Gas Data GFM 436 User manual

9ENG8008 GFM436 User Manual
Exported on
02/02/2024

9ENG8008 GFM436 User Manual
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Table of Contents
1 Handheld Gas Analyser for Landfill......................................................................6
2 WARNINGS .............................................................................................................7
3 GFM436 ..................................................................................................................8
4 GFM436 General Information ...............................................................................9
4.1 Introduction ................................................................................................................................9
4.1.1 Features..................................................................................................................................................................... 9
4.2 Spares List .................................................................................................................................10
5 Safe Use of the GFM436 ......................................................................................12
5.1 Important Safety Related Points..............................................................................................12
6 GFM436 Product Specification ...........................................................................14
6.1 Introduction to the GFM436 Functions and Features .............................................................14
6.2 GFM436 Instrument Specification............................................................................................16
6.3 Specialist Functionality ............................................................................................................18
6.3.1 Lower Explosive Limit ............................................................................................................................................. 18
6.3.2 Managing Hydrocarbons Using the Hexane Channel............................................................................................ 18
6.3.3 PID Compensation Factor Prediction .................................................................................................................... 19
6.4 Third Party Approvals ...............................................................................................................20
6.4.1 ATEX, UKEX and IECEx............................................................................................................................................. 20
6.5 In the Case .................................................................................................................................21
6.6 Front Panel Control Layout ......................................................................................................23
6.7 GFM436 Connections ................................................................................................................24
6.8 Optional Extra Accessories .......................................................................................................25
7 GFM436 Operation ..............................................................................................27
7.1 Starting Up ................................................................................................................................27
7.2 Navigating the screens .............................................................................................................28
7.3 Reading the Displays.................................................................................................................29

9ENG8008 GFM436 User Manual
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7.4 View Readings ...........................................................................................................................35
7.5 Clock Display .............................................................................................................................37
7.6 Connecting the Gas Sample Pipe .............................................................................................38
8 Gas Readings .......................................................................................................41
8.1 Gas Display ................................................................................................................................41
8.2 Gas Display Two ........................................................................................................................42
9 Pressure Readings...............................................................................................44
9.1 Connecting the Gas Flow Pipe..................................................................................................44
9.2 Taking a Static Pressure (SP) Measurement............................................................................46
10 Gas Velocity Readings.........................................................................................48
10.1 Gas Velocity Measurement with Optional Vane Anemometer................................................48
11 Gas Temperature Readings ................................................................................50
11.1 Gas Temperature Measurement with Optional Temperature Probe .....................................50
11.2 DIP Meter Reading.....................................................................................................................50
12 Storing Data.........................................................................................................52
12.1 Storing Data...............................................................................................................................52
12.2 Data storage ID structure..........................................................................................................53
12.3 Sample Point Setup ..................................................................................................................57
12.4 Logging Setup ...........................................................................................................................61
12.4.1 Pump Time .............................................................................................................................................................. 63
12.4.2 Period ...................................................................................................................................................................... 63
12.4.3 Total Logs ................................................................................................................................................................ 64
12.4.4 Bat Save On ............................................................................................................................................................. 64
12.5 Logging Display .........................................................................................................................65
12.6 Logging Setup ...........................................................................................................................67
12.7 Store Menu ................................................................................................................................67
13 User Calibration ..................................................................................................68
14 Auto Turn Off .......................................................................................................75

9ENG8008 GFM436 User Manual
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15 GFM436 - Maintenance........................................................................................76
16 Appendix A – Velocity Flow Conversion Charts .................................................77
17 Appendix B – Understanding Instruments For Use In Flammable
Atmospheres .......................................................................................................78
17.1 Hazardous areas classified by zones........................................................................................78
17.2 Different types of gas ................................................................................................................78
17.3 Design and construction of intrinsically safe instruments for use in flammable
atmospheres .............................................................................................................................79
17.4 Testing and Certification ..........................................................................................................80
18 Appendix C – Vane Anemometer ........................................................................81
18.1 Operating Instructions..............................................................................................................81
18.2 Important notes ........................................................................................................................81
18.3 Streamline Measuring Head .....................................................................................................81
18.4 Response time...........................................................................................................................82
18.4.1 Response Time of electronics:................................................................................................................................ 82
18.4.2 Response Time of Vanes: ........................................................................................................................................ 82
18.4.3 Technical data – MiniAir 6 Micro............................................................................................................................. 82
18.5 Cleaning and maintenance.......................................................................................................82
18.5.1 General handling tips.............................................................................................................................................. 83
18.5.2 Vane probes............................................................................................................................................................. 83
18.5.3 Cable, extension rod, case...................................................................................................................................... 84
18.5.4 Snap Head ............................................................................................................................................................... 85
18.5.5 Checking/factory inspections................................................................................................................................. 85
19 Appendix D – Warranty Policy ............................................................................86
19.1 Conditions and exclusions........................................................................................................86
19.2 Disposal .....................................................................................................................................86
20 Appendix E – Declarations of Conformity ..........................................................87
20.1 EU DoC .......................................................................................................................................87
20.1.1 The Electromagnetic Compatibility Directive 2014/30/EU: ..................................................................................87
20.1.2 ATEX Directive 2014/34/EU: .................................................................................................................................... 88

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20.1.3 IECEx: ....................................................................................................................................................................... 88
20.2 Notified body.............................................................................................................................89
20.3 Additional information .............................................................................................................89
20.4 Signature ...................................................................................................................................90
20.5 UK DoC.......................................................................................................................................90
20.5.1 The Electromagnetic Compatibility Regulations 2016:......................................................................................... 91
20.5.2 Equipment and Protective Systems Intended for use in Potentially Explosive Atmospheres Regulations
2016:......................................................................................................................................................................... 92
20.6 Notified body.............................................................................................................................92
20.7 Additional information .............................................................................................................92
20.8 Signature ...................................................................................................................................93
21 Appendix F – ATEX, UKEX and IECEx Certificate ................................................95
22 Appendix G – Non-EX Safety Critical Information..............................................98
23 Appendix H - Three Letter Codes........................................................................99

9ENG8008 GFM436 User Manual
1 mailto:[email protected]
2 https://gasdataltd.atlassian.net/wiki/spaces/IMSM/pages/528548839/Gas+Data+Contact+Information
3 https://gasdataltd.atlassian.net/wiki/spaces/IMSM/pages/528548839/Gas+Data+Contact+Information
Handheld Gas Analyser for Landfill- 6
1 Handheld Gas Analyser for Landfill
Gas Data Ltd.
Unit D
Earlplace Business Park
Fletchamstead Highway
Coventry
CV4 9XL
[email protected]1
[phone]

9ENG8008 GFM436 User Manual
WARNINGS- 7
2 WARNINGS
The manufacturer reserves its right to update the contents of this manual, in line with the evolution of the product.
Text and pictures in the manual are not binding.
Copyright © 2023
All rights to translation, adaptation and reproduction by any process reserved in all countries. No part of this
document may be copied, reproduced or transcribed without the written consent of the manufacturer.
No part of this document may be circulated outside of the manufacturer in this form.

9ENG8008 GFM436 User Manual
GFM436- 8
3 GFM436
The GFM436 gas analyser is part of the GFM range, designed and manufactured by Gas Data Ltd.

9ENG8008 GFM436 User Manual
GFM436 General Information- 9
4 GFM436 General Information
4.1 Introduction
The Gas Data GFM436 handheld series of analysers is designed specifically for monitoring and analysing gas content
of landfill, biogas and contaminated land sites. It measures the methane, oxygen and carbon dioxide content of site
gases, gas pressure or vacuum, and gas velocity.
Operation is extremely simple, yet the readings obtained are highly accurate. The instrument uses Gas Data's
proprietary infra-red methane and carbon dioxide sensors and a combination of industry standard electrochemical
gas sensor cells. A variety of external sensors can be plugged in, e.g. vane anemometer to measure gas velocity or a
temperature probe for ambient and other temperatures.
The GFM436 series has rechargeable Nickel Metal Hydride batteries giving around eight hours use between charges.
A battery charger and mains unit is supplied with the instrument and a field replaceable battery pack is also
available as an optional extra.
4.1.1 Features
· Up to 7 gas analysis channels.
· 4 Wavelength optical infra-red analyser.
· Atmospheric pressure.
· Powerful sample pump.
· User replaceable sample filter.
· Field replaceable/rechargeable battery pack.
· Optional flow, pressure and temperature.

9ENG8008 GFM436 User Manual
GFM436 General Information- 10
4.2 Spares List
Category Description GD order code
Spares GFM internal Filters 15mm 18811
GFM external Filters 25mm 18810
GFM external Filters 50mm 18818
GFM/Click! Sample Pipe Connector (Male Metal) 18812
Chrome Plate Brass Coupling 1/8" ID Hose St.Thru 20710
GFM/Click! Sample Pipe Connector (Male plastic) 18934
GFM426 and GFM526 Sample Pipe 20726
GFM Sample Pipe 17227
GFM43x Sample Tube 17226
GFM43x/610 Flow Tube 16480
GFM426 and GFM526 External Filter Housing Assembly - Black ABS 20838
GFM Drilled Battery Cover, Black, ABS 17214
GFM Spares Kit 14265
Inlet housing 17204
Power Battery pack 16457
AC Mains Battery charger 16455

9ENG8008 GFM436 User Manual
GFM436 General Information- 11
Universal DC In-Car Multi Voltage Power Adaptor 21266
GFMxxx North America Charger Foot (Blue Bag) 22626
Accessories USB Download cable 16501
Brass Temperature Probe 16503
Leather cover 16781
GFM Vane Anemometer Probe 0.5 - 40m/s 16502
Black carry case 17111

9ENG8008 GFM436 User Manual
Safe Use of the GFM436- 12
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5 Safe Use of the GFM436
This instrument has been designed to operate in typical field environments where flammable gases may be present.
All ‘Special Conditions for Safe Use’ as detailed on the ATEX, UKEX and IECEx certificates (see the appendices) must
be adhered to.
5.1 Important Safety Related Points
The safest medium to sample a gas line with the instrument is to connect it to an isolated sample line,
accessible by a ball valve (or another suitable alternative).
Sampled gas will be discharged from the ‘sample out’ port of the instrument at a rate of approximately 500ml/
min.
Flush the instrument with clean air before sampling to prevent mixing potentially reactive mixtures of gas
within the instrument.
Verify instrument calibration before and after use to minimise the risk of falsely determining an atmosphere
as hazardous or safe.
Do not connect the instrument to gas sources at greater than +50 mbar above atmospheric pressure.
Do not operate the instrument in ambient temperatures outside the range of -10 to +40 °C (14°F to 104°F)
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The following points must be observed:-
The instrument must be recharged in the non-hazardous area.
The instrument must be checked for normal operation prior to carrying it into the hazardous area:
BEFORE entering a known hazardous zone, switch on the instrument and make sure the display is
visible and that the keys respond correctly.
BEFORE entering a known hazardous zone, check that the sample pump can be operated.
The instrument must be inspected for damage prior to use and the instrument must not be used if
the case is damaged:
BEFORE entering a known hazardous zone, check the instrument for damage. Pay particular
attention to the keyboard and aspirator.
The instrument must be carried in the leather case to avoid the risk of electrostatic discharge:
BEFORE entering a hazardous zone make sure that the instrument is securely enclosed in its leather
case.
IMPORTANT: Failure to comply with the safety warnings in this chapter can be potentially hazardous to
the user and others.

IMPORTANT: Make sure this gas will not create a hazardous zone worse than ZONE 1.
See the appendices for a full description of hazardous zones.


9ENG8008 GFM436 User Manual
Safe Use of the GFM436- 13
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Do not attempt to dismantle the instrument outside of the instructions in this manual.
Do not operate the instrument if it is damaged in any way (i.e. loose front panel, missing screws etc.).
Do not connect or remove electrical connectors on the top of the instrument in the hazardous area.
Do not use (i.e. power on) the instrument while charging.
Only charge the batteries in a safe well ventilated area using the charger supplied.
Ensure correct filter is used on the Gas In port – If any doubt please contact the manufacturer
Use only the manufacturer’s spares and accessories – See spares list.
For further information please refer to the appendices on Understanding Instruments For Use In Flammable
Atmospheres and ATEX, UKEX and IECEx Certification.
IMPORTANT: The manufacturer cannot accept any liability for loss or damage due to its usage. Satisfy
yourself that the unit is suitable for the application that you intend to use it for. If in doubt about the
suitability of this instrument for a particular application call the manufacturer for further advice.


9ENG8008 GFM436 User Manual
GFM436 Product Specification- 14
6 GFM436 Product Specification
6.1 Introduction to the GFM436 Functions and Features
The GGFM436 is an ATEX accredited hand-held gas analyser designed specifically for monitoring and analysing soil
gas parameters in greenfield and brownfield (contaminated land) sites and landfill sites.
It is lightweight, small and robustly manufactured in a weather resistant case making it suitable for use even in
challenging field applications. It measures the methane, carbon dioxide, oxygen, hydrogen sulphide, hexane and
carbon monoxide content of the gas sample. It also has internal sensors for the measurement of gas pressures (or
vacuum) and flow. External sensors can be attached for the measurement of temperature and gas velocity.

9ENG8008 GFM436 User Manual
GFM436 Product Specification- 15
Operation is extremely simple, yet the readings obtained are highly accurate. The instrument uses Gas Data's
proprietary infra-red methane and carbon dioxide sensors and a combination of industry standard sensors for the
other parameters.

The GFM436 has a rechargeable Nickel Metal Hydride battery pack giving around eight hours use between charges.
A universal input mains battery charger unit is supplied with the instrument. Additional field replaceable battery
packs and an in car 12V DC powered charger are also available as optional extras.

To help conserve battery life, the GFM436 features an auto power off facility. It will switch itself off after 15 minutes
if no keys are pressed or there is no USB communication activity. During unattended data logging, it can be set to
shut itself down after taking a sample and turn itself back on to take the next sample. The instrument will also
switch off if the battery voltage is too low for it to operate.

The GFM436 features data storage with three-layer alphanumeric labelling of sample points and unattended data
logging capability. Data is stored in non-volatile FLASH memory with a capacity of approximately 3000 data sets

9ENG8008 GFM436 User Manual
GFM436 Product Specification- 16
including the time and date it was stored and a 32-character alphanumeric label. Using Gas Data's SiteMan5
program data and labels can be transferred to and from a PC via a USB connection cable.
6.2 GFM436 Instrument Specification
General
Ex. Rating to: II 2 G Ex ib IIB T1 Gb
Ambient Temp Range -10 to 40 °C (14 °F to 104 °F) [N.B. the instrument is EX certified to
-20 °C / -4 °F, but the sensors are only calibrated to -10 °C / 14 °F]
Battery Life 8 hours typical
Battery charge time 2 to 4 hours
Aspiration Rate 300 ml/min
Storage Capacity >3000 Readings
Protection Rating IP65
Dimensions 200 x 100 x 60 mm
Weight 1kg typical

9ENG8008 GFM436 User Manual
GFM436 Product Specification- 17
GFM436 Channels
Channel Range Typical Accuracy Typical Response
Methane 0 to 100% (0.1) 0.3% @ 5%, 3.0% @ 60%,
3.0% @ 100%
20s
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0 to 100% LEL (0.1) 4% LEL 30s

Carbon Dioxide 0 to 100% (0.1) 0.3% @ 5%, 3.0% @ 40%,
3.0% @ 40%
20s

Oxygen 0 to 25% (0.1) 0.5%

20s
Atmospheric
Pressure
800 to 1200 mbar 5 mbar, 1 mbar resolution

20s
H2S 2000 ppm (10.0) 5% of fs

30s
CO 2000 ppm (1.0) 5% of fs

30s
Static Pressure -200mbar - +200mbar +/- 1 mbar

10s
Flow Range +100 to -60 l/hr +/- 0.1l/hr to +/-3l/hr

10s
Flow Resolution 0.1 l/hr 



9ENG8008 GFM436 User Manual
GFM436 Product Specification- 18
Differential
Pressure
+1250/-1250 Pa +/-3Pa to +/- 250Pa

10s
Optional Channels
Temperature -10 to 100°C +/-1.0°C 60s
Velocity 0-40m/s +/-0.51 m/s resolution 30s
Accessories
Battery charger, Carry Case, Sample Pipe, Manual, Calibration Certificate, Download Cable
Optional extras: Temperature probe, Vane Anemometer
6.3 Specialist Functionality
6.3.1 Lower Explosive Limit
The instrument calculates and displays the Lower Explosive Limit (LEL) of Methane. This function is intended for use
where methane has become mixed with air i.e. where oxygen is still present in normal atmospheric proportions
with respect to atmospheric nitrogen. This is the worst case so if the gas sample is taken from a location where the
oxygen content is depleted e.g. due to biological demand, then the LEL indication will be higher than expected.
6.3.2 Managing Hydrocarbons Using the Hexane Channel
The instrument incorporates an additional Hexane calibration of the infra-red sensor which is used to indicate,
quantify and track hydrocarbon gases that would normally make the infra-red methane calibration read excessively
high or even over-range rendering the results meaningless. With the GFM436 when and if the methane sensor shows
an over-range signal or abnormally high methane value (a good indicator that other hydrocarbons are present in
the borehole) the hexane value will remain valid and in range up to 2.000%.

9ENG8008 GFM436 User Manual
GFM436 Product Specification- 19
This response range is chosen as it allows typical concentration levels of hydrocarbon vapours that would be found
in contaminated ground due to the spillage of common liquid fuels and oils to be quantified on a standard scale as
a percentage hexane vapour equivalent. The Hexane signal is taken from the infra-red bench and processed to
another output on the instrument display in the scale 0.000 – 2.000%.
It does not need additional gas calibration as the infra-red beam is normalised using the existing methane
calibration gas. At 100% Methane concentration the Hexane reading will be typically showing 0.200 – 0.300% and
will continue to rise if there is a hydrocarbon problem present. Laboratory sampling is needed to establish a
baseline and identify the specific hydrocarbon compound but repeat tests with the GFM436 will allow trends to be
determined with great consistency.
Using this technique, the Hexane reading can also be used for an immediate indication that remedial action on the
borehole has been successful or not. Boreholes can be re-measured knowing that readings are “in scale” by
referencing the original readings taken. No more waiting for samples to come back from the lab!
Boreholes across a site can be compared and peak readings established to indicate those of significant interest,
worst case and negligible etc.
6.3.3 PID Compensation Factor Prediction
The PID (Photo Ionisation Detector) is the instrument widely accepted by the industry to quantify other
hydrocarbon gases present in ground boreholes. It is a good choice of instrument as it is highly sensitive to a broad
range of hydrocarbon gases and it does not directly detect methane. It uses a UV light source to ionise hydrocarbon
gases in its sample cell so that they can be quantified using an electronic charge amplifier. However, even small
quantities of methane present in a borehole can absorb the UV light thus quenching the ionisation and de-
sensitising the instruments response leading to under measurement or complete non-detection of any
hydrocarbon gases present.
The built in PID Compensation factor in the GFM436 is a figure derived from extensive testing of the non-linear
characteristics of this phenomenon and is displayed on the GFM instrument as a number between 1 and 10. This is

9ENG8008 GFM436 User Manual
GFM436 Product Specification- 20
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used to multiply the PID reading to give an accurate total hydrocarbon value in the borehole. This figure is accurate
for the Ionscience Ltd Phocheck range of PIDs up to a value of 10 which occurs at approximately 9% methane in the
borehole.
This characteristic varies between PID manufacturers. For example, typically only 5 – 6% of methane will diminish
the PID response of a RAE Systems unit to only one tenth of the correct value thus needing a PID compensation
factor of 10. Instrument characteristics when subjected to high levels of methane do differ considerably (see chart
of typical responses below).
6.4 Third Party Approvals
6.4.1 ATEX, UKEX and IECEx
This instrument is ATEX, UKEX and IECEx Certified under normal operation.
ATEX, UKEX and IECEx accreditation is void under the following circumstance:
If the instrument is removed from its leather case
If the instrument is charging or plugged into a computer i.e. not under normal operation