TROLEXX TX6373 Toxic Gas Sensor Transmitter Instruction Manual
- June 13, 2024
- TROLEXX
Table of Contents
- TX6373 Toxic Gas Sensor Transmitter
- PRINCIPAL OPERATING FEATURES
- APPLICATION
- DIMENSIONS
- TECHNICAL DETAILS
- INSTALLATION
- CONNECTIONS
- CONTROLS AND INDICATORS
- CALIBRATION
- MAINTENANCE
- APPROVALS AND CERTIFICATION
- FUNCTIONAL SAFETY
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
TX6373
TOXIC GAS SENSOR/TRANSMITTER
TX6373 Toxic Gas Sensor Transmitter
INSTALLATION & **OPERATING DATA**
| | | | |
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| |
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ISSUE N 06/15
PETROCHEMICAL PROCESSING
MINING & TUNNELLING
OFFSHORE PLATFORMS
MANUFACTURING & PROCESS PLANTS
STORAGE AREAS & WAREHOUSING
WATER MANAGEMENT & SEWAGE TREATMENT
POWER GENERATION GAS STORAGE & DISTRIBUTION TELECOMMS
PRINCIPAL OPERATING FEATURES
Stationary gas sensors for the detection of a wide range of toxic gases.
Suitable for use in SIL 1 and SIL 2 applications, in accordance with any
conditions or restrictions.
High accuracy electrochemical sensing elements.
Pre-calibrated plug-in gas sensing module with a standardised output signal
for convenient replacement and servicing.
Calibration available for a wide range of toxic gases.
Convenient push button calibration of ZERO and SPAN.
Signal fix during calibration to prevent false alarms – 4 wire systems only
Output signal versions:- 4 to 20 mA, 0.4 to 2 V & 5 to 15 Hz
Anti-static polycarbonate/ABS housing.
Intrinsically safe for use in Group I and Group II hazardous areas.
Optional format with remote mounted gas sensing module in robust metal
housing.
APPLICATION
Fixed gas monitoring for point-source hazards and perimeter protection in
arduous duty and exposed locations.
Safety protection for toxic gas risk occurring in hazardous areas and general
industrial applications.
Petrochemical processing.
Mining and tunnelling.
Offshore platforms.
Manufacturing and process plants.
Storage areas and warehousing.
Water management and sewage treatment.
Power generation.
Gas storage and distribution.
Telecommunications.
A choice of output signals for direct interfacing with most standard
industrial monitoring systems.
A range of primary instrumentation and monitoring modules is available from
Trolex to which the sensors can be directly connected to provide a flexible
choice of display and control functions.
TRIP AMPLIFIER
for use with analogue output sensors.
CONFIGURABLE SENSOR CONTROLLER
for monitoring up to 8 analogue output sensors.
COMMANDER DISTRIBUTED I/O SYSTEM
for large scale general plant monitoring systems and the mining and tunnelling
industries.
DIMENSIONS
3.1 TX6373 Toxic Gas Sensor/Transmitter
3.2 TX6373.84 Toxic Gas Sensor/Transmitter with Remote Gas Sensing Module
ALL DIMENSIONS IN MM
TECHNICAL DETAILS
4.1 Specification
Ambient Temperature Limits: | –10°C to +50°C |
---|---|
Storage Temperature Limits: | –20°C to +60°C |
Ambient Pressure Limits: | Atmospheric ± 10% |
Humidity: | 90% RH non-condensing |
Protection Classification: | Dust and waterproof to IP66. Gas inlet port to |
IP54
Housing Material:| Anti-static polycarbonate/ABS
Nett Weight:| 450 g
Cable Entries:| M20 x 1.5
Electrical Connections:| 4 mm Barrier/clamp terminals
Information Display:| Graphic LCD
Impact Limits:| 20 joules (Housing)
Calibration:| Digitally controlled ZERO and SPAN. Push button setting
Signal Fix:| The transmitted output signal of the sensor is FIXED at 00.0
during calibration to prevent false alarms from being initiated
METHANE CATALYTIC COMBUSTION
ELECTROCHEMICAL
SENSOR| SENSING
RANGE| LINEARITY| DRIFT| REPEATABILITY| RESPONSE
TIME T63%| OPERATING
**LIFE*| ORDER
REF**
---|---|---|---|---|---|---|---
Carbon Monoxide| 0 to 50 ppm
0 to 250 ppm 0 to 500 ppm| ±2% FS| 2% month| ±2%| 9 secs| >2 years|
(250.50)
(250.250)
(250.500)
Hydrogen Sulphide| 0 to 50 ppm| ±2%| 2% month| ±2%| 14 secs| >2 years| -251
Sulphur Dioxide| 0 to 20 ppm| ±2%| 2% month| ±2%| 7 secs| >2 years| -252
Nitrogen Dioxide| 0 to 20 ppm| ±2%| 2% month| ±2%| 15 secs| >2 years| -254
Chlorine| 0 to 10 ppm| ±2%| 2% month| ±2%| 37 secs| >2 years| -255
Oxygen| 0 to 25%| ±5%| 10% year| ±2%| 5 secs| >1 year| -257
Nitric Oxide| 0 to 100 ppm| ±5%| 2% month| ±2%| 9 secs| >2 years| -259
Hydrogen| 0 to 1000 ppm| ±1%| 2% month| ±2%| 13 secs| >2 years| -261
*IN CLEAN AIR
4.2 Electrical Details
TX6373.01 GROUP I APPLICATIONS (12 V dc)
Output: | 0.4 to 2 V dc |
---|---|
Min Load | 10 k ohms |
Supply | 6.5 to 16.5 V dc |
Max Current | <10 mA |
Output: | 4 to 20 mA |
---|---|
Max Load | 275 ohms @ 12 V |
Supply | 6.5 to 16.5 V dc |
Max Current | 24 mA |
Output: | 5 to 15 Hz |
---|---|
Max Load | Opto isolated. 2 mA max |
Supply | 6.5 to 16.5 V dc |
Max Current | <20 mA |
TX6373.02 GROUP II APPLICATIONS (24 V dc)
When used in conjunction with safety barriers. (Section 6)
Refer to Section 6
Output: | 4 to 20 mA |
---|---|
Max Load | 875 ohms @ 24 V dc |
Supply | 6.5 to 30 V dc |
Max Current | 24 mA |
TX6373.03 GENERAL PURPOSE APPLICATIONS (24 V dc)
NOT SUITABLE FOR USE IN CLASSIFIED HAZARDOUS AREAS
Output: | 4 to 20 mA |
---|---|
Max Load | 875 ohms @ 24 V dc |
Supply | 6.5 to 30 V dc |
Nominal Current | 24 mA |
INSTALLATION
5.1 Conformity Check
(Refer to Test Certificate provided with the sensor).
Does the output signal of the sensor concur with the input requirement of the
monitoring equipment being used?
Is the correct supply voltage available for the sensor?
Is the type of gas and its anticipated maximum level of concentration, within
the operating parameters of the sensor?
Is the temperature variation range, at the installation, within the stated
temperature range of the sensor?
Is the hazardous area classification correct?
If the hazard is Group II – are the correct safety barriers fitted?
STANDARD OPTIONS AVAILABLE
TX6373.01 | TOXIC GAS SENSOR/ TRANSMITTER | GROUP I |
---|---|---|
TX6373.02 | TOXIC GAS SENSOR/ TRANSMITTER | GROUP II |
TX6373.03 | TOXIC GAS SENSOR/ TRANSMITTER | GENERAL |
PURPOSE
TX6373.84.01| TOXIC GAS SENSOR/ TRANSMITTER with Remote Gas Sensing Module|
GROUP I
---|---|---
TX6373.84.02| TOXIC GAS SENSOR/ TRANSMITTER with Remote Gas Sensing Module|
GROUP II
TX6373.84.03| TOXIC GAS SENSOR/ TRANSMITTER with Remote Gas Sensing Module|
GENERAL PURPOSE
TYPE OF GAS Refer to Section 4.2
OUTPUT SIGNAL| 0.4 to 2 V
4 to 20 mA
5 to 15 Hz output| (11)
(12)
(13)
---|---|---
5.2 Location
Each installation needs to be considered in its own right, with reference
to safety authorities and in compliance with mandatory local safety
regulations. The sensor must be operated in accordance with the Installation
and Operating Data to maintain safety, reliability and to preserve Intrinsic
Safety integrity where applicable.
It is important that sensors are located in positions determined in
consultation with those who have specialised knowledge of the plant or
installation and of the principles of gas dispersion. Reference should also be
made to those responsible for the engineering layout and topology of the plant
as they will be most familiar with the nature of the potential dangers and the
most likely sources of gas release.
It is also important to recognise that the characteristics of the gas source
can be influenced by many factors; including the relative density or buoyancy
of the gas, the pressure at the point of release, the ambient temperature and
the ventilation of the site.
Sensor coverage cannot be simply expressed in terms of ‘number per unit area’.
Sensors need to be sited where they are capable of monitoring those parts of a
plant where gas may accumulate or when a source of gas release is expected to
occur. This way the earliest possible warning of a gas release can be given to
initiate shutdown functions, alarm functions or safe evacuation of the
premises.
5.3 System Integrity
If a gas monitoring system should fail for any reason, it is important that
the system is capable of immediately alerting operational staff to this fact.
The sensor will indicate a system failure or mechanical defect and this
information can be utilised to initiate a warning alarm. It is good practice
to provide emergency facilities to protect against the loss of the mains power
supply.
Standby batteries can be incorporated with automatic changeover facilities, so
guaranteeing continued operation of the gas sensing system even in the event
of a plant breakdown as a result of a power supply failure.
Certainly, in critical plants, duplication or triplication of sensors is
recommended. The Trolex TX9042 or TX9044 Programmable Sensor Controller can be
programmed to operate with sensors in the multiple voting mode.
5.4 Sensor Management
A very important part of an efficient gas monitoring system is the training of
plant personnel in operation and maintenance of the sensors and the complete
monitoring system. Training facilities can be provided by qualified Trolex
application engineers.
Once a sensor installation is complete, the sensor locations and types should
be formally recorded and a planned test and maintenance procedure instituted.
5.5 Relative Density
****The relative density or buoyancy of the gas or vapour with respect to air
is a very important consideration. This determines its propensity to rise or
fall when released into the atmosphere.
Gases or vapours with a buoyancy less than air will tend to rise from the
source of release.
Conversely, gases or vapours heavier than air will tend to fall and accumulate
in concentrations for long periods of time.
This is a particular problem in pits, trenches, machine rooms, etc. Normal air
movements in and around such gas concentrations will have the inevitable
effect of producing zones of highly toxic mixtures.
This knowledge of the characteristics of the gas assists when positioning the
gas sensor.
The behaviour of the gas accumulation will also be affected by the velocity
and location of the gas release and by ambient air movement caused by
ventilation systems or draughts.
Pockets of gas can be trapped in trenches or ceiling cavities, all of which
adds to the unpredictability of critical gas concentrations.
Hydrogen | LIGHTER THAN AIR |
---|
Carbon Monoxide
Nitric Oxide| HEAVIER THAN AIR
Oxygen
Sulphur Dioxide
Chlorine
Nitrogen Dioxide
5.6 Hazardous Areas
Do not disassemble the sensor whilst in the hazardous area or use a sensor
that has a damaged housing in the hazardous area.
5.7 Evacuation
If a dangerous level of gas concentration is detected by the instrument, leave
the area immediately.
5.8 Operating Life
Electrochemical cells contain an electrolyte that is gradually consumed during
use. The average life is about two years, dependent upon the duty cycle.
The response should be checked at regular intervals.
5.9 Sensitivity
Electrochemical cells for toxic gases can be affected by other interfering
gases which may displace the subject gas being monitored. Steam laden
atmospheres and condensation can also reduce the sensitivity.
5.10 Flammable
Be aware that some toxic gases are also ‘flammable’ at high percentage
concentrations.
5.11 Biased Sensors
Some gas sensors must be continuously powered to maintain the calibration.
If the gas head is removed from any supply voltage for greater than 10
minutes, it could take 24–48 hours to restore its calibration.
CONNECTIONS
OUTPUT SIGNAL OPTIONS
TX6373 TOXIC GAS SENSOR/ TRANSMITTER 2- WIRE CURRENT LOOP OPERATION
TX6373 TOXIC GAS SENSOR/ TRANSMITTER
4- WIRE OPERATION
6.1 0.4 to 2 V Output Signal
|
---|---
A low impedance two-wire voltage output signal requiring a separate power
supply to the sensor.
This can be derived from a TX9132 Trip Amplifier or TX9042 Programmable Sensor
Controller, when one of those is used as the monitoring instrument.
This connection configuration works well up to about 2000 metres distance
between the sensor and the monitoring equipment.
Both the signal and the power supply to the sensor are being carried in the
common 0 V conductor so at some point – influenced by the length of the cable
and the resistance of the cable cores – the current flowing in the 0 V
conductor will impose an unacceptable voltage error onto the signal.
This effect can be reduced on long distance connections by increasing the size
of the cable cores, or even better, running a separate 0 V conductor to power
the sensor enabling operating distances up to 5000 metres.
APPLICATION GROUP I HAZARDOUS AREAS
6.2 4 to 20 mA Output Signal
The output signal from terminals 1 and 4 is a conventional 4 to 20 mA two
wire current regulated signal loop. Electrochemical sensors have very low
power consumption so the same loop can be used to also power the sensor.
No separate power supply is needed.
APPLICATION
GROUP I HAZARDOUS AREAS
GROUP II HAZARDOUS AREAS
GENERAL PURPOSE
6.3 5 to 15 Hz Output Signal
A square wave, frequency variable output that is proportional to the measured
value. The output device is an open collector NPN transistor.
A pull up resistor may be required at the monitoring device.
Output:| 5 to 15 Hz
(zero = 5 Hz)
(span = 15 Hz)
---|---
Maximum Voltage:| 15.4 V
Maximum Current:| 2 mA
Minimum Pulse Rise Time:| 5 V/ms
APPLICATION GROUP I HAZARDOUS AREAS
6.4 Using Gas Sensors in Hazardous Areas
6.4.1 GROUP I HAZARDOUS AREAS (MINING)
TX6373.01 TOXIC GAS SENSOR/ TRANSMITTER
All options of the TX6373.01 sensor (0.4 to 2 V, 4 to 20 mA and 5 to 15 Hz)
are certified Intrinsically Safe for use in Group I hazardous areas (Mining)
when used with approved equipment eg. TX9131 Trip Amplifier or a TX9042
Programmable Sensor Controller.
THE COMPLETE SYSTEM, BOTH SENSOR AND MONITORING DEVICE, CAN BE MOUNTED IN THE
HAZARDOUS AREA.
The interconnecting cable between the sensor and the monitoring device must
have steel wire armoured protection or a braided earth screen. The cross
sectional area of the conductors must be a minimum of 1 mm 2.
6.4.2 GROUP II HAZARDOUS AREAS (24 V dc)
TX6373.02 TOXIC GAS SENSOR/ TRANSMITTER
This version of the sensor (4 to 20 mA) is certified Intrinsically Safe for
use in Group II hazardous areas, when used in conjunction with safety
barriers.
THE SAFETY BARRIERS ARE MOUNTED IN THE SAFE AREA, ONLY THE SENSOR IS MOUNTED
IN THE HAZARDOUS AREA.
The system may be used with either zener safety barriers or isolation safety
barriers.
Group II sensor connections using zener safety barriers.
NB: IS EARTH MUST BE LESS THAN 10 OHMS LOOP RESISTANCE
Signal Safety Barrier: MTL787S+
Max. Cable Length: 1 km using 1.5 mm 2 cable conductors.
Group II sensor connections using isolation safety barriers.
Signal Isolation Barrier: Pepperal & Fuchs KFD2–CR–EX 1.30–300
Max. Cable Length: 1 km using 1.5 mm 2 cable conductors.
LED sequence on power
up Power up: Red LED flashes 3 times
Normal Operation: No LEDs illuminated
If you require any help with the use and connection of hazardous area equipment please contact the Trolex Technical Department.
CONTROLS AND INDICATORS
TX6373.84 TOXIC GAS SENSOR/ TRANSMITTER REMOTE GAS SENSING MODULE.
This version uses the same pre-calibrated gas sensing module as the TX6373.
The module is fitted into a robust metal housing which can be mounted at a
remote location where space is constricted or the operating conditions are
extremely harsh.
Connections:| 2 metres, flexible cable in a flexible armoured conduit (other
lengths available to specification – max. of 10 m)
---|---
Protection Classification:| Dust and waterproof to IP66
Housing Material:| Brass or Stainless steel
Maximum Cable Length:| Extendible up to 250 m using 1.5 mm 2 cable conductors
DISCONNECTING THE REMOTE GAS SENSING MODULE
The connecting cable between the remote gas sensing module and the Transmitter
is normally supplied connected at both ends. The cable can be disconnected via
a plug and socket connector inside the Transmitter housing for servicing or
transportation.
The Ribbon Cable Assembly must lie flat against the inside rear of the
enclosure & must be connected to the feed through in the orientation shown.
CALIBRATION
The gas sensing module will gradually change its response characteristics, by
a small amount, during normal use. The output signal is standardised so the
module can be quickly changed when necessary.
Ser vice replacement modules can be supplied by our Product Support
Department. Alternatively the gas sensing module may be re-calibrated when
required, using a Trolex TX6520 Gas Test Kit equipped with both Air and Test
Gas canisters.
8.1 Prepare to Calibrate
Connect the application tube of the gas test kit to the inlet aperture of the
gas sensing module.
When the Gas Sensing Module is setup into the CALIBRATE MODE it will instruct
the transmitted output signal of the sensor to be FIXED at a value of 0.00.
This will prevent the
possibility of false alarm signals being activated in the monitoring equipment
during the calibration process. The display will continue to show the measured
value of gas concentration during the calibration process.
This function is not operational on 4 to 20 mA, 2 wire systems.
8.3 Calibrate ZERO
Apply purge air, at a flow rate of 0.2 to 1 l/min, for a few seconds to clear
all remnants of gas.
The Gas Sensing Module will automatically return to the NORMAL measuring mode if NO pushbuttons are operated within 60 seconds.
Press CALIBRATE ZERO (5 seconds) until the indicator is flashing GREEN (3 times).
Release and the indicator will briefly show RED to denote ZERO setup.
The Gas Sensing Module will commence auto-zero.
Once the auto-zero has completed, the indicator will briefly show amber to
indicate trim mode has been entered.
TRIM MODE
Trim mode allows the output from the GSM to be adjusted to give an accurate
‘zero’ level. During this mode, the CALIBRATE ZERO button decreases the output
signal and the CALIBRATE SPAN increases it. Once set, the GSM will return
automatically to normal mode about 25 seconds after the last button press.
8.4 Calibrate SPAN
Apply test gas, at a flow rate of 0.2 to 1 l/min, for a few seconds until the
display value stabilises.
The Gas Sensing Module will automatically return to the NORMAL measuring mode if NO pushbuttons are operated within 50 seconds.
Press CALIBRATE SPAN (5 seconds) until the indicator is flashing YELLOW (3
times).
(SPAN CALIBRATION will not occur if an insufficient concentration of span gas
is present).
SCROLL the display value UP/DOWN until it concurs with the value of gas concentration marked on the test gas canister.
50 seconds after SCROLLING has ceased the gas sensing module will
automatically return to the NORMAL measuring mode.
Keep the test gas applied for a few seconds to verify the response of the
sensor.
Switch off the test gas supply.
MAINTENANCE
It is good safety practice to carry out regular preventative maintenance to confirm correct operation.
9.1 Output Signal
Check the response of the sensor at pre-determined intervals by injecting a
test gas using a Trolex TX6520.32 Gas Test Kit.
Compare the value of the display with the value marked on the test gas
canister.
9.2 Proof Test
Calibrate the TX6373 using the instructions in Section 8.
Insert an approved test meter into the signal line.
Inject a test gas using a Trolex TX6520.32 Gas Test Kit.
Compare the value on the test meter display with the measured line value.
If the value on the test meter does not match the value on the display:
Recalibrate and then carry out the proof test again
Refer to Section 8
OR change the gas sensing module, calibrate and then carry out the proof test.
Refer to Section 9.2
9.3 Gas Sensing Modules
The gas sensing modules should be changed at regular intervals to ensure
accuracy of response.
Electrochemical cells contain an electrolyte that is gradually consumed during
use.
The average life is about two years, influenced mostly by duty cycle, ambient
temperatures and humidity. The shifting response of the cell should be checked
at regular intervals.
The modules are conveniently replaceable giving a pre-calibrated standardised
output signal. They can be changed in seconds.
Service replacement modules can be supplied by our Product Support Department
on a regular basis.
Simply insert the new module into the instrument and return the original for
checking and calibration.
The sensor will transmit a LOW alarm signal if a replacement gas sensing module is not fitted within 15 seconds
9.4 Display
In addition to displaying the gas type and actual gas readings, the display
can indicate the status of the instrument.
Head Removal
If a gas sensing head is removed, the display will indicate this by showing .
The output current will fall to about 1.5 mA for 2-wire systems. On non-2-wire
systems the output signal will remain fixed for 15 seconds and then down scale
to about 3 mA.
If the head is replaced, then normal operation is resumed.
Underrange
If for any reason the signal from the head drops below the normal baseline
level (head failure for example) the display will indicate . Once the
underrange condition is cleared, then the display will return to normal.
Overrange
If the gas sensing head ‘sees’ a gas concentration of 1% or more above its
full scale output, the display will indicate .
This mode may only be cleared by cycling the power.
9.5 Remove Gas Sensing Modules (TX6373.84)
Insert a bar into one of the radial holes in the gas inlet bush (take care not
to damage the internal filter) and unscrew the gas inlet bush. Remove the
filter from the gas inlet bush. Clean or replace the filter as necessary. Fit
a new or cleaned filter to the gas inlet bush. Using a spanner, remove the
sensor retaining nut from the remote housing. Remove the gas sensing module
from the remote housing. Fit a new gas sensing module to the remote housing,
refit the sensor retaining nut and tighten. Refit the gas inlet bush and
tighten using a bar inserted into one of the radial holes, taking care not to
damage the filter.
9.6 Annual Safety Check
The main transmitter itself will not normally require maintenance or
calibration but it is advisable to return it to the Trolex Product Support
Department for an annual safety check.
9.7 Damaged Sensors
A Sensor that has been dropped or damaged in any way should be taken out of
service immediately for inspection, repair and re-calibration.
9.8 Record Keeping
Institute a regular calibration and maintenance procedure and keep a record.
Incorrect use of the Sensor or inadequate maintenance may not necessarily be
self evident in the Sensor and consequently it must be regularly checked and
maintained.
9.9 Maintenance and Calibration Log
ORDER REF TX6373 | DATE SUPPLIED |
---|---|
SERIAL No. | USER |
GAS TYPE | LOCATION |
DATE | SCHEDULED |
SENSING MODULE** | RETURN TO MANUFACTURER |
--- | --- |
APPROVALS AND CERTIFICATION
10.1 Europe (ATEX)
TX6373.01.xx Toxic Gas Sensor / Transmitter (Group I)
Ex Certificate number:| SIRA 02ATEX2052X
Ex Certification code:| I M1 Ex ia I Ma (Ta = -20°C to +60°C)
TX6373.02.12 Toxic Gas Sensor / Transmitter (Group II)
Ex Certificate number:| SIRA 02ATEX2052X
Ex Certification code:| II 1G Ex ia IIC T4 Ga (Ta = -20°C to +60°C)
Special Conditions for Safe Use
When the TX6373 is specifically required for group II, category 1 equipment,
the TX6373 should not be installed in a location where the external conditions
are conducive to the build-up of electrostatic charge as the polycarbonate
window may store an ignition-capable level of electrostatic charge.
Additionally, the equipment should only be cleaned with a damp cloth.
General Conditions for Safe Use
Prior to installation, it is essential that user refers to the above
certificate to ensure that the termination and cable parameters are fully
complied with and are compatible with the application. Copies of certificates
are available from Trolex.
**** ATEX Directive (94/9/EC)
10.2 Australia/New Zealand (ANZEx)
TX6373-series Toxic Gas Sensor / Transmitter
Ex Certificate Number:| ANZEx 12.3016X
Ex Certification Code:| Ex ia I (Ta = -20°C to +60°C)
Ex ia IIC T4 (Ta = -20°C to +60°C)
Special Conditions for Safe Use:
Prior to installation, it is essential that the user refers to the above
certificate to ensure that the termination and cable parameters are fully
complied with and are compatible with the application. Copies of certificates
are available from Trolex.
When the TX6373 is specifically required for group II, Zone 0, the TX6373
should not be installed in a location where the external conditions are
conducive to the build-up of electrostatic charge as the polycarbonate window
may store an ignitioncapable level of electrostatic charge. Additionally, the
equipment should only be cleaned with a damp cloth.
10.3 Russia (Customs Union)
Ex certificate number: | TC RU C-GB.ΓБ05.B.00356 |
---|---|
Ex certification codes: | PO Ex ia I Ma |
0 Ex ia IIC T4 Ga
Conditions of Use:
Prior to installation, it is essential that user refers to the above
certificate for any specific conditions of use. The user must ensure that the
termination and cable parameters are fully complied with and are compatible
with the application. Copies of certificates are available from Trolex.
10.4 South Africa (MASC)
Ex certificate number: | MASC MS/11-358X |
---|---|
Ex certification codes: | Ex ia I (-20°C ≤ Ta ≤ +60°C) |
Ex ia IIC T4 (-20°C ≤ Ta ≤ +60°C)
Specific Conditions of Use:
Under certain extreme circumstances, the polycarbonate window may store an
ignition-capable level of electrostatic charge. Therefore, when it is used for
applications that specifically require group II, category 1 equipment, the
TX6373 shall not be installed in a location where the external conditions are
conductive to the build-up of electrostatic charge. Additionally, the
equipment shall only be cleaned with a damp cloth.
General Conditions of Use:
Prior to installation, it is essential that user refers to the above
certificate to ensure that the termination and cable parameters are fully
complied with and are compatible with the application. Copies of certificates
are available from Trolex.
10.5 India (CIMFR)
Test report number: CIMFR/TC/P/H630
FUNCTIONAL SAFETY
11.1 Overview of Safety Integrity Level
The following instructions are applicable when the TX6373 Toxic Gas
Sensor/Transmitter is used as an element in a safety instrumented function
that is specified to achieve a Safety Integrity Level (SIL), eg, SIL 1, SIL 2,
etc.
The reliability of the TX6373 Toxic Gas Sensor/Transmitter has been
independently assessed in accordance with IEC 61508 for use in SIL
applications. The compliance with IEC 61508 includes hardware reliability
(probabilistic type failures) and measures to address systematic type
failures.
The information that follows forms the ‘Safety Manual’ required by IEC 61508-2
and is intended to allow correct product selection, system integration,
installation, operation and maintenance to enable the SIL specified for the
safety instrumented function to be achieved and maintained, as far as the
TX6373 Toxic Gas Sensor/Transmitter is concerned.
The actual SIL will depend on many system considerations that are outside the
scope of the TX6373 Toxic Gas Sensor/Transmitter and will rely on personnel
who are competent in the functional safety aspects of the various lifecycle
activities mentioned above.
11.2 SIL Suitability
The versions and configurations of the TX6373 Toxic Gas Sensor/Transmitter
identified in Table 1 in Section 11.3 below are suitable for use in gas
detection safety functions that have a specified Safety Integrity Level (SIL)
in accordance with IEC 61508 or IEC 61511 up to and including:
SIL 2 – when used in a ‘Low Demand’ safety function [1] SIL 1 – when used in a ‘High Demand’ safety function [1]
The functional safety data in Tables 1 and 2 in Section 11.3 must be taken
into account by integrators and end-users, including compliance with the
restrictions in use (Section 11.4) and all other provisions and conditions in
this manual.
System integrators and end users responsible for other lifecycle phases
(system specification, integration, installation, commissioning, operation,
maintenance, etc) need to perform assessments on the complete scope of their
activities to ensure a target SIL for the safety function is and continues to
be met.
[1] Low Demand and High Demand modes of operation are defined in IEC 61508-4,
3.5.16
11.3 Summary of the Verified Functional Safety Data
The product, configuration and Safety Manual that have been assessed are shown
in Table 1.
Product Information | Details |
---|---|
Product identification | TX6373.01.12 / TX6373.84.01.12 / TX6373.02.12 / |
TX6373.84.02.12 – Toxic Gas Detector
Product specification| See Section 4 of this manual
Product configuration| 4 to 20 mA output
Sensor types: CO, H2S, SO2, H2, NH3, NO2, C12, NO, 02
System configuration| 2/3-wire loop, or 4-wire powered connection; power
supply and load as specification (noting Group I certified equipment
requirements)
Element safety function| To produce a 4 to 20 mA output that correlates with a
specific toxic gas concentration range
Safety Manual| See Section 11 of this manual
Table 1 Basic Element Information
The hardware failure data for the TX6373 element safety function is based on an extensive analysis of field failure data with a 90% single sided confidence limit is shown in Table 2.
Parameter | Value |
---|---|
Dangerous failure rate (RD) | 3.E-07 |
Safe failure rate (As) | N/R ¹ |
Safe failure fraction (SFF) | N/R ¹ |
Element type | Type B |
Hardware fault tolerance (internal architecture) | 0 |
Diagnostic coverage (DC) | 60% |
Diagnostic test interval | N/A [²] |
Probability of Failure on Demand (PFDAVG) [oyear proof test 24hr MTTR] |
1.4E-03[³]
Probability of Failure on Demand (PFDAvG) [3mth proof test 24hr MTTR]|
3.5E-04[³]
Probability of dangerous Failure per Hour (PFH)| 3.E-07
Table 2 Hardware Failure Data
[1] Not required by Route 2H
[2] This parameter is determined by the controller being used
[3] To be conservative, no credit has been taken for effectiveness of the
diagnostics
11.4 Conditions or Restrictions for use in SIL Applications
The sections of this Installation and Operating Data Manual shall be strictly
complied with to ensure validity of the failure data and systematic safety
integrity. The following additional restrictions and conditions apply when the
unit is used in SIL applications:
-
The host controller must monitor the TX6373 Toxic Gas Sensor/Transmitter output at an appropriate frequency for the application (safety time) and initiate a safe action (eg. process shutdown, evacuation, etc) or be repaired within the MTTR assumed in the PFD calculations shown in Table 2 in Section 11.3 above, if an out-of-range (low) output signal is indicated.
-
If the MTTR or the proof test interval (T1) is different from those assumed in this document, then the PFDAVG should be re-calculated and the SIL capability re-verified accordingly (refer to the Safety Manual in Section 11.5 below.
-
The display is for indication only and is not part of the safety function.
-
The environmental limits are restricted to:
• +20 to +40°C
• relative humidity <90%. -
IEC 61508-2, 7.4.4.3.1c limits use to SIL 1 in high or continuous mode of operation when used in a non-redundant configuration.
-
The unit must be calibrated at commissioning and at 3 month intervals during operation and the sensor head replaced as indicated by the calibration check.
11.5 Proof Testing
Periodic proof tests of the element safety function must be performed to
identify any dormant failures, particularly when used in ‘low demand’ safety
functions – refer to Section 9.2 of this manual, for the proof test procedure.
(Note that calibration alone does not operate the 4 to 20 mA signal). Faults
identified by this test must be repaired within the MTTR and the unit returned
to full working order.
A suitable proof test interval (T1) should be used in order to achieve the
required average probability of failure on demand (PFDAVG). A nominal interval
of 8,760 hrs (1 year) and Mean Time to Repair (MTTR) of 24 hours has been used
in the derivation of PFDAVG for illustration purposes. If different values
are used, the PFDAVG for a non-redundant arrangement (ie. where the safety
function relies on a single element) can be re-calculated as follows:
PFDAVG = (λDU + λDD) tCE
Where tCE (the channel equivalent down time) = ( λDU / λD) (T1/2 + MTTR) +
(λDD / λD) MTTR
For redundant arrangements refer to IEC 61508-6 for the equations.
Those responsible for specifying proof testing of safety functions should
refer to IEC
61508-6:2010 clause B.3.2.5 for considerations of the effect of non-perfect
proof tests.
11.6 System Configuration Drawing
The illustration below shows how the TX6373 is to be used with other system
elements. If a controller other than the
TX9042 is used then the out of range (fault indication) signal from the TX6373
must be detected and acted upon to assert a system fault.
TROLEX LIMITED
NEWBY ROAD, HAZEL GROVE, STOCKPORT,
CHESHIRE SK7 5DY
+44 (0)161 483 1435
sales@trolex.com
www.trolex.com
References
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