EN ISO 7726:2001

SLOVENSKI STANDARD
01-september-2002
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SIST EN 27726:2001
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Ergonomics of the thermal environment - Instruments for measuring physical quantities
(ISO 7726:1998)
Umgebungsklima - Instrumente zur Messung physikalischer Größen (ISO 7726:1998)
Ergonomie des ambiances thermiques - Appareils de mesure des grandeurs physiques
(ISO 7726:1998)
Ta slovenski standard je istoveten z: EN ISO 7726:2001
ICS:
13.180 Ergonomija Ergonomics
17.020 Meroslovje in merjenje na Metrology and measurement
splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 7726
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2001
ICS 13.180 Supersedes EN 27726:1993
English version
Ergonomics of the thermal environment - Instruments for
measuring physical quantities (ISO 7726:1998)
Ergonomie des ambiances thermiques - Appareils de Umgebungsklima - Instrumente zur Messung
mesure des grandeurs physiques (ISO 7726:1998) physikalischer Größen (ISO 7726:1998)
This European Standard was approved by CEN on 10 May 2001.
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 Management Centre 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, 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
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7726:2001 E
worldwide for CEN national Members.

Foreword
The text of the International Standard from Technical Committee ISO/TC 159 "Ergonomics" of
the International Organization for Standardization (ISO) has been taken over as an European
Standard by Technical Committee CEN/TC 122 "Ergonomics", the secretariat of which is held
by DIN.
This European Standard replaces EN 27726:1993.
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 January 2002, and conflicting national
standards shall be withdrawn at the latest by January 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United
Kingdom.
Endorsement notice
The text of the International Standard ISO 7726:1998 has been approved by CEN as a
European Standard without any modification.
NOTE: Normative references to International Standards are listed in annex ZA (normative).
Annex ZA (normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions
of any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications,
indicated by (mod.), the relevant EN/HD applies.
Publication Year Title EN/HD Year
ISO 7730 1994 Moderate thermal environments - EN ISO 7730 1995
Determination of the PMV and PPD
indices and specification of the
conditions for thermal comfort
INTERNATIONAL ISO
STANDARD 7726
Second edition
1998-11-01
Ergonomics of the thermal environment —
Instruments for measuring physical
quantities
Ergonomie des ambiances thermiques — Appareils de mesure des
grandeurs physiques
A
Reference number
ISO 7726:1998(E)
ISO 7726:1998(E)
Contents
Page
1 Scope. 1
2 Normative reference . 1
3 General . 1
4 Measuring instruments . 2
5 Specifications relating to measuring methods . 5
Annex A  Measurement of air temperature. 12
Measurement of the mean radiant temperature.
Annex B  14
Annex C  Measurement of plane radiant temperature . 28
Measurement of the absolute humidity of the air .
Annex D  35
Annex E  Measurement of air velocity. 45
Annex F  Measurement of surface temperature . 48
Annex G  Measurement of operative temperature. 49
Annex H  Bibliography. 51
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii
ISO 7726:1998(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.
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.
International Standard ISO 7726 was prepared by Technical Committee
ISO/TC 159, Ergonomics, Subcommittee SC 5, Ergonomics of the physical
environment.
This second edition cancels and replaces the first edition (ISO 7726:1985),
of which it constitutes a technical revision.
Annexes A to H of this International Standard are for information only.
iii
ISO 7726:1998(E)
Introduction
This document is one of a series of International Standards intended for
use in the study of thermal environments.
This series of International Standards deals in particular with
— the finalization of definitions for the terms to be used in the methods of
measurement, testing or interpretation, taking into account standards
already in existence or in the process of being drafted;
— the laying down of specifications relating to the methods for measuring
the physical quantities which characterize thermal environments;
— the selection of one or more methods for interpreting the parameters;
— the specification of recommended values or limits of exposure for the
thermal environments coming within the comfort range and for extreme
environments (both hot and cold);
— the specification of methods for measuring the efficiency of devices or
processes for personal or collective protection from heat or cold.
Any measuring instrument which achieves the accuracy indicated in this
International Standard, or even better improves on, may be used.
The description or listing of certain instruments in the annexes can only
signify that they are "recommended", since characteristics of these
instruments may vary according to the measuring principle, their
construction and the way in which they are used. It is up to users to
compare the quality of the instruments available on the market at any given
moment and to check that they conform to the specifications contained in
this International Standard.
iv
©
INTERNATIONAL STANDARD  ISO ISO 7726:1998(E)
Ergonomics of the thermal environment — Instruments for
measuring physical quantities
1 Scope
This International Standard specifies the minimum characteristics of instruments for measuring physical quantities
characterizing an environment as well as the methods for measuring the physical quantities of this environment.
It does not aim to define an overall index of comfort or thermal stress but simply to standardize the process of
recording information leading to the determination of such indices. Other International Standards give details of the
methods making use of the information obtained in accordance with this standard.
This International Standard is used as a reference when establishing
a) specifications for manufacturers and users of instruments for measuring the physical quantities of the
environment;
b) a written contract between two parties for the measurement of these quantities.
It applies to the influence of hot, moderate, comfortable or cold environments on people.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the edition indicated was valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent edition of the standard indicated below. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 7730:1994, Moderate thermal environments — Determination of the PMV and PPD indices and specification of
the conditions for thermal comfort.
3 General
3.1 Comfort standard and stress standard
The specifications and methods contained in this International Standard have been divided into two classes
according to the extent of the thermal annoyance to be assessed.
The type C specifications and methods relate to measurements carried out in moderate environments approaching
comfort conditions (comfort standard).
The type S specifications and methods relate to measurements carried out in environments subject to a greater
thermal stress or even environments of extreme thermal stress (heat stress standard).
The specifications and methods described for each of these classes have been determined bearing in mind the
practical possibilities of in situ measurements and the performances of measuring instruments available at present.
©
ISO
ISO 7726:1998(E)
3.2 Physical quantities characterizing the environment
3.2.1 Introduction
The determination of overall indices of comfort or thermal stress requires knowledge of physical quantities
connected with the environment. These quantities can be divided into two categories according to their degree of
dependence on the environment.
3.2.2 Basic physical quantities
Each of the basic physical quantities characterizes one of the factors of the environment independently of the
others. They are often used to define the indices of comfort or thermal stress based on the rationalization of the
establishment of the thermal balance of a person placed in a given thermal environment. These quantities are as
follows:
a) air temperature, expressed in kelvins ( ) or in degrees Celsius ( );
T t
a a
b) mean radiant temperature expressed in kelvins T , or in degrees Celsius t plane radiant temperature
() ()
r r
expressed in kelvins (T ) or in degrees Celsius (t ) direct radiation expressed in watts per square metre;
pr pr
c) absolute humidity of the air, expressed by partial vapour pressure (p ) in kilopascals;
a
d) air velocity (V ), expressed in metres per second;
a
e) surface temperature, expressed in kelvins (T ), or in degrees Celsius (t ).
s s
The connections between these quantities and the various gains and losses of heat in relation to the human body
are shown in table 1. Table 1 also gives four other quantities which, because they are usually estimated from data
tables rather than measured, are not included in the remainder of this International Standard.
NOTE —  The concept of mean radiant temperature allows the study of radiative exchanges between man and his
environment. It presupposes that the effects on man of the actual environment which is generally heterogeneous and the virtual
environment which is defined as homogeneous are identical. When this hypothesis is not valid, in particular in the case of
asymmetric radiation, the radiation exchanges arising from thermally different regions and the extent of their effect on man
should also be assessed using the concept of plane radiant temperature.
3.2.3 Derived physical quantities
The derived physical quantities characterize a group of factors of the environment, weighted according to the
characteristics of the sensors used. They are often used to define an empirical index of co
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