Water quality - On-line sensors/analysing equipment for water - Specifications and performance tests (ISO 15839:2003)

ISO 15839:2003 describes the performance testing of on-line sensors/analysing equipment for water. The standard is applicable to most sensors/analysing equipment, but it is recognized that, for some sensors/analysing equipment, certain performance tests cannot be carried out. This International Standard
defines an on-line sensor/analysing equipment for water quality measurements;defines terminology describing the performance characteristics of on-line sensors/analysing equipment;specifies the test procedures (for laboratory and field) to be used to evaluate the performance characteristics of on-line sensors/analysing equipment.

Wasserbeschaffenheit - Online-Sensoren/Analysengeräte für Wasser - Spezifikationen und Leistungsprüfungen (ISO 15839:2003)

Diese Internationale Norm beschreibt die Leistungsprüfung von Online-Sensoren/Analysengeräten für Wasser. Die Norm gilt für die meisten Sensoren/Analysengeräte, es ist jedoch bekannt, dass für einige Sensoren bzw. Analysengeräte bestimmte Leistungsprüfungen nicht durchgeführt werden können. Diese Internationale Norm
-   beschreibt einen Online-Sensor/ein Analysengerät für Messungen der Wasserbeschaffenheit;
-   legt die Begriffe fest, die die Leistungskenngrößen von Online-Sensoren/Analysengeräten beschreiben;
-   legt die anzuwendenden Prüfverfahren (für Labor- und Vor-Ort-Versuche) fest, um die Leistungskenngrö¬ßen von Online-Sensoren/Analysengeräten zu bewerten.

Qualité de l'eau - Matériel d'analyse/capteurs directs pour l'eau - Spécifications et essais de performance (ISO 15839:2003)

L'ISO 15839:2003 décrit l'essai de performance du matériel d'analyse/capteurs directs dans l'eau. Elle s'applique à la plupart des matériels d'analyse/capteurs directs; toutefois, il est admis que, pour quelques matériels d'analyse/capteurs directs, certains essais de performance ne peuvent être réalisés. L'ISO 15839:2003 définit le matériel d'analyse/capteurs directs permettant de mesurer la qualité de l'eau, définit la terminologie décrivant les caractéristiques de fonctionnement du matériel d'analyse/capteurs directs et spécifie les procédures d'essai (en laboratoire et sur le terrain) à suivre pour évaluer les caractéristiques de fonctionnement du matériel d'analyse/capteurs directs.

Kakovost vode - On-line senzorji/oprema za analizo voda - Specifikacije in preskusi delovanja (ISO 15839:2003)

General Information

Status
Published
Publication Date
22-Aug-2006
Technical Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
23-Aug-2006
Completion Date
23-Aug-2006

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SLOVENSKI STANDARD
SIST EN ISO 15839:2007
01-februar-2007
Kakovost vode - On-line senzorji/oprema za analizo voda - Specifikacije in
preskusi delovanja (ISO 15839:2003)

Water quality - On-line sensors/analysing equipment for water - Specifications and

performance tests (ISO 15839:2003)

Wasserbeschaffenheit - Online-Sensoren/Analysengeräte für Wasser - Spezifikationen

und Leistungsprüfungen (ISO 15839:2003)

Qualité de l'eau - Matériel d'analyse/capteurs directs pour l'eau - Spécifications et essais

de performance (ISO 15839:2003)
Ta slovenski standard je istoveten z: EN ISO 15839:2006
ICS:
13.060.45 Preiskava vode na splošno Examination of water in
general
SIST EN ISO 15839:2007 en,fr,de

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

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN ISO 15839
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2006
ICS 13.060.45; 13.060.01
English Version
Water quality - On-line sensors/analysing equipment for water -
Specifications and performance tests (ISO 15839:2003)

Qualité de l'eau - Matériel d'analyse/capteurs directs pour Wasserbeschaffenheit - Online-Sensoren/Analysengeräte

l'eau - Spécifications et essais de performance (ISO für Wasser - Spezifikationen und Leistungsprüfungen (ISO

15839:2003) 15839:2003)
This European Standard was approved by CEN on 10 August 2006.

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. Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists 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 Central Secretariat has the same status as the official

versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,

Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,

Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15839:2006: E

worldwide for CEN national Members.
---------------------- Page: 2 ----------------------
EN ISO 15839:2006 (E)
Foreword

The text of ISO 15839:2003 has been prepared by Technical Committee ISO/TC 147 "Water

quality” of the International Organization for Standardization (ISO) and has been taken over as

EN ISO 15839:2006 by Technical Committee CEN/TC 230 "Water analysis", the secretariat of

which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of

an identical text or by endorsement, at the latest by February 2007, and conflicting national

standards shall be withdrawn at the latest by February 2007.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of

the following countries are bound to implement this European Standard: Austria, Belgium,

Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,

Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice

The text of ISO 15839:2003 has been approved by CEN as EN ISO 15839:2006 without any

modifications.
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INTERNATIONAL ISO
STANDARD 15839
First edition
2003-10-15
Water quality — On-line
sensors/analysing equipment for water —
Specifications and performance tests
Qualité de l'eau — Matériel d'analyse/capteurs directs pour l'eau —
Spécifications et essais de performance
Reference number
ISO 15839:2003(E)
ISO 2003
---------------------- Page: 4 ----------------------
ISO 15839:2003(E)
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© ISO 2003

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ii © ISO 2003 — All rights reserved
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ISO 15839:2003(E)
Contents Page

Foreword............................................................................................................................................................ iv

1 Scope...................................................................................................................................................... 1

2 Normative references ........................................................................................................................... 1

3 Terms and definitions........................................................................................................................... 2

4 Determining on-line sensor/analysing equipment performance characteristics — An

overview................................................................................................................................................. 7

5 Determination of performance characteristics in the laboratory..................................................... 8

6 Determining performance characteristics in the field..................................................................... 15

Annex A (informative) Manufacturer/supplier information........................................................................... 20

Annex B (informative) On-line measurement chains .................................................................................... 22

Annex C (informative) Recommended test bench facilities ......................................................................... 23

Annex D (informative) Scheduling of tests .................................................................................................... 26

Annex E (informative) Examples of test reports............................................................................................ 28

Bibliography ..................................................................................................................................................... 30

© ISO 2003 — All rights reserved iii
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ISO 15839:2003(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies

(ISO member bodies). The work of preparing International Standards is normally carried out through ISO

technical committees. Each member body interested in a subject for which a technical committee has been

established has the right to be represented on that committee. International organizations, governmental and

non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the

International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 15839 was prepared by Technical Committee ISO/TC 147, Water quality.
iv © ISO 2003 — All rights reserved
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO 15839:2003(E)
Water quality — On-line sensors/analysing equipment for
water — Specifications and performance tests

WARNING — Persons using this International Standard should be familiar with normal laboratory

practice. This standard does not purport to address all of the safety problems, if any, associated with

its use. It is the responsibility of the user to establish appropriate safety and health practices and to

ensure compliance with any national regulatory conditions.
1 Scope

This International Standard describes the performance testing of on-line sensors/analysing equipment for

water. The standard is applicable to most sensors/analysing equipment, but it is recognized that, for some

sensors/analysing equipment, certain performance tests cannot be carried out. This International Standard

 defines an on-line sensor/analysing equipment for water quality measurements;

 defines terminology describing the performance characteristics of on-line sensors/analysing equipment;

 specifies the test procedures (for laboratory and field) to be used to evaluate the performance

characteristics of on-line sensors/analysing equipment.
2 Normative references

The following referenced documents are indispensable for the application 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.

ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results — Part 1: General

principles and definitions

ISO 6879:1995, Air quality — Performance characteristics and related concepts for air quality measuring

methods

ISO 8466-1:1990, Water quality — Calibration and evaluation of analytical methods and estimation of

performance characteristics — Part 1: Statistical evaluation of the linear calibration function

ISO/TR 13530:1997, Water quality — Guide to analytical quality control for water analysis

© ISO 2003 — All rights reserved 1
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ISO 15839:2003(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
accepted reference value

value that serves as an agreed reference value for comparison, and which is derived as:

a) an assigned or certified value based on experimental work of some national or international organization;

b) a consensus or certified value based on collaborative experimental work;
c) a theoretical or established value based on scientific principles;

d) when a), b) and c) are not available, the expectation of the (measurable) quantity, i.e. the mean of a

number of measurements.
[Adapted from ISO 5725-1:1994]
3.2
accuracy
closeness of agreement between a measured value and the accepted reference value

NOTE The term accuracy, when applied to a set of measured values, involves a combination of random components

and a common systematic error or bias component.
[Adapted from ISO 5725-1:1994]
3.3
analytical chain

set of instruments and actions covering all the steps involved in determining a reference value in a field test,

including sampling, fractioning, conditioning, storage and transportation of the sample to the laboratory for

analysis
3.4
availability

〈measurement chain〉 percentage of the full measurement period during which the measurement chain is

available for making measurements

NOTE The full measurement period is the period which includes all specified automatic or manual maintenance

operations at least once
cf. up-time (3.42)
3.5
bias
consistent deviation of the measured value from an accepted reference value

NOTE Bias is the total systematic error as contrasted to random error. There may be one or more systematic error

components contributing to the bias. A larger systematic difference from the accepted reference value is reflected by a

larger bias value.
[Adapted from ISO 5725-1:1994]
3.6
blank solution

solution, free of determinand, to which the on-line sensor/analysing equipment is exposed in the same way as

calibration or sample solutions
NOTE The value of the measurement is known as the “blank value”.
2 © ISO 2003 — All rights reserved
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ISO 15839:2003(E)
3.7
calibration solution

solution containing a substance or mixture of substances giving a defined value of the determinand and used

for calibration of the on-line sensor/analysing equipment
cf. reference material (3.30)
3.8
calibration procedure

set of operations that establishes, under specified conditions, the relationship between the amount or quantity

of calibrant and the response indicated by the on-line sensor/analysing equipment

3.9
coefficient of variation

ratio of the standard deviation of the on-line sensor/analysing equipment to the mean of the working range of the

equipment
[Adapted from ISO 8466-1:1990]
3.10
day-to-day repeatability
precision under day-to-day repeatability conditions
3.11
day-to-day repeatability conditions

conditions whereby independent test results are obtained with the same method on identical test items in the

same laboratory by the same operator using the same equipment and reagents over several days

3.12
delay time

time interval between the instant when the on-line sensor/analysing equipment is subjected to an abrupt

change in determinand value and the instant when the readings pass (and remain beyond) 10 % of the

difference between the initial and final value of the abrupt change

NOTE For on-line sensor/analysing equipment with a sample-handling system the delay time frequently depends on

the time needed to convey the sample from the sampling point to the analyser inlet.

cf. response time (3.33)
3.13
determinand

property/substance that is required to be measured and to be reflected by/present in a calibration solution

3.14
fall time

difference between the response time and the delay time when the abrupt change in determinand value is

negative
cf. delay time (3.12) and response time (3.33)
3.15
interference

undesired output signal caused by a property(ies)/substance(s) other than the one being measured

[ASTM D 3864-96]
3.16
interferent

component of the sample, excluding the determinand, that affects the output signal

© ISO 2003 — All rights reserved 3
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ISO 15839:2003(E)
3.17
limit of detection
LOD

lowest value, significantly greater than zero, of a determinand that can be detected

3.18
limit of quantification
LOQ

lowest value of a determinand that can be determined with an acceptable level of accuracy and precision

3.19
linearity

condition in which measurements made on calibration solutions having determinand values spanning the

stated range of the on-line sensor/analysing equipment have a straight-line relationship with the calibration

solution determinand values
3.20
long-term drift

slope of the regression line derived from a series of differences between reference and measurement values

obtained during field testing, expressed as a percentage of the working range over a 24 h period

3.21
lowest detectable change
LDC
smallest significantly measurable difference between two measurements
3.22
period between maintenance operations
time between successive maintenance operations on the measurement chain

NOTE The shortest period between maintenance operations will typically be of the order of a few hours (between two

automatic rinse operations). The longest period between maintenance operations will typically be of the order of a few

months (between services).
3.23
measurement
mean value of at least 10 consecutive readings
cf. reading (3.29)
3.24
measurement chain

set of instruments and actions that covers all the steps involved in measuring a determinand, including the on-

line sensor/analysing equipment, sampling and pretreatment, transportation and storage of the sample

3.25
memory effect

temporary or permanent dependence of readings on one or several previous values of the determinand

[Adapted from ISO 6879:1995]
3.26
on-line sensor/analysing equipment

automatic measurement device which continuously (or at a given frequency) gives an output signal

proportional to the value of one or more determinands in a solution which it measures (see Annex B)

3.27
performance characteristics

set of parameters describing the performance of the on-line sensor/analysing equipment and measurement

chain
4 © ISO 2003 — All rights reserved
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ISO 15839:2003(E)
3.28
precision

the closeness of agreement between independent measured values obtained under stipulated conditions

NOTE 1 Precision depends only on the distribution of random errors and does not relate to the true value or the

specified value.

NOTE 2 The measure of precision is usually expressed in terms of imprecision and computed as a standard deviation

of the test results. Less precision is reflected by a larger standard deviation.
[Adapted from ISO 5725-1:1994]
3.29
reading

manual or automatic registration of the on-line sensor/analysing equipment response

NOTE Readings are taken with a frequency which depends on the dynamics of the on-line sensor/analysing

equipment (i.e. on the response time — see 3.33 and 5.1.2).
3.30
reference material

substance, or mixture of substances, the composition of which is known within specified limits, and one or

more of the properties of which is sufficiently well established, over a stated period of time, to be used for the

calibration of an instrument or the assessment of a measurement method
3.31
repeatability
precision under repeatability conditions
[ISO 5725-1:1994]
3.32
repeatability conditions

conditions where independent test results are obtained with the same method on identical test items in the

same laboratory by the same operator using the same equipment and reagents within short intervals of time

(e.g. one day)
[Adapted from ISO 5725-1:1994]
cf. day-to-day repeatability conditions (3.11)
3.33
response time

time interval between the instant when the on-line sensor/analysing equipment is subjected to an abrupt

change in determinand value and the instant when the readings cross the limits of (and remain inside) a band

defined by 90 % and 110 % of the difference between the initial and final value of the abrupt change (see

5.2.1)

NOTE In laboratory testing, the response time of the on-line sensor/analysing equipment is measured. In field testing,

it is the whole measurement chain which is tested.
3.34
rise time

difference between the response time and the delay time when the abrupt change in determinand value is

positive
cf. response time (3.33)
© ISO 2003 — All rights reserved 5
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ISO 15839:2003(E)
3.35
ruggedness

on-line sensor/analysing equipment stability when the equipment is subjected to different environmental

conditions which could possibly affect its performance

NOTE Ruggedness also describes the behaviour of the equipment in the hands of different operators who will

inevitably introduce small variations in operations such as calibration and maintenance which may or may not have a

significant influence on performance.
3.36
selectivity

extent to which the on-line sensor/analysing equipment can determine a particular determinand in a complex

mixture without interference from the other components in the mixture

NOTE On-line sensor/analysing equipment which is perfectly selective for a determinand is said to be specific.

3.37
short-term drift

slope of the regression line derived from a series of measurements carried out on the same calibration

solution during laboratory testing, and expressed as a percentage of the measurement range over a 24 h

period
3.38
signal
conveyor of information about one or more determinands

NOTE An input signal is a signal applied to the on-line sensor/analysing equipment. An output signal is a signal

delivered by the equipment.
3.39
stated range

range covered by the on-line sensor/analysing equipment as stated by the manufacturer/supplier

3.40
test procedure

series of measurements performed to determine the value of a performance characteristic

3.41
test bench

test facilities which are necessary to test on-line sensor/analysing equipment or a complete measurement

chain
3.42
up-time

〈measurement chain〉 percentage of a full measurement period during which the measurement chain is

actually measuring during field testing
cf. availability (3.4)
3.43
working range

range between the lowest and highest determinand value for which tests to determine precision and bias have

been carried out
6 © ISO 2003 — All rights reserved
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ISO 15839:2003(E)
4 Determining on-line sensor/analysing equipment performance characteristics —
An overview

Determination of the performance characteristics of on-line sensors/analysing equipment has, for practical

reasons, to be divided into two parts: a laboratory test under controlled conditions and a field test under real-

life conditions. However, the route followed in each of the tests, and the information/materials needed, can be

described with the same diagram as shown in Figure 1.

The manufacturer/supplier who provides the on-line sensor/analysing equipment will also provide relevant

information concerning operation of the equipment as indicated in Annex A. Based on the equipment

properties and the different needs of measurement chains as given in Annex B, the appropriate test bench

facilities shall be constructed (recommendations for this are given in Annex C).

After construction of the test bench facilities, a preliminary determination of the sensor/analysing equipment

response time shall be carried out, providing information necessary for the timing of measurements. The

performance characteristics shall be determined in accordance with the test procedures given in Clauses 5

and 6. The test schedule shall take into account the automatic and/or manual maintenance of the

sensor/analysing equipment (see Annex D for an example). Finally, a test report shall be written (see Annex E

for examples).

Use of the guidelines outlined in ISO/TR 13530 will ensure that the precision of the results of the laboratory

tests is sufficiently high. During testing, use only reagents of recognized analytical grade.

Figure 1 — Overview of test
© ISO 2003 — All rights reserved 7
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ISO 15839:2003(E)
5 Determination of performance characteristics in the laboratory
5.1 Preparation for the test
5.1.1 Equipment

The test bench facilities (see Annex C) may be different for different on-line sensors/analysing equipment.

However, the following conditions shall be fulfilled for all on-line sensors/analysing equipment:

 The test bench facilities shall match the requirements specified for the sensor/analysing equipment by the

manufacturer/supplier.

 The facilities shall include the ability to record (manually or automatically) readings of the

sensor/analysing equipment in analog or digital form.

 Where appropriate, it shall be possible to change the calibration solution determinand value measured by

the sensor/analysing equipment within less than 10 % of the response time declared by the

manufacturer/supplier. (Typical examples where this is not appropriate are the determination of turbidity

and electrical conductivity.)

 The facilities shall include laboratory instruments for analysis of the required determinand(s). The

methods used and their precision shall be reported (see Annex E).

After receipt of the on-line sensor/analysing equipment to be tested, set up the sensor/analysing equipment

together with the appropriate test bench facilities. Report the details of the test set-up (see Annex E). Use and

maintain the sensor/analysing equipment in accordance with the instructions given by the

manufacturer/supplier. Before testing is started, prepare a test schedule taking the measurement and

maintenance periods into account (see Annex D).
5.1.2 Determination of details of measurement procedure

The working range used shall be within the declared working range. Carry out a preliminary determination of

the sensor/analysing equipment response time by changing from one calibration solution to another, thus

inducing an abrupt change. The calibration solutions used for this shall have determinand values of

approximately 20 % and 80 %, respectively, of the working range. (A typical example where this is not

appropriate is the determination of dissolved oxygen).

Expose the sensor/analysing equipment to the first calibration solution for a period equal to at least five times

the response time declared by the manufacturer/supplier before changing to the second calibration solution.

After the changeover, expose the sensor/analysing equipment to the second solution for the same length of

time. During these two periods and the changeover, record the readings of the sensor/analysing equipment.

The frequency at which readings are taken shall be at least 20 readings for each period corresponding to the

response time as declared by the manufacturer/supplier.

From the record of the readings, determine the preliminary response time as described in 5.2.1. The time

interval between readings in the subsequent laboratory test shall be approximately 10 % of the preliminary

response time. A measurement shall consist of the mean of ten consecutive readings of the sensor/analysing

equipment output signal after the signal has become stable, e.g. after a period equal to three times the

preliminary response time.

To be sure that the calibration solutions have remained stable during the test, analyse samples of the

calibration solutions before and after each test. No significant difference shall be found.

5.1.3 Monitoring the test

Although sensor/analysing equipment malfunction may be indicated automatically by the equipment's own

diagnostic system, monitor the general performance of the sensor/analysing equipment during the test using a

response chart (Figure 2). At least once a day during the test, carry out a measurement on one of the

calibration solutions (the same strength solution each time).
8 © ISO 2003 — All rights reserved
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ISO 15839:2003(E)

Plot the measurements on a response chart, along with agreed limits. If the sensor/analysing equipment fails

to comply with the limits, contact the manufacturer/supplier. Include the response chart, and details of any

corrective action taken, in the test report.
Key
X measurement No.
Y determinand value
Figure 2 — Response chart
5.2 Test procedure
5.2.1 Response times, delay times and rise and fall times

Response times, delay times and rise and fall times are derived from the record of readings made when the

calibration solution to which the sensor/analysing equipment is exposed is changed. In the laboratory, the

results apply directly to the sensor/analysing equipment, because no external sampling/sample preparation

systems, which might be necessary for field applications, are used.

Figure 3 illustrates the four different periods for an idealized record of readings made with a continuous-

reading system. If the response curve is asymmetric, the rise time and fall time may be different, i.e. the

sensor/analysing equipment may have different response and delay times for positive and negative changes.

© ISO 2003 — All rights reserved 9
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ISO 15839:2003(E)
Key
X time
Y response (%age of value of abrupt change)
1 test solution (20 %)
2 test solution (80 %)
3 delay time
4 rise time
5 fall time
6 response time
7 change

Figure 3 — On-line sensor/analysing equipment response to an abrupt change in determinand value

Figure 4 shows typical responses from real sensors/analysing equipment to a positive change and indicates

the correct way of determining the response time. Continuous-reading systems may give curves which differ

from the idealized curve in Figure 3, in which case the curve usually takes the
...

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