FprEN 50724:2023

Fixed Ultrasonic Gas Leak Detectors (UGLD) - General requirements and test methods

This document refers to UGLDs (ultrasonic gas leak detectors). This document is applicable to ultrasonic gas leak detection equipment intended to provide an indication, alarm or other output function for the purpose of initiating automatic or manual protective action(s). This document specifies general requirements for design, testing and performance, and describes test methods that apply to UGLD. The following items are considered in this document: — Leak rates to be used to verify the detection range of UGLD — Test gas to be used (nitrogen, methane, helium, etc.) — Nozzle shape and size used at all tests leak rate tests — Gas pressure used at all leak rate tests — Time duration of each leak rate test — Test leak nozzle height from solid ground — Test leak nozzle angling relative to test UGLD — UGLD angle relative to the leak (field of coverage of the UGLD) — Wind speed, air temperature and humidity at day of test — Minimum distance to solid structures (walls, etc.) at test site — Wind velocity and direction — Installation height relative to the ground — Texture of solid ground between leak and UGLD — Background noise sources, known to interfere with UGLDs, — Specification of detection radius in 3 dimensions — Environmental limitations e.g. temperature limits on sensors — Operational requirements such as temperature, ingress protection, hazardous area classification, vibration, etc. This document is also applicable when an equipment manufacturer makes any claims regarding any special features of construction or superior performance that exceed the minimum requirements of this document. This document prescribes that all such claims are verified, and that the test procedures are extended or supplemented, where necessary, to verify the claimed performance. The additional tests are agreed between the manufacturer and test laboratory and identified and described in the test report. This document does not apply to Gas Detectors using non-ultrasonic measurements to detect a gas leak.

Ortsfeste Ultraschall-Gasleckage-Detektoren (UGLD) - Allgemeine Anforderungen und Prüfverfahren

Détecteurs de fuites de gaz à ultrasons (DFGU) fixes - Exigences générales et méthodes d’essai

Le présent document traite des détecteurs de fuites de gaz à ultrasons (DFGU). Il s’applique à l’appareil de détection de fuites de gaz par ultrasons destiné à donner une indication, générer une alarme ou remplir une autre fonction de sortie afin de déclencher une ou plusieurs actions de protection automatiques ou manuelles. Le présent document spécifie des exigences générales en matière de conception, d’essai et d’aptitude à la fonction, et décrit des méthodes d’essai applicables aux DFGU. Le présent document examine les éléments suivants: — les débits de fuite à utiliser pour vérifier la portée de détection d’un DFGU; — le gaz d’essai à utiliser (azote, méthane, hélium, etc.); — la forme et les dimensions de la buse utilisée pour tous les essais de débit de fuite; — la pression de gaz utilisée pour tous les essais de débit de fuite; — la durée de chaque essai de débit de fuite; — la hauteur de la buse d’essai de fuite par rapport à un sol dur; — l’inclinaison de la buse d’essai de fuite par rapport au DFGU soumis à essai; — l’angle du DFGU par rapport à la fuite (champ de couverture du DFGU); — la vitesse du vent, la température de l’air et l’humidité le jour de l’essai; — la distance minimale par rapport aux structures pleines (murs, etc.) sur le site d’essai; — la vitesse et la direction du vent; — la hauteur de montage par rapport au sol; — la texture du sol dur entre la fuite et le DFGU; — les sources de bruit de fond connues pour interférer avec les DFGU; — la spécification du rayon de détection dans 3 dimensions; — les restrictions environnementales (limites de température des capteurs, par exemple); — les exigences de fonctionnement telles que la température, l’indice de protection, la classification des zones dangereuses, les vibrations, etc. Le présent document s’applique également lorsqu’un constructeur de l’appareil formule des réclamations concernant des caractéristiques de construction particulières ou des performances supérieures aux exigences minimales du présent document. Le présent document prescrit de vérifier ce type de réclamations et d’étendre ou de compléter les modes opératoires d’essai, lorsque cela s’avère nécessaire, afin de contrôler les performances revendiquées. Les essais supplémentaires sont convenus entre le constructeur et le laboratoire d’essai, et sont identifiés et décrits dans le rapport d’essai. Le présent document ne s’applique pas aux détecteurs de gaz qui recourent à des mesurages non ultrasonores pour détecter une fuite de gaz.

Stacionarni ultrazvočni detektorji uhajanja plina (UGLD) - Splošne zahteve in preskusne metode

General Information

• Status: Not Published
• Publication Date: 21-Sep-2023
• ICS: 13.320 - Alarm and warning systems
• Technical Committee: CLC/TC 31 - Electrical apparatus for explosive atmospheres - General requirements
• Drafting Committee: CLC/SC 31-9 - Electrical apparatus for the detection and measurement of combustible gases to be used in industrial
• Current Stage: 5060 - Voting results sent to TC, SR - Formal Approval
• Start Date: 30-Jun-2023
• Due Date: 03-May-2023
• Completion Date: 30-Jun-2023
• Ref Project: kSIST FprEN 50724:2023 - Fixed Ultrasonic Gas Leak Detectors (UGLD) - General requirements and test methods

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 50724:2022
01-september-2022
Stacionarni ultrazvočni detektorji uhajanja plina (UGLD) - Splošne zahteve in
preskusne metode

Fixed Ultrasonic Gas Leak Detectors (UGLD) - General requirements and test methods

Détecteurs ultrasoniques fixes - Règles de performance et méthodes d'essai
Ta slovenski standard je istoveten z: prEN 50724
ICS:
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
oSIST prEN 50724:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 50724:2022
---------------------- Page: 2 ----------------------
oSIST prEN 50724:2022
EUROPEAN STANDARD DRAFT
prEN 50724
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2022
ICS -
English Version
Fixed Ultrasonic Gas Leak Detectors (UGLD) - General
requirements and test methods
Détecteurs ultrasoniques fixes - Règles de performance et To be completed
méthodes d'essai
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2022-09-30.
It has been drawn up by CLC/TC 31.

If this draft becomes a European Standard, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which

stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CENELEC in three official versions (English, French, German).

A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to

the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to

provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and

shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Project: 73279 Ref. No. prEN 50724 E
---------------------- Page: 3 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
Contents Page

European foreword .................................................................................................................................... 4

Introduction ................................................................................................................................................ 5

1 Scope ............................................................................................................................................. 6

2 Normative references ................................................................................................................... 7

3 Terms and definitions .................................................................................................................. 7

3.1 Gas properties .............................................................................................................................. 7

3.2 Types of equipment ...................................................................................................................... 7

3.3 Sensors .......................................................................................................................................... 8

3.4 Signals and alarms ....................................................................................................................... 8

4 General requirements ................................................................................................................... 9

4.1 Introduction ................................................................................................................................... 9

4.2 Design ............................................................................................................................................ 9

4.2.1 General ........................................................................................................................................... 9

4.2.2 Indication methods and devices ...............................................................................................10

4.2.3 Alarm signal ................................................................................................................................10

4.2.4 Fault signals ................................................................................................................................11

4.2.5 Adjustments ................................................................................................................................11

4.2.6 Battery-powered equipment ......................................................................................................11

4.2.7 Ultrasonic transmitter for use with separate control units ....................................................11

4.2.8 Equipment using software and/or digital technologies ..........................................................11

4.3 Labelling and marking ................................................................................................................12

4.4 Instruction manual ......................................................................................................................12

5 Test methods ..............................................................................................................................14

5.1 Introduction .................................................................................................................................14

5.2 General requirements for tests .................................................................................................14

5.2.1 Samples and sequence of tests ................................................................................................14

5.2.2 Preparation of equipment before testing .................................................................................15

5.3 Normal conditions for test .........................................................................................................16

5.3.1 General .........................................................................................................................................16

5.3.2 Test gas(es) .................................................................................................................................16

5.3.3 Power supply ..............................................................................................................................16

5.3.4 Temperature and humidity .........................................................................................................16

5.3.5 Pressure.......................................................................................................................................16

5.3.6 Rain ..............................................................................................................................................16

5.3.7 Ultrasonic background noise ....................................................................................................16

5.3.8 Acclimation time .........................................................................................................................17

5.3.9 Orientation ...................................................................................................................................17

5.3.10 Communications options ...........................................................................................................17

5.4 Test methods and performance requirements ........................................................................17

5.4.1 Test conditions ...........................................................................................................................17

5.4.2 Unpowered storage ....................................................................................................................19

5.4.3 Calibration, adjustment and repeatability ................................................................................20

5.4.4 Stability ........................................................................................................................................20

5.4.5 Alarm set point(s) .......................................................................................................................21

5.4.6 Temperature ................................................................................................................................21

5.4.7 Humidity.......................................................................................................................................21

5.4.8 Vibration ......................................................................................................................................22

5.4.9 Response point ...........................................................................................................................22

5.4.10 Time to alarm ..............................................................................................................................22

5.4.11 Battery capacity ..........................................................................................................................23

---------------------- Page: 4 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)

5.4.12 Power supply variations ............................................................................................................ 23

5.4.13 Electromagnetic compatibility .................................................................................................. 23

5.4.14 Verification of software and digital components .................................................................... 23

5.4.15 False alarm sources ................................................................................................................... 23

Annex A (informative) Title .................................................................................................................... 25

A.1 Typical mass release rate conditions ....................................................................................... 25

Annex B (informative) Title .................................................................................................................... 26

B.1 Standard test sheet .................................................................................................................... 26

Annex C (informative) Title .................................................................................................................... 27

C.1 Atmospheric absorption ............................................................................................................ 27

C.2 dB Correction tables .................................................................................................................. 31

Annex D (informative) Title .................................................................................................................... 35

Bibliography ............................................................................................................................................. 36

---------------------- Page: 5 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
European foreword

This document (prEN 50724:2022) has been prepared by CLC/TC 31 “Electrical apparatus for potentially

explosive atmospheres”.
This document is currently submitted to the Enquiry.
The following dates are proposed:
• latest date by which the existence of this (doa) dor + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
---------------------- Page: 6 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
Introduction

Ultrasonic Gas Leak Detectors (UGLDs) are being increasingly appointed to fast detect gas leaks from

pressurized systems to complement the use of point or line of sight detectors. The UGLD detects the acoustic

emission generated by the leak, which propagates omni-directionally at the speed of sound. The leak can be

detected at some distance without the gas itself needing to reach the position of the sensor. The main reason

for implementing UGLDs is to improve the response time to detect dangerous gas leaks and to improve the gas

leak detection coverage with the addition of a complementary detection method that is not affected by air flow.

In general terms, an UGLD functions by detecting the ultrasonic noise generated by gas escapes from a high-

pressure area to a low-pressure area through a small aperture (leak). In practice the technique is of value for

detecting leaks from tank/pipelines, etc running at pressures greater than 2 bar. The intensity of this airborne

ultrasound generated by a gas leak is due to a number of factors including but not limited to gas type, gas

pressure, leak size and gas temperature.

An UGLD does not detect specific gas types, measure percentage LFEL or ppm concentration level, but instead

responds to the specific ultrasonic sound generated by a pressurized gas leak. The reliable range coverage of

an UGLD is mainly determined by the leak rate of the gas leak, the atmospheric transmission of the ultrasound,

and the potential acoustic background noise that can interfere with the UGLD. The leak rate (measured in Kg/s)

is mainly determined by gas pressure and leak size, but molecular weight and gas temperature also plays a

role. The leak rate determines how fast a potentially dangerous gas cloud will be generated. In addition, physical

obstructions between the location of the leak, and the UGLD will also have an influence on the detection range

of the detector.
---------------------- Page: 7 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
1 Scope

This document refers to UGLDs (ultrasonic gas leak detectors). This document is applicable to ultrasonic gas

leak detection equipment intended to provide an indication, alarm or other output function for the purpose of

initiating automatic or manual protective action(s).

This document specifies general requirements for design, testing and performance, and describes test methods

that apply to UGLD. The following items are considered in this document:
— Leak rates to be used to verify the detection range of UGLD
— Test gas to be used (nitrogen, methane, helium, etc.)
— Nozzle shape and size used at all tests leak rate tests
— Gas pressure used at all leak rate tests
— Time duration of each leak rate test
— Test leak nozzle height from solid ground
— Test leak nozzle angling relative to test UGLD
— UGLD angle relative to the leak (field of coverage of the UGLD)
— Wind speed, air temperature and humidity at day of test
— Minimum distance to solid structures (walls, etc.) at test site
— Wind velocity and direction
— Installation height relative to the ground
— Texture of solid ground between leak and UGLD
— Background noise sources, known to interfere with UGLDs,
— Specification of detection radius in 3 dimensions
— Environmental limitations e.g. temperature limits on sensors

— Operational requirements such as temperature, ingress protection, hazardous area classification, vibration,

etc.

This document is also applicable when an equipment manufacturer makes any claims regarding any special

features of construction or superior performance that exceed the minimum requirements of this document. This

document prescribes that all such claims are verified, and that the test procedures are extended or

supplemented, where necessary, to verify the claimed performance. The additional tests are agreed between

the manufacturer and test laboratory and identified and described in the test report.

This document does not apply to Gas Detectors using non-ultrasonic measurements to detect a gas leak.

---------------------- Page: 8 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes

requirements of this document. For dated references, only the edition cited applies. For undated references, the

latest edition of the referenced document (including any amendments) applies.

EN IEC 61326-1, Electrical equipment for measurement, control and laboratory use - EMC requirements - Part

1: General requirements

EN 50271, Electrical apparatus for the detection and measurement of combustible gases, toxic gases or oxygen

- Requirements and tests for apparatus using software and/or digital technologies

IEC 60068-2-6, Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal)

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1 Gas properties
3.1.1
UGLD
Ultrasonic Gas Leak Detector
3.1.2
AGLD
Acoustic Gas Leak Detector
3.1.3
leak rate
mass flow rate from the gas leak, it is measured in Kilogram per second (kg/s)
3.2 Types of equipment
3.2.1
alarm-only equipment

equipment having an alarm but not having a numeric display or other indicating device

3.2.2
continuous duty equipment

equipment that is powered for long periods of time, but may have either continuous or intermittent sensing

3.2.3
fixed equipment
equipment that is intended to have all parts permanently installed
3.2.4
stand-alone leak detection equipment

fixed leak detection equipment that provides a conditioned electronic signal or output indication to a generally

accepted industry standard (such as 4-20 mA), intended to be utilized with stand-alone control units, or signal

processing data acquisition, central monitoring and similar systems which typically process information from

various locations and sources including, but not limited to, leak detection equipment

---------------------- Page: 9 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
3.2.5
stand-alone control unit

fixed leak detection control units intended to provide meter indication, alarm functions, output contacts and/or

alarm signal outputs when utilized with stand-alone leak detection equipment
3.3 Sensors
3.3.1
integral sensor
sensor which is integral to the main body of the equipment
3.3.2
remote sensor
sensor which is not integral to the main body of the equipment
3.3.3
sensor

assembly in which the sensing element is housed and which may also contain associated circuit components

3.4 Signals and alarms
3.4.1
Sound Pressure Level
SPL
quantity measured in dB and defined as follows:
P − P
hight low
SPL= 10* log
ref
where:
= high pressure of the acoustic wave
high
P = low pressure of the acoustic wave
low
P = reference pressure difference
ref
3.4.2
reference pressure difference

by analogy with the acoustic Pref definition, fixed to 20 µPa as an average of the hearing threshold for a

reference group of humans, Pref for ultrasonic sensor is defined, by analogy, to 20 µPa

3.4.3
measuring range

measuring range that represents the interval between the lowest measured value (in dB) and the highest

measured value
3.4.4
zero dB

measurement that corresponds to the SPL measured at the reference pressure difference

3.4.5
alarm set point

fixed or adjustable setting of the equipment that is intended to pre-set the level of ultrasonic sound pressure

level at which the equipment will automatically initiate an indication, alarm or other output function

---------------------- Page: 10 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
3.4.6
fault signal

audible, visible or other type of output, different from the alarm signal, permitting, directly or indirectly, a warning

or indication that the equipment is not working satisfactorily
3.4.7
latching alarm
alarm that, once activated, requires deliberate action to be deactivated
3.4.8
repeatability

repeatability across type is closeness of agreement between the results of measurements of the same value of

the same quantity, carried out by the same method and conditions, on the same UGLD instrument type

3.4.9
drift

variation in the equipment indication with time, at any fixed ultrasound level under constant ambient conditions

3.4.10
final indication
indication given by the equipment after stabilisation
Note 1 to entry: The stabilisation time shall be stated.
3.4.11
stabilisation

state when three successive readings of an equipment, taken at 5 s intervals, indicate no changes greater than

± 1 % of the measuring range
3.4.12
time to alarm

time interval, with the equipment in a warmed-up condition, between the time when an instantaneous release is

produced in the equipment surrounding and the time when the alarm is triggered
4 General requirements
4.1 Introduction
The equipment shall comply with the requirements of this document.

Electrical assemblies and components shall comply with the construction and test requirements of 4.2, where

applicable. In addition, parts of the UGLD intended for use in potentially explosive atmospheres are expected

to employ materials and comply with the construction and explosion protection as specified in the appropriate

regulations for explosion protection.
4.2 Design
4.2.1 General

The equipment shall be constructed in such a manner that regular functional checks can be easily undertaken

by the user and that it can be equipped with suitable devices for application of a sound source (field test kit).

Any malfunction of outputs from the detection equipment not relevant to safety or health shall not adversely

affect the functions of the equipment related to safety.

EXAMPLE Equipment with 4-20mA and Highway Addressable Remote Transducer (HART) Protocol communication

where only the 4-20 mA communication is defined in the instruction manual as related to safety. The loss of HART

communication is not related to safety.
---------------------- Page: 11 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
4.2.2 Indication methods and devices
4.2.2.1 General

Readily distinguishable indications shall be provided to show the instrument status, e.g. that the equipment is

energised, operational, in alarm or in a special state (e.g. fault or warning or inhibited).

It is permitted for the equipment output signals to indicate instrument status (e.g. energised, in alarm and special

state conditions) on the receiving control unit.

If the equipment has more than one leak detection scale, the range selected shall be clearly identified.

4.2.2.2 Display and other devices for indication of measured values

For equipment with a display to indicate the ultrasound measurement level all methods of indication of the

measured ultrasound pressure level value shall present the same value within the resolution of each indicator.

Any over-range measurements shall be clearly indicated.

For alarm-only equipment or equipment where the resolution of the read-out device is inadequate to

demonstrate compliance with this document, the manufacturer shall identify suitable methods for connecting

indicating or recording devices for the purpose of testing the compliance of the equipment with this document.

The indication on the read-out device of the equipment shall not contradict the results obtained by the indicating

or recording devices.
4.2.2.3 Indicator light

If only one indicator light is provided for signalling alarms, special states and other indications, it shall be

coloured red. If separate indicator lights are used or if a multi-coloured indicator light is provided, the colours

shall be used in the following order of priority ((a) being highest priority):

a) alarms indicating the presence of ultrasonic noise level beyond an alarm set point shall be coloured RED;

b) equipment fault or warning special state indicators shall be coloured YELLOW;
c) power supply indicators shall be coloured GREEN.

If a multi-coloured indicator light is provided, the equipment shall provide an additional indication by means other

than colour.

If there is more than one indicator light of the same colour with different functions, the lights shall be labelled to

show their functions. Text, marks, and icons on a screen display describing the indicator lights are permissible

in place of printed labels.
4.2.3 Alarm signal
4.2.3.1 Alarm settings

The audible and visual alarm settings for the equipment shall not be ambiguous. If the equipment has more

than one measuring range, the equipment shall not automatically change any existing alarm setting when

changing the measuring range.
4.2.3.2 Alarm output functions
Alarm set points shall not be adjustable outside the measuring range.

Alarms shall be latching as a factory default setting and require a deliberate manual action to reset.

Alarms shall remain in operation while the alarm condition is still present. An audible alarm may be silenced if

this audible alarm is not the only alarm.
---------------------- Page: 12 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)

If it is possible to de-activate alarm devices, output contacts or alarm signal outputs, this deactivation shall be

indicated by a signal. For fixed equipment, this shall include a contact or other transmittable output signals. The

output signal or contacts are not required if the alarms can be automatically re-enabled within 15 min.

EXAMPLE It might be necessary to de-activate alarm devices for calibration purposes.

4.2.4 Fault signals

Externally powered equipment shall provide a fault signal in the event of failure of power to the equipment.

Externally powered equipment shall provide a fault signal when the supply voltage falls below the minimum

supply voltage fault limit.

A short circuit or open circuit in connections to any remote sensor or transmitter shall be indicated by a fault

signal.
Under the above conditions the equipment may also indicate alarm.

Equipment where the sensor can be replaced without opening the housing with a tool shall provide a fault signal

in the event of a disconnection of the sensor.

The failure of an ultrasound sensor shall be indicated as a fault. If an UGLD has multiple ultrasound detectors

then the failure of any sensor shall be indicated.
4.2.5 Adjustments

All adjustment functions shall be designed so as to discourage unauthorised or inadvertent interference with the

equipment.

EXAMPLE Procedural devices, in the case of a special keyboard instrument, and/or mechanical devices such as a

cover requiring the use of a special tool.

Fixed explosion-protected equipment housed in explosion-protected enclosures shall be designed so that, if any

facilities for adjustments are necessary for routine recalibration and for resetting or functions of the like, these

facilities shall be externally accessible and shall not degrade the explosion protection of the equipment. The

instrument manual shall provide the instructions for these tasks.
The adjustments of the zero and sensitivity shall be designed so that:
a) adjustment of one will not affect the other;

b) it shall not be possible to adjust only one and the sequence of adjustments shall ensure that the affected one

is adjusted second.
4.2.6 Battery-powered equipment

Equipment powered with integral batteries shall be provided with an indication of low battery condition, and the

nature and purpose of this indication shall be explained in the manual (see 4.4 c13).

4.2.7 Ultrasonic transmitter for use with separate control units

The UGLD may output a deterministic discrete output of an alarm (gas leak) based on set thresholds and may

provide an output as a measurement, proportional to the ultrasound pressure level, to a separate control unit

along with the special states.

The manufacturer shall provide a means to interpret the output signal or indication, which will enable the

accuracy of the transfer function to be verified.
4.2.8 Equipment using software and/or digital technologies
The equipment shall fulfil the requirements of EN 50271.
---------------------- Page: 13 ----------------------
oSIST prEN 50724:2022
prEN 50724:2022 (E)
4.3 Labelling and mar
...