Gas Measurement Instruments Gascoseeker 2-500 Instruction Manual

Gascoseeker 2-500
User Handbook

GASCOSEEKER 2-500 USER HANDBOOK
2
Issue 2
22/01/15
Part Number: 42476
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INSTRUMENT SERIAL NUMBER
DATE OF ISSUE
ISSUED TO
RECORD OF INSPECTIONS
DATE WORKSHOP INSPECTED
BY
CHECKED
BY

i
COPYRIGHT
This User Handbook is copyright of Gas Measurement Instruments Ltd (GMI) and
the information contained within, is for use only with the Gascoseeker 2-500
instrument. Reproduction, in whole or in part, including utilisation in machines
capable of reproduction or retrieval without written permission of Gas Measurement
Instruments Ltd is prohibited. Reverse engineering is not permitted.
LIABILITY
Every care has been taken in the preparation of this document, but GMI Ltd do not
accept any responsibility for errors or omissions and their consequences. Information
in this document is subject to change without notice. This document does not constitute
a specification or basis for a contract. Your statutory rights under law are not affected.
MODIFICATION NOTICES
GMI aim to notify customers of relevant changes in the product operation and maintain
this manual up to date. In view of the policy of continuous product improvement
there may be operational differences between the latest product and this manual.
This Handbook is an important part of the Gascoseeker 2-500 product. Please note
the following points:
• It should be kept with the instrument for the life of the product.
• Amendments should be attached.
• This Handbook should be passed on to any subsequent owner/user of the
instrument.
• Although every care is taken in the preparation of this Handbook it does not
constitute a specification for the instrument.
SOFTWARE
Software supplied on EPROM or similar device for use in a particular product, may
only be used in that product and may not be copied without the written permission of
Gas Measurement Instruments Ltd. Reproduction or disassembly of such embodied
programmes or algorithms is prohibited. Ownership of such software is not
transferable and GMI Ltd does not warrant that the operation of the software will be
error free or that the software will meet the customer’s requirements.
DISPOSAL ADVICE
When no longer in use, dispose of the instrument carefully and with respect for the
environment. GMI will dispose of the instrument without charge if returned to the
factory.

GASCOSEEKER 2-500 USER HANDBOOK
ii
SAFETY
• The instrument must be regularly serviced and calibrated by fully trained
personnel in a safe area.
•Batteries: Alkaline batteries must be exchanged in a safe area and fitted
correctly before use. Never use damaged batteries or expose to extreme heat.
• Only GMI replacement parts should be used.
• If the instrument detects gas, follow your own organisation’s procedures and
operational guidelines.
• The combustion chamber is a flameproof assembly and must not be opened
in the presence of a flammable atmosphere.
• Gasurveyor 500 series instruments are certified as EEx iad IIC T4
(-20oC<Tamb <50oC). BAS01ATEX2292 II 2 G.
UL Class 1 Groups A, B, C and D.
• This equipment is designed and manufactured to protect against other
hazards as defined in paragraph 1.2.7 of Annex II of the ATEX Directive
94/9/EC
Any right of claim relating to product liability or consequential damage to any third
party against GMI is removed if the warnings are not observed.
AREAS OF USE
Exposure to certain chemicals can result in a loss of sensitivity of the flammable
sensor. Where such environments are known or suspected it is recommended that
more frequent response checks are carried out. The chemical compounds that can
cause loss of sensitivity include Silicones, Lead, Halogens and Sulphur. Do not
use instrument in potentially hazardous atmospheres containing greater than 21%
Oxygen. The enclosure material is polypropylene and must not be exposed to
environments which are liable to result in mechanical or thermal degradation or to
damage caused by contact with aggressive substances. Additional protection may
be required in environments where the instrument enclosure is liable to damage.
STORAGE, HANDLING AND TRANSIT
The batteries should be removed if the instrument is stored for longer than 3 months.
The instrument is designed to handle harsh environments. The sensing elements are
sealed to IP54 and the rest of the instrument to IP64. If not subject to misuse or
malicious damage, the instrument will provide many years of reliable service.

iii
REVISION RECORD
Date Pages Description Of Change
Issue 1 All New User Handbook
26/08/03
Issue 2 36 Revised to include effect
22/01/15 of CN 6445

GASCOSEEKER 2-500 USER HANDBOOK
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v
GASCOSEEKER 2-500 USER HANDBOOK
CONTENTS
COPYRIGHT ................................................................. i
LIABILITY ...................................................................... i
MODIFICATION NOTICES ........................................... i
SOFTWARE .................................................................. i
DISPOSAL ADVICE ...................................................... i
SAFETY ........................................................................ ii
AREAS OF USE ........................................................... ii
STORAGE, HANDLING AND TRANSIT ...................... ii
REVISION RECORD ..................................... iii
GENERAL ..................................................... 1
% LEL ........................................................................... 2
% Volume Gas .............................................................. 2
Operation ...................................................................... 3
CONSTRUCTION ......................................... 4

GASCOSEEKER 2-500 USER HANDBOOK
vi
RANGES OF OPERATION ........................... 5
% LEL Range ............................................................. 5
% Gas Range ............................................................. 5
LEL Range Display .................................................... 6
SENSOR LIFE ............................................... 8
SPECIFICATION ........................................... 9
OPERATING PROCEDURE ....................... 10
CALIBRATION ............................................ 11
BEFORE USE ............................................. 12
MEASURE MODE ....................................... 13
1. Switch ON .............................................................. 13
2. Ready For Use ...................................................... 15
3. Sample Start .......................................................... 15
4. Sample Finish ........................................................ 16
5. Switch Off ............................................................... 17

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GASCOSEEKER 2-500 USER HANDBOOK
ZERO MODE ............................................... 19
OPERATOR MESSAGES ........................... 22
SAMPLE ................................................................... 22
OFF .......................................................................... 22
SAMPLE FAULT ...................................................... 22
ZERO FAULT ........................................................... 22
BAT ‘Flashing’ ......................................................... 22
BAT FAULT .............................................................. 22
ZERO ....................................................................... 22
PROBE ........................................................ 23
SAMPLE LINE ............................................. 29
LEL / GAS MEASUREMENTS .................... 30
Relationship of LEL and % Methane in Air ................ 30
% LEL (Lower Explosive Limit) ................................ 30
% UEL (Upper Explosive Limit) ............................... 30
% GAS ...................................................................... 30

GASCOSEEKER 2-500 USER HANDBOOK
viii
BATTERY LIFE ........................................... 32
Battery Safety Code ................................................... 34
Battery Replacement ................................... 36
ASPIRATOR BULB ..................................... 40
Carrying Straps ........................................... 43
WAISTBAND HARNESS ............................. 46
INSTRUMENT COTTON FILTER ................ 47
FAULT FINDING ......................................... 49
Fault Finding ............................................................... 52
INSTRUMENT WILL NOT SWITCH ON ................. 52
INSTRUMENT WILL NOT SWITCH OFF ................ 54
BAT FLAG OPERATES AFTER SHORT TIME ...... 55
BATTERIES DO NOT GIVE LONG USE ................ 56
BAR GRAPH ON BATTERY TEST DOES NOT
INDICATE 100% AFTER FITTING NEW BATTERIES
.................................................................................. 58

ix
GASCOSEEKER 2-500 USER HANDBOOK
SAMPLE FAULT KEEPS OPERATING .................. 59
ZERO FAULT FLAG OPERATES ........................... 61
CHECK ZERO FLAG OPERATES .......................... 63
BACKGROUND ILLUMINATION DOES NOT
OPERATE ................................................................ 64
INSTRUMENT SWITCHES ON AND IMMEDIATELY
SWITCHES OFF ...................................................... 65
INSTRUMENT STARTS CORRECTLY BUT
SWITCHES OFF WHEN PUMP OPERATED ......... 67
INSTRUMENT DOES NOT OPERATE ON DEPOT
CHECKER ................................................................ 68
GAS RESPONSE IS SLOW .................................... 70
INSTRUMENT DOES NOT CHANGE RANGE ....... 71
NO NUMBERS ON DIGITAL DISPLAY ................... 73
INDEX ............................................................ I

GASCOSEEKER 2-500 USER HANDBOOK
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1
GASCOSEEKER 2-500 USER HANDBOOK
GENERAL
The G.M.I. Gascoseeker 2-500 has been designed as a
replacement for the successful Gascoseeker Mk 2
instrument for the measurement of % LEL and % Volume
Gas.
This handbook describes the operation and user
maintenance of the instrument.
The instrument has two basic measuring ranges.
• % LEL
• % VOLUME GAS

GASCOSEEKER 2-500 USER HANDBOOK
2
% LEL
The % L.E.L. (Lower Explosive Limit) range indicates the
explosibility of the flammable gases in the sample. In the
case of METHANE (NATURAL GAS) 100% L.E.L.
represents 5% by volume Methane in air. On this range
the operating principle is a catalyst reaction and the
instrument measures the heat developed by the
combustion of the flammable portion of the atmosphere
under test.
% Volume Gas
The % Volume Gas range indicates the total Volume of a
specific gas, usually METHANE (NATURAL GAS) present
with respect to air and is scaled over the complete range
0 - 100% Volume Gas. On this range the operating principle
of the detection system is thermal conductivity.

3
GASCOSEEKER 2-500 USER HANDBOOK
Operation
A sample of the atmosphere to be measured is drawn
through the instrument by means of a pump via a filter into
the analysing chamber. The analysing chamber contains
the detection elements which monitor the gas.
Range selection is automatic.
The total system is controlled by a microprocessor which
maintains the necessary voltage conditions on the sensing
elements, controls the pump and range selection and
displays the result on a solid state analogue and digital
display.
The microprocessor carries out some housekeeping and
status management functions for the instrument and the
instrument status is also shown on the display as is the
range selected. The display is back illuminated when used
in low ambient light conditions.
The total instrument is housed in a tough impact resistant
moulded case and is powered by size D LR20 alkaline
cells to give up to 15 hours continuous operation.

GASCOSEEKER 2-500 USER HANDBOOK
4
CONSTRUCTION
The instrument is housed in a tough impact resistant
moulded case.
The case material is carbon filled polycarbonate to reduce
static risk and remove interference from radio or other
equipment.
The top surface of the instrument is covered with stainless
steel escutcheons which are marked with the necessary
basic operating instructions.
These plates provide additional impact resistance and
provide tough wear surfaces for everyday use.
Protection for the display is by toughened glass to prevent
impact damage and the display itself is mounted on a shock
absorbing mounting to prevent damage.
The instrument is sealed against dust and water ingress
to IP54 and the use of plastic mouldings and stainless
steel fastenings provide high corrosion resistance.
Additional markings and labelling are moulded into the case
as necessary.
A detachable carrying strap is provided which can be varied
in length and used as a neck sling or hand carrying handle.
Instrument operation is by sealed push-buttons on the
instrument top plate.
The instrument is ATEX certified without any additional
outer case.

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GASCOSEEKER 2-500 USER HANDBOOK
RANGES OF OPERATION
% LEL Range
On the % LEL range, the instrument shows the flammable
gas concentration up to 100% LEL which for METHANE
(NATURAL GAS) represents 5% Volume Methane in Air.
The instrument calibration is shown on the instrument label
i.e. METHANE
%
SAMPLE
10080
60
40200
LEL Range Display
% Gas Range
On the % Gas range, the instruments are calibrated for
use in METHANE and will give inaccurate results if used
in other mixtures. In addition the instruments are calibrated
for METHANE (NATURAL GAS) in Air mixtures and should
only be used for such mixtures unless specially calibrated.
The instrument calibration is shown on the instrument label
i.e. METHANE
On the % GAS range the instrument range is displayed in
the top right hand corner of the L.C.D. as GAS.

GASCOSEEKER 2-500 USER HANDBOOK
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From 0-10% GAS the digital display shows a decimal point
and resolves the digital display to 0.5% GAS.
From 10% - 100% GAS the digital display shows a decimal
point and resolves the signal to 1% GAS.
The analogue bar graph follows in 4% steps.
%
SAMPLE
10080
60
40200
Gas Range Display
LEL Range Display
On the % LEL range the instrument range is displayed in
the top right hand corner of the L.C.D. and the digital display
will show 0-100% LEL.
From 0-10% LEL the digital display shows a decimal point
and resolves the digital display to 0.5% LEL.
From 10% - 100% LEL the digital display shows a decimal
point and resolves the signal to 1% LEL.
The analogue bar graph follows in 4% steps.

7
GASCOSEEKER 2-500 USER HANDBOOK
%
SAMPLE
10080
60
40200
Analogue Bar Graph Status Flags
Digital Display Range Indicator
Digital Display with Instrument Measuring LEL Range
The LIQUID CRYSTAL DISPLAY (LCD) is protected by a
toughened glass cover and is weatherproof.
Backlighting is provided automatically to enable the display
to be seen under low ambient light conditions.
%
V
SAMPLE STORE
ZERO
FAULT
CHECK
BAT
10000PPM8000
6000
400020000
Digital Display with All Segments Activated

GASCOSEEKER 2-500 USER HANDBOOK
8
SENSOR LIFE
The sensors in the Gascoseeker 2-500 are manufactured
to give improved stability and longer life and will operate
many thousands of times with no effect on sensitivity or
zero. Exposure to high concentrations of gas will not
damage the elements.
The sensors are protected from water and dust damage
by membrane and cotton filters.
Provided the instrument is correctly maintained and
serviced, the sensors are guaranteed for 1 year in normal
operation against the effects of zero drift and calibration
deterioration within the instrument calibration span.