Siemens SITRANS SL Safety Manual

Continuous Gas Analysis

SITRANS SL

In-situ Laser Gas Analyzer

Safety Manual

Supplement to Operating Instructions

Continuous Gas Analysis

In-situ Laser Gas Analyzers
Safety Manual

Operating Instructions

Supplement to SITRANS SL Operating Instructions

06/2012

A5E03433511-05

Introduction

1

General description of
functional safety

2

Device-specific Safety
Instructions

3

List of abbreviations

4

Legal information
Warning notice system

This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.

DANGER

indicates that death or severe personal injury will result if proper precautions are not taken.

WARNING

indicates that death or severe personal injury may result if proper precautions are not taken.

CAUTION

with a safety alert symbol, indicates that minor personal injury can result if proper precautions are not taken.

CAUTION
without a safety alert symbol, indicates that property damage can result if proper precautions are not taken.

NOTICE
indicates that an unintended result or situation can occur if the relevant information is not taken into account.

If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.

Qualified Personnel

The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.

Proper use of Siemens products

Note the following:

WARNING

Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.

Trademarks

All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.

Disclaimer of Liability

We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

Siemens AG

Industry Sector
Postfach 48 48
90026 NÜRNBERG
GERMANY

Order number: A5E03433511
Ⓟ 06/2012 Technical data subject to change

Copyright © Siemens AG
2011,2012.
All rights reserved

Safety Manual
Operating Instructions, 06/2012, A5E03433511-05

3

Table of contents

1 Introduction................................................................................................................................................ 5

1.1 Purpose of this document ..............................................................................................................5

1.2 Device description..........................................................................................................................5

1.3 Device variants ..............................................................................................................................6

1.4 Additional documentation

......................................................................................................

.........6

1.5 History............................................................................................................................................7

1.6 Further information

...........................................................................................................

..............7

2 General description of functional safety

..................................................................................................... 9

2.1 Safety-instrumented system ..........................................................................................................9

2.2 Safety integrit

y

level.....................................................................................................................10

3 Device-specific Safety Instructions .......................................................................................................... 13

3.1 Applications..................................................................................................................................13

3.2 Safety function .............................................................................................................................13

3.3 Application restrictions .................................................................................................................15

3.3.1 Temperature and pressure

......................................................................................................

....15

3.3.2 Purging.........................................................................................................................................15

3.4 Settings ........................................................................................................................................16

3.5 Behavior in case of faults....................................................................................................

.........17

3.6 Maintenance and checks ........................................................................................................

.....18

3.7 Safety characteristics...................................................................................................................20

4 List of abbrev

i

ations................................................................................................................................. 21

Glossary .................................................................................................................................................. 23

Table of contents

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5

Introduction

1

1.1 Purpose of this document

This document contains all information and safety instructions required when using the
SITRANS SL in-situ gas analyzer in safety-instrumented systems.

It addresses system planners, constructors, service and maintenance engineers and any
personnel commissioning and operating the device.

1.2 Device description

SITRANS SL is a gas analyzer employing single line molecular absorption spectroscopy. A
diode laser emits a beam of infrared light which passes through the process gas and is
detected by a receiver unit. The wavelength of the laser diode output is tuned to a gas
specific absorption line. The laser continuously scans this single absorption line with a very
high spectral resolution. The degree of absorption and the line shape are used for the
evaluation. The measurement is free of cross-interferences, since the quasi-monochromatic
laser light is absorbed very selectively by only one specific line in the scanned spectral
range.

The field design of the SITRANS SL in-situ gas analyzer consists of a transmitter unit and a
receiver unit. The light which is not absorbed by the sample is detected in the receiver. The
concentration of the gas component is determined from the absorption.

The individual dependencies of concentration, pressure and temperature are application
specific.

An internal reference cell is used to constantly check the stability of the spectrometer, thus
assuring a continuous self-calibration of the analyzer.

The self-calibration of the analyzer is therefore valid for the time period specified in the
technical data without the necessity for external recalibration using calibration gases.

Introduction

1.3 Device variants

Safety Manual

6 Operating Instructions, 06/2012, A5E03433511-05

1.3 Device variants

The following table lists all available SITRANS SL gas analyzer 4 to 20 mA variants, which
meet the specific safety requirements of IEC 61508 / IEC 61511:

Product number (MLFB) Measured component SIL level Assessment type
7MB6221-xAx0x-xxxx Oxygen (O2) SIL 1 IEC 61508 / IEC 61511 FMEDA

incl. proven-in-use

7MB6221-xJx0x-xxxx Carbon monoxide (CO) SIL 1 IEC 61508 Hardware assessment (FMEDA)

The term SITRANS SL is used in the following text for all above-mentioned devices.

1.4 Additional documentation

This document deals with the SITRANS SL in-situ laser gas analyzer exclusively as part of a
safety function. This document is valid only in conjunction with one of the following
documents:

No. Designation Order no.
/1/ SITRANS SL Operating Instructions A5E01132948 (English)

A5E01132949 (German)
A5E01132951 (French)
A5E01132952 (Italian)
A5E01132953 (Spanish)

Introduction

1.5 History

Safety Manual
Operating Instructions, 06/2012, A5E03433511-05

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1.5 History

The following table shows the released versions and the changes in the documentation
compared to each preceding edition:

Edition Remark
01

02/2011

First edition

02
06/2011

Introduction of CO as new measuring component

03
08/2011

Update of Certificate of Conformity

04
10/2011

Recalculation of safety function tolerance

05
06/2012

Proven in use for SITRANS SL O2

1.6 Further information

Information

The contents of these instructions shall not become part of or modify any prior or existing
agreement, commitment or legal relationship. All obligations on the part of Siemens AG are
contained in the respective sales contract which also contains the complete and solely
applicable warranty conditions. Any statements contained herein do not create new
warranties or modify the existing warranty.

The content reflects the technical status at the time of printing. We reserve the right for
technical changes in the course of further development.

References

If further information on an aspect described here is referenced to, the corresponding
reference will always be found at the end of a section under "See also".