the following:
a. Safety requirements specification
a. Specific actions and behaviour of the gas monitoring system
b. Continuous monitoring of the mine’s atmosphere to detect flammable and toxic gases applicable
at the site being monitored, i.e. methane, carbon monoxide, carbon dioxide, and oxygen
c. Identifies the locations at which the gas content of air is to be monitored
d. Automatically detecting the values and trends
e. Automatically activating an alarm if a gas alarm level is exceeded
f. Recording the values (historian)
g. An alternative electricity supply to ensure the system continues to function if the normal electricity
supply fails
h. Continuous monitoring, using the mine’s gas monitoring system, to detect products of combustion
in the mine atmosphere
The system designer should consider the following but not limited to:
The purpose of the gas monitoring safety system and the safety function
Statutory requirements
Local government requirements
Safety Requirements specification
oThe stated safety function per sensing point should include an acceptable response time
when a proof test is required.
Detector types
oDiffusion
oAspirated
Detector Location
oAmbient operating conditions –temperature, pressure, humidity
oAir flow volume and direction
oVibration, shock and mechanical protection
oElectromagnetic Interference (EMI)
Gas types
oFlammable gases
oToxic Gases
The number of detectors; ensuring that failure or maintenance removal of an individual detector
does not compromise the safety of the area being monitored. Duplication or triplication of
detectors and control apparatus may be required for continuous monitoring and to prevent false
alarms.
Coverage Density –potential sources

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 13 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Figure 1: GG2 Example System (iMAC Communication)
3.2 Real Time Detectors as part of a safety system
Simplified Design Principle:
Why choose, purchase, install, commission, and maintain real time detectors (at significant cost)?
oTo implement a safety function such as:
If <concentration is greater/less than x%> then <take action> withing <timeframe>
<take action> might be:
Trip power
Sound alarm
Give visual indication
<timeframe> might be:
10 milliseconds
100 milliseconds
30 seconds
iMAC Fieldbus

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 14 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
4 TYPICAL FLAMMABLE AND TOXIC GASES IN COAL MINES
4.1 Methane (CH4)
Methane is a colourless, flammable, non-toxic gas that has no odour in its pure state. Methane is the
major component of natural gas and is found in varying levels in most coal deposits. It is a simple
asphyxiant due to its ability to displace oxygen from air where sufficient quantities exist. With a density
relative to air of 0.55, it is lighter and will tend to accumulate at the roof level of spaces where limited
ventilation exists.
4.2 Hydrogen Sulphide (H2S)
Hydrogen sulphide is a colourless gas that has a sweet taste and a pungent odour resembling that of
rotten eggs. Hydrogen sulphide is produced from the decay of organic materials and is a naturally
occurring seam gas in some coal and shale deposits. Hydrogen sulphide has a density of 1.19 relative to
normal air and, as such, will tend to pool and stagnate in low lying areas and poorly ventilated areas.
4.3 Carbon Monoxide (CO)
Carbon monoxide is a colourless, odourless, tasteless gas with a density relative to normal air of 0.97.
Carbon monoxide is formed during the incomplete combustion of any carbonaceous material. It is always
present in proximity to coal fires. Due to its general association with heat it is usually found in spaces
tending toward roof level even though it has a specific gravity similar to air. Carbon monoxide is both
flammable and explosive. The flammable limits in air are 12.5 to 74% with the most explosive
concentration being 29%.
4.4 Carbon Dioxide (CO2)
Carbon Dioxide is a colourless gas with a slight pungent or acrid smell and a soda water taste. It has a
density relative to normal air of 1.53 and will accumulate in low lying and unventilated areas.
4.5 Sulphur dioxide (SO2)
Sulphur dioxide is a colourless gas with a strong pungent odour that can be detected when the
concentration reaches approximately 3ppm. It is heavier than air with a density relative to air of 2.26.
Sulphur dioxide is produced by the combustion of sulphur compounds and is usually found in the vicinity
of heating in coal containing sulphur.
4.6 Nitrogen dioxide (NO2)
Nitrogen dioxide belongs to a group of gases collectively referred to as the oxides of nitrogen. Other
gases in this group include nitric oxide (NO), nitrous oxide (N2O) and nitrogen peroxide (N2O4).

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 15 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
5 REAL TIME GAS MONITORING SYSTEM SAFETY GUIDELINES
Real time gas monitoring systems are used whenever there is the possibility of a hazard to personnel or
property caused by the increase or outburst of a flammable and/or toxic gas to air ratio. Real time gas
monitoring systems are typically deployed as means of reducing the hazard by detecting the presence of
a flammable or toxic gas and issuing suitable warnings to initiate precautionary steps such as electrical
plant shutdown.
It is imperative to understand the real time gas monitoring design, i.e. the purpose, the number of
sensing points, their appropriate location, redundancy and the management of regular maintenance.
Performance capability alone cannot ensure that the use of real time gas monitoring systems will suitably
safeguard personnel or property where flammable or toxic gases may be present. To achieve the
desired level of safety relies on conversant management, a well-developed safety requirement
specification, system limitations and maintenance practices.
5.1 Risk Analysis Guidelines
Flammable and toxic gases are responsible for the generation of numerous hazards. Oxygen levels may
be depleted. A risk analysis should consider all hazards associated with gases and vapours, which
include:
i. Short-term effects
ii. Long-term effects
iii. Personnel exposure (TWA, STEL)
Computational modelling is recommended to simulate and study the complexity of a real time gas
monitoring system, i.e. modelling ventilation, specific gas densities, and planning location of electrical
plant and task areas from the outputs of the model.
System Behaviour, Safe, Unsafe and Special State Failures
The detection of failures in a real time gas monitoring system should be referenced to the Safety
Requirements Specification, and to the result of the development and initiation of trigger action response
plans detailing but not limited to:
a. A method where the fault is conveyed to the attention of the system maintainer/operator, who
initiates a repair action.
b. A method where the fault is conveyed to the attention of the system maintainer/operator to initiate
an action to achieve a safe state so that the safety function is made available within the specified
time to reinstatement of the real time gas monitoring system.
The Safety Requirements Specification and trigger action response plan should specify the acceptability
of the system unavailability when a fault is detected.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 16 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
6 DETECTOR PRINCIPLES
Gas detection systems are reliant upon the ventilation system to move the gas vapour to the sensing
element. However, it should be realised that the sensing point location can have an overall effect on the
operation of any fixed gas detection system, irrespective whether the system is safety related or not.
A real time gas monitoring safety system can be considered to consist of at least five consecutive
subsystems:
Gas propagation from source to detector
Gas propagation through detector
Sensing element delay
Detector signal processing
Safety system actuation
Each of these subsystems has an inherent delay.
Figure 2: Factors Effecting Response Times
6.1 Detector Filter Elements
GG2 detectors incorporate a passive filter element to protect the detector gas membrane from airborne
dust, dirt and moisture. All types of passive filter elements have a dangerous undetected failure mode
(e.g. blockage) and; therefore, require scheduled inspection and proof testing.
6.2 Maintenance Considerations
Accurate adjustment of the GG2 detector requires span gas for bump/challenge testing, and
calibration/adjustment purposes, which usually contains the target gas in a known concentration with a
tolerance of less than 5% relative.
Kits for routine adjustment, calibration functional checks and performance testing of single point
detectors, and portable and transportable equipment usually consist of:
Zero gas
Span gas
0.5/1.0 LPM Flow Regulator
Tubing
Calibration Mask (cup)
Magnet –for instrument adjustment

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 17 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
7 INSTRUMENTATION TIME OF RESPONSE (t90)
The intent of time of response test is to determine degradation in the sensing element or
blockages be partial or full. The critical observation is the trend over time of each detector. If the
detector response is slowing in successive observations, then the detector performance is
degrading and further inspection or intervention is required before the detector fails. One of the
most common causes of performance degradation is due to the accumulation of dust and
particles on external filters. AS/NZS2290.3:2018 is a guide to facilitate safe and efficient use of
gas detection equipment.
A detector’s response time is a critical parameter which validates its intended safety function which is the
real time monitoring of gas concentrations.
Diffusion type gas detectors are reliant on the natural equalisation of gas concentrations inside and
outside the detector, driven by the respective partial pressures of gases. This equalisation can be
impeded (to a greater or lesser degree), by the necessary filters and hydrophobic barriers protecting the
fragile sensing elements from the typically harsh mine environments. This impediment is present in all
detectors and typically, the gas detector design is verified to comply with the performance requirements
of relevant Australian Standards. (AS/NZS 60079.29.1 for flammable gases and AS/NZS 4641 for toxic
gases and oxygen).
Where the mine environment is dusty, airborne contaminants are deposited on the gas detector’s
external surfaces, including its protective filters and barriers. The gradual accumulation of dust and other
foreign matter on the protective filters and barriers can further inhibit the diffusion of gas into a detector,
degrading the two key performance criteria of accuracy and speed of response.
AS/NZS2290.3:2018 Electrical equipment for coal mines –Introduction, inspection and maintenance
Part 3: Gas detecting and monitoring equipment, prescribes the acceptance criteria for time of response
for flammable Gas Detectors being ≤30 seconds.
How critical is time of response? Is less or even greater than 30 seconds acceptable?
To determine an acceptable response time, a design risk assessment should be undertaken and
consider items as mentioned in Section 3.
Key factors being:
Ventilation speed
Location of detectors in reference to the plant or personnel
Telemetry response times
HV reticulation and electrical plant
Task areas
WARNING!
The absolute response time of a Gasguard detector should only
be undertaken by an ILAC recognised test laboratory accredited
to AS ISO/IEC 17025 and to IEC/ASNZS 60079-29-1.
The relative response time of a Gasguard detector (that is,
relative to a Gasguard detector of known response time) can be
measured as detailed in Section 8.6.

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 18 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Factors affecting the T90 Response Time Test:
Environmental –Dust and water
Physical –damage
Gas exposure –high exposure
Poisoning –chemical compounds
Temperature –exceeding temperature limits
Humidity –moisture condensing on detectors
Calibration drift
Integrity or test kit
Pressure in span gas sample/bottle
Recommendations
1. Review the mine safety management system and the Real Time Gas Monitoring System safety
requirements specification, with consideration of the following:
The purpose of the gas monitoring safety system i.e Safety function and the Safety
Requirements Specification
Statutory requirements
Local government requirements
Safety Requirements specification
Detector types
oDiffusion
oAspirated
Detector Location
oAmbient operating conditions –temperature, pressure, humidity
oAir flow volume and direction
oVibration, shock and mechanical protection
oElectromagnetic Interference (EMI)
Gas types
oFlammable gases
oToxic Gases
Telemetry response times
The number of detectors, ensuring that failure or maintenance removal of an individual
detector does not compromise the safety of the area being monitored. Duplication (or
triplication) of detectors and control apparatus may be required for continuous monitoring
and to prevent false alarms.
Coverage Density –potential leak sources
HV reticulation and electrical plant location
2. Assess this test under a risk based approach
The intent of a time of response test is to determine degradation in the sensing element or
blockages, be they partial or full. The critical observation is the trend over time of each detector. If
the detector response is slowing in successive observations, then the detector performance is
degrading and further inspection or intervention is required before the detector fails. One of the
most common causes of performance degradation is due to the accumulation of dust and
particles on external filters. AS/NZS2290.3:2018 is a guide to facilitate safe and efficient use of
gas detection.
AS/NZS2290.3:2018 extract “The objective of this Standard is to facilitate the safe, efficient and
productive use of gas detection and monitoring equipment in coal mines, by specifying
requirements and recommendations for the inspection and maintenance of such equipment.”

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 19 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
Some consideration may be given to the following during a risk analysis::
Test a sample of new detectors in-situ under the environment they are required to perform
in.
Set a baseline to which degradation can be measured
Determine a suitable ±offset to the baseline
Use this value as your t90 pass/fail reference to initiate maintenance on the detector
7.1 Detector Blockages
Figure 3: Detector Blockages
7.2 Response Time @ Different Concentrations
Figure 4: Response Time @ Different Concentrations

Ampcontrol Pty Ltd –ABN 28 000 915 542
GG2 SYSTEM DESING, INSTALLATION AND
MAINTENANCE APPLICATION GUIDE
GG2B033 Version 1 –NOVEMBER/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 20 of 45
APPROVED FOR EXTERNAL DISTRIBUTION –PROPERTY OF AMPCONTROL PTY LTD –NOT TO BE REPRODUCED IN PART
7.3 Response Time to a Set Alarm or Trip Point
Figure 5: Response Time to a Set Alarm or Trip Point
7.4 Gastrack Simulation –Ventilation/Gas Outburst Distribution
Gastrack is a simulation tool to visualise the latency in a typical telemetry system.
Figure 6: Gastrack Simulation