oSIST prEN 18069:2025
(Main)Water quality - Minimum requirements for the selection, installation, validation, and operation of continuous measuring devices
Water quality - Minimum requirements for the selection, installation, validation, and operation of continuous measuring devices
8. Scope
Continuous monitoring enables to measure water quality parameters that are essential for water monitoring to be tracked over sufficiently short time intervals to be able to conduct a detailed study of temporal variability. It offers the particular advantage of acquiring representative data of variations in water, compared with spot sampling campaigns conducted at fixed intervals which can miss significant events such as a concentration peak during a flood or rainfall episode.
Moreover, in the event of pollution due to industrial accidents or transport on inland waterways for example, it is vital to be able to detect these events as early as possible and react rapidly to limit their impacts on the environment and thereby indirectly protect the drinking water resource.
Consequently, the choice of having recourse to continuous measuring devices is directly linked to the advantages of obtaining a rapid measurement (a few seconds to a few minutes) at short time intervals (from a few seconds to a few hours) and in most cases in real time. Furthermore, it is possible to use the resulting measurements to automatically trigger actions, such as taking a sample for further analysis and/or stopping pumping of the drinking water resource.
To set up a continuous measurement system, it is recommended to follow a procedure that comprises 5 main steps:
1) defining the purposes of the measurements and the associated data quality requirements;
2) selecting appropriate measuring devices;
3) installing the measuring devices and setting their parameters;
4) preliminary validation under real conditions: performance verification and maintenance optimisation;
5) operational implementation.
This document describes the good practices and gives recommendations for each of the abovementioned steps.
This document applies to continuous measuring devices for monitoring physical-chemical parameters in different types of water, including continental fresh waters, marine waters, drinking water and urban and industrial wastewaters, as well as the monitoring of industrial processes.
The continuous measuring devices include single-parameter or multi-parameter in situ probes, sensors and on-line analysers.
Richtlinien für die Installation und betriebliche Implementierung von kontinuierlichen Messsystemen
Dieses Dokument legt Anforderungen an die Auswahl, Installation, Qualifizierung und den Betrieb von kontinuierlichen Messgeräten (CMDs, en: continuous measuring devices) fest. Das übergeordnete Ziel ist, repräsentative und zuverlässige Messwerte bei der Verwendung von CMDs für das Monitoring der Wasserbeschaffenheit zu erhalten.
Dieses Dokument gilt für kontinuierliche Messgeräte zur Überwachung physikalischer und chemischer Parameter in unterschiedlichen Arten von Wasser.
Qualité de l'eau - Exigences minimales pour l'installation, la mise en service, la maintenance et la mise en œuvre opérationnelle de dispositifs de mesure en continu
Le présent document spécifie les exigences relatives au choix, à l'installation, à la qualification, et à l'exploitation des dispositifs de mesure en continu (DMC). L'objectif global est d'obtenir des mesures représentatives et fiables lors de l'utilisation de DMC pour surveiller la qualité de l'eau.
Le présent document s'applique aux dispositifs de mesure en continu destinés à la surveillance de paramètres physiques et chimiques dans différents types d'eau.
Kakovost vode - Minimalne zahteve za izbiro, namestitev, validacijo in delovanje merilnikov za kontinuirano merjenje
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2025
Kakovost vode - Minimalne zahteve za izbiro, namestitev, validacijo in delovanje
merilnikov za kontinuirano merjenje
Water quality - Minimum requirements for the selection, installation, validation, and
operation of continuous measuring devices
Richtlinien für die Installation und betriebliche Implementierung von kontinuierlichen
Messsystemen
Qualité de l'eau - Exigences minimales pour l'installation, la mise en service, la
maintenance et la mise en œuvre opérationnelle de dispositifs de mesure en continu
Ta slovenski standard je istoveten z: prEN 18069
ICS:
13.060.45 Preiskava vode na splošno Examination of water in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2025
ICS 13.060.45
English Version
Water quality - Minimum requirements for the selection,
installation, validation, and operation of continuous
measuring devices
Qualité de l'eau - Exigences minimales pour le choix, Wasserbeschaffenheit - Mindestanforderungen für die
l'installation, la validation et l'exploitation de Auswahl, Installation, Validierung und den Betrieb von
dispositifs de mesure en continu kontinuierlichen Messgeräten
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 230.
If this draft becomes a European Standard, CEN 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 CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 18069:2025 E
worldwide for CEN national Members.
Contents Page
Introduction . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Selection, installation, validation and operation of continuous measuring devices . 8
4.1 General. 8
4.2 Selection . 9
4.3 Installation and verification . 13
4.4 Validation . 14
4.5 Operation . 14
Annex A (informative) Examples of quality and/or performance requirements for water
monitoring . 20
Annex B (informative) Questionnaire relative to the characteristics of a measuring point for
water monitoring - example . 21
Annex C (informative) Example of calibration criteria, verification procedure and
measurement standards for continuous measuring stations for surface water quality
monitoring . 23
C.1 Calibration criteria . 23
C.2 Calibration verification procedure . 23
C.3 Measurement standards for calibration and/or adjustment . 25
Annex D (informative) Method of correcting drifts and examples of data post-processing . 28
D.1 Method of correcting drifts based on USGS (2006) . 28
D.2 Examples of data post-processing . 29
D.3 Data confidence index . 31
Bibliography . 32
Introduction
The continuous monitoring of water quality parameters can provide real time information on temporal
variability compared with sampling campaigns conducted at fixed intervals which can miss significant
events such as a concentration peak during a flood or rainfall episode.
Moreover, in the event of pollution due to industrial accidents or transport on inland waterways for
example, it is vital to be able to detect these events as early as possible and react rapidly to limit their
impacts on the environment and possible drinking water resource.
Consequently, the choice of having recourse to continuous measuring devices (CMDs) is directly linked
to the advantages of obtaining a rapid measurement (a few seconds to a few minutes) at short time
intervals (from a few seconds to a few hours) and in most cases in real time. Furthermore, it is possible
to use the resulting measurements to automatically trigger actions, such as taking a sample for further
analysis and/or stopping pumping of a drinking water resource.
In order to obtain representative and reliable measurements when using CMDs to monitor water quality,
this document specifies minimum requirements for the following four steps:
1) Selection: defining the user requirements, the purposes of the required measurements, associated
data quality requirements, and choice of CMDs.
2) Installation: verifying a complete and correct delivery of the procured CMD and verifying a correctly
functioning on-site installation, operation and communication of the CMD.
3) Validation: verifying that the correctly installed CMD meets all of the original defined requirements.
4) Operation: implementing operating and maintenance procedures, processing of data and document
traceability.
This document is associated with EN 17075 which specifies general requirements and performance test
procedures for portable and fixed position continuous measuring devices that are used in an in-line or
online operating position to measure physical and chemical measurands in water.
Continuous measuring devices are widely used for compliance monitoring purposes under national and
European regulations.
1 Scope
This document specifies requirements for the selection, installation, qualification, and operation of
continuous measuring devices (CMDs). The overall objective is to obtain representative and reliable
measurements when using CMDs to monitor water quality.
This document applies to continuous measuring devices for monitoring physical and chemical
parameters in different types of water.
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 17075:2018+A1:2023, Water quality - General requirements and performance test procedures for
water monitoring equipment - Continuous measuring devices
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology 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
continuous measuring device (CMD)
component or a group of components, used in an in-line or on-line operating position, which continuously
(or at a given frequency) gives an output signal proportional to the value of one or more measurands in
waters which it measures
Note 1 to entry: The device can be portable or fixed in position.
[SOURCE: EN 17075]
3.2
sensor
electronic device that senses a physical condition or chemical compound and delivers an electronic signal
proportional to the observed characteristic
[SOURCE: EN 17075]
3.3
in-line continuous measuring device
in-situ continuous measuring device
system of automatic measurement which at least the sensor is sited in the body of water
[SOURCE: EN 17075]
3.4
on-line continuous measuring device
system of automatic measurement in which the sample is taken from the body of water by means of an
appropriate conduit to the CMD
Note 1 to entry: Sometimes referred to as an extractive continuous measuring device.
[SOURCE: Adapted from EN 17075]
3.5
measuring point
geographical location of the site at which the measurement is taken
3.6
outlier
member of a set of values which is inconsistent with the other members of that set
[SOURCE: ISO 5725-1]
3.7
reference method
method, material or device to be used to obtain the measurand value of the test waters, against which the
readings from the CMD used can be compared
[SOURCE: adaptated from EN 17075]
3.8
calibration
operation that, under specified conditions, in a first step, establishes a relation between the quantity
values with measurement uncertainties provided by measurement standards and corresponding
indications with associated measurement uncertainties and, in a second step, uses this information to
establish a relation for obtaining a measurement result from an indication
Note 1 to entry: A calibration may be expressed by a statement, calibration function, calibration diagram,
calibration curve, or calibration table. In some cases, it may consist of an additive or multiplicative correction of the
indication with associated measurement uncertainty.
Note 2 to entry: Calibration should not be confused with adjustment of a measuring system, often mistakenly called
“self-calibration”, nor with verification of calibration.
[SOURCE: VIM 2012, 2.39]
3.9
adjustment of a measuring system
set of operations carried out on a measuring system so that it provides prescribed indications
corresponding to given values of a quantity to be measured
Note 1 to entry: Types of adjustment of a measuring system include zero adjustment of a measuring system, offset
adjustment, and span adjustment (sometimes called gain adjustment).
Note 2 to entry: Adjustment of a measuring system should not be confused with calibration, which is a prerequisite
for adjustment.
Note 3 to entry: After an adjustment of a measuring system, the measuring system must usually be recalibrated.
Series of operations performed on a measuring system so that it delivers prescribed indications corresponding to
given values of the quantities to measure
[SOURCE: VIM 2012, 3.11]
3.10
verification
provision of objective evidence that a given item fulfils specified requirements
Note 1 to entry: When applicable, measurement uncertainty should be taken into consideration.
Note 2 to entry: The item may be, e.g. a process, measurement procedure, material, compound, or measuring
system.
Note 3 to entry: The specified requirements may be, e.g. that a manufacturer's specifications are met.
Note 4 to entry: Verification in legal metrology, as defined in VIML [53], and in conformity assessment in general,
pertains to the examination and marking and/or issuing of a verification certificate for a measuring system.
Note 5 to entry: Verification should not be confused with calibration. Not every verification is a validation.
[SOURCE: VIM 2012, 2.44]
3.11
validation
verification, where the specified requirements are adequate for an intended use
[SOURCE: VIM 2012, 2.45]
3.12
measurement standard
realization of the definition of a given quantity, with stated quantity value and associated measurement
uncertainty, used as a reference verification, where the specified requirements are adequate for an
intended use
[SOURCE: VIM 2012, 5.1]
...
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