GMI Oxygas P-500 Instruction Manual

Oxygas P-500
User Handbook

OXYGAS P-500 USER HANDBOOK
Issue 2
11/06/13
Part Number: 42645
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i
COPYRIGHT
This User Handbook is copyright of Gas Measurement Instruments Ltd (GMI)
and the information contained within, is for use only with the Oxygas P-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 Oxygas P-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.

OXYGAS P-500 USER HANDBOOK
ii
SAFETY
• The instrument must be regularly serviced and calibrated by fully
trained personnel in a safe area.
•Batteries: Alkaline batteries or *Rechargeable battery pack must be
exchanged (*and recharged) in a safe area and fitted correctly
before use. Never use damaged batteries or expose to extreme heat.
See Section 4 : OPERATOR MAINTENANCE.
• 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.
• Gas can be dangerous and care should always be taken in its use.
• Oxygas P-500 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 in the rechargeable pack contain considerable energy and care
should be taken in their handling and disposal. Battery packs 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.
The instrument contains electrochemical sensors with a life of 2 years. Under
conditions of prolonged storage the sensors should be removed. The sensor
contains potentially corrosive liquid and care should be taken when handling
or disposing of the sensor, particularly when a leak is suspected.

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DECLARATION OF CONFORMITY
Refer to current
Declaration of Conformit
y
document Part No. 4290
7
(supplied with product)

OXYGAS P-500 USER HANDBOOK
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REVISION RECORD
Date Issue Description Of Change
29/07/04 1 New Handbook
11/06/13 2 Revised to include effect
of CN 6257.

OXYGAS P-500 USER HANDBOOK
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vii
CONTENTS
COPYRIGHT ................................................................... i
LIABILITY ....................................................................... i
MODIFICATIONNOTICES ................................................ i
SOFTWARE ................................................................... i
DISPOSALADVICE ........................................................ i
SAFETY .........................................................................ii
AREASOFUSE ............................................................. ii
STORAGE,HANDLINGANDTRANSIT ..........................ii
DECLARATIONOFCONFORMITY.................iii
REVISIONRECORD .......................................v
INTRODUCTION ............................................. 1
Overview...................................................................... 2
Combustible Gas Indicator - Leak Detection ............. 2
Purging ....................................................................... 4
GENERALINFORMATION ........................... 13
Ranges of Operation .................................................. 13
LEL, 0 to 100%......................................................... 13

OXYGAS P-500 USER HANDBOOK
viii
Volume Gas, 0 to 100 % .......................................... 14
Oxygen, 0 – 25% ..................................................... 14
PPMFlammable 0– 1000 ppm.................................. 15
Construction ............................................................... 15
Batteries...................................................................... 16
Disposable Alkaline (LR20) Dry Cell Batteries......... 16
Rechargeable Battery Pack ..................................... 16
Filters .......................................................................... 17
Liquid Crystal Display (LCD) ...................................... 17
Before Use Checks .................................................... 17
OPERATINGINSTRUCTIONS ...................... 19
Modes of Operation.................................................... 19
Switching On ........................................................... 20
Calibration Date Features ........................................ 21
Switching Off the Instrument Pump......................... 21
Switching On in Purge Mode ................................... 22
ChangingRange....................................................... 22
Zeroingthe PPM Range ........................................... 23
Switching Off........................................................... 23
Summary of Button Operation ................................. 24
Operator Messages / Fault Flags............................... 24
OPERATORMAINTENANCE ....................... 27
Rechargeable Battery Pack........................................ 27

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CONTENTS
Standard Charger..................................................... 27
Flatbed Charger ....................................................... 28
Smart Charger.......................................................... 28
Replacing the Battery Pack...................................... 29
Recharging the Battery Pack ................................... 30
ReplacingAlkaline (LR20) Dry Cell Batteries ............. 30
FilterReplacement ...................................................... 32
.................................................................................... 33
CALIBRATION .............................................. 35
Calibration Validity....................................................... 35
ACCESSORIES ........................................... 37
ADDITIONALINFORMATION........................ 41
Training ....................................................................... 41
World Wide Web ......................................................... 41
TYPICALOPERATINGPARAMETERS .......A-1
Size ........................................................................ A-2
Weight .................................................................... A-2
Operating Temperature .......................................... A-2
Humidity .................................................................. A-2
Construction........................................................... A-2

OXYGAS P-500 USER HANDBOOK
x
Display.................................................................... A-2
SamplingSystem.................................................... A-2
Response Time (O2) .............................................. A-2
Power Source........................................................ A-3
FIELDCALIBRATION ..................................B-1
Selectable Ranges in FCM........................................ B-3
EnteringFCM............................................................. B-3
Zeroing the Instrument ............................................. B-4
Field Calibration Procedure....................................... B-5
QuittingFCM.............................................................. B-9
Quit And Save Changes ........................................ B-9
Quit Without Saving Changes ................................ B-9
OPERATINGINSTRUCTIONS .....................C-1
English..................................................................... C-2
Deutsch (German) .................................................. C-6
L'italiano (Italian)................................................... C-10
Svensk (Swedish)................................................ C-14
Dansk (Danish)...................................................... C-18
Nederlands (Dutch) ............................................. C-22
Greek..................................................................... C-26
INDEX ............................................................. I

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INTRODUCTION
The Oxygas P-500 is a two button instrument designed to
measure Parts Per Million, Lower Explosive Level, Volume
flammablegasandOxygenfor (CGI)leakdetectionandpurge
operations.Theinstrument is designedtothe lateststandards
and is certified for use in Hazardous Areas.
The OxygasP-500 contains the following ranges:
• LEL, 0 to 100%
• Volume gas, 0 to 100%
• PPMFlammable, 0 to 1000ppm
• Oxygen,0 to 25%
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OXYGAS P-500 USER HANDBOOK
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Overview
This chapter provides a brief overview of the principles of
operationof the instrument in its twomodes of operation.
1) CombustibleGas Indicator - LeakDetection
2) Purging
Thisis notintended as operating instruction inthe application
offinding leaks,monitoring atmospheresor practical purging
operations.In allcases, youshould followyour companyand
applicationspecific training.
Combustible Gas Indicator - Leak Detection
When there is a fire or explosion, there are usually three
contributors,as indicated in the following diagram, i.e. Fuel,
Oxygen orAir, and an Ignition Source.
Figure 1.2 Contributors to Fire / Explosion

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In some applications, all three sources are available,
e.g.a boiler burner.
In other applications, where gas may be liable to escape or
be present, ignition sources are controlled,
e.g.hazardous or zonedareas.
Inapplications, such as purging, the Air orOxygen source is
controlledor excluded.
In normal operation, where air is not excluded apart from
displacement by the fuel itself, fuel and air can mix causing
potentiallyexplosive mixtures.
If insufficient fuel is present, e.g. the mixture is too “lean” to
cause ignition, then the atmosphere is “safe”.
Theminimumamountoffuel in airthatcancausean explosion
iscalled theLower Explosiveor FlammableLimit -LEL /LFL.
If the mixture has too much fuel, and hence insufficient air,
then again combustion cannot occur. The maximum fuel in
air ratio, where combustion can occur, is called the Upper
Explosive or Flammable Limit - UEL / UFL.
Thesefigures assumenormal atmospheres -gas inair -21%
Oxygenin 79% Nitrogen.If eitherthe 02or the N2ratio varies
significantly,then differentconditionsapply to the flammable
limitsand the instrument application.
The normal measurement for gas in air atmospheres is
% LEL.
This measurement is not used in inert atmospheres where
the % Gas or % Oxygen measurement must be used.
INTRODUCTION

OXYGAS P-500 USER HANDBOOK
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Figure 1.3 Flammability
TheOxygas P-500 uses a catalytic sensorto measure LEL,
which requires air to be present, and a thermal conductivity
sensor to measure the % Volume range.
Purging
The opening of a pipeline or vessel causes a mixing of
flammableproducts,such asgas withair, creating potentially
flammablemixtures.
It may not be possible to ensure that all sources of ignition
areremoved, hence thereis a needto avoid theformation of
flammablemixtures.
Two types of purging are generally used:
• Direct Purging - Displacement of fuel by air, or vice
versa.
• Indirect Purging - Displacement of fuel by inert gas
followedby displacement by air, orvIce versa.
Indirectpurgingisthe most commonsinceitavoids flammable
mixturesbeing created.

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Figure 1.4 Principle of Purging
Whenthepipehas been opentoatmosphere for maintenance
orwhen first being put into service, there is arequirement to
introduce flammable gas into the pipe in a controlled way to
avoid large flammable mixtures being created and to avoid
airbeing introduced into thenetwork.
Thisis doneby avoidingair and fuel mixing byintroducing an
inert or purge gas into the system so that air and fuel don’t
meet.This gas is normally Nitrogen or a mixture of Nitrogen
andCarbon Dioxide.
INTRODUCTION

OXYGAS P-500 USER HANDBOOK
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The following diagram illustrates a typical direct purging
operation and is not intended to demonstrate the purge
technique,but illustrate theeffect on the instrument reading.
Figure 1.5 Direct Purging - Commissioning
Commissioning
In the direct purge mode for commissioning, the pipe would
contain air and the pipe would be purged with Natural Gas.
TheOxygas is zeroed inair and would be switched on in the
purge mode. In commissioning the pipe would typically be
purgedto95%NaturalGas.This would beanormaloperation,
however, ininstruments calibrated in Methane you mayonly
be able to attain 85-90% reading, depending upon the
composition of the gas and the accuracy of calibration. The
NaturalGas may onlycontain 90%or lessofMethane, hence
thecalibration gasand the measured gas shouldbe asclose
together as possible in composition for purging or an
allowancemade for the difference.

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De-commissioning
Inpurgingdown toair thetypicalfigure wouldbe 2% Methane
or around 40% LEL to end the purge.
In the Purge mode only the % Gas and the 02 ranges are
availableandnormallythe% Volrangecanbe used.Areading
can be taken from the 02 range for confirmation but care
should be taken that the pressure applied to the cell is the
same or similar to the zero point, ie atmospheric pressure.
The pipe is being pressurised from atmospheric hence by
inference the pressure will change. The 02 cell can be
pressure transient sensitive, so care should be taken to
ensure that the pressure is maintained the same by means
of suitable valves or flow orifices and time allowed for the
transient effect to be minimised before a reading is taken.
Direct Purging
Although it is normal to use the Purge mode of the Oxygas
for purging, in direct purging where there is no inert
atmosphere in the pipe the instrument will operate in the
Measuremode.
Figure 1.6 Direct Purging - De-commissioning
INTRODUCTION

OXYGAS P-500 USER HANDBOOK
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When commissioning, the instrument will start in the LEL
range and autorange up automatically to % Gas when the
LELreachesaround 110%or the %Gas is greater than about
5.5%. Thus above these values of gas in air the instrument
willbe in the%Gas range and the reading increase upto the
final purge reading of >95% gas (85 - 95% depending on
calibration).
In direct purging to air the instrument in the measure mode
willstartoffin %Gas andreduce the reading in the gas range
until it autoranges back to LEL at around 4.5% CH4 in air or
99% LEL.
In the measure mode the LEL and % Vol ranges have
autotracking which forces the LEL and % Gas signals to be
thesame.
Inthe Purge mode the instrumentwill only have % O2and %
Gasranges and autotracking is disabled.
With2% CH4 or40% LEL the Oxygen content of the sample
isonly reduced by around 0.4% O2 which may be difficultto
measureaccurately.
THE MEASURE MODE SHOULD NOT BE USED FOR
INDIRECT PURGING.