1、BRITISH STANDARD BS EN ISO 7933:2004 Ergonomics of the thermal environment Analytical determination and interpretation of heat stress using calculation of the predicted heat strain The European Standard EN ISO 7933:2004 has the status of a British Standard ICS 13.180 BS EN ISO 7933:2004 This British
2、 Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2005 BSI 31 January 2005 ISBN 0 580 45323 5 National foreword This British Standard is the official English language version of EN ISO 7933:2004. It is identical with ISO 7933:2004. It supersedes
3、 BS EN 12515:1997 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee PH/9, Applied ergonomics, to Subcommittee PH/9/1, Thermal environments, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on requ
4、est to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI E
5、lectronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers
6、to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document
7、comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, pages ii to v, a blank page, pages 1 to 34, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since
8、 publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO7933 August2004 ICS13.180 SupersedesEN12515:1997 Englishversion ErgonomicsofthethermalenvironmentAnalytical determinationandinterpretationofheatstressusingcalculation ofthepredictedheatstrain(ISO7933:2004) Ergonom
9、iedesambiancesthermiquesDtermination analytiqueetinterprtationdelacontraintethermique fondessurlecalculdelastreintethermiqueprvisible (ISO7933:2004) ErgonomiederthermischenUmgebungAnalytische BestimmungundInterpretationderWrmebelastungdurch BerechnungdervorhergesagtenWrmebeanspruchung (ISO7933:2004)
10、 ThisEuropeanStandardwasapprovedbyCENon8August2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmayb
11、eobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial ve
12、rsions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPE
13、ANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO7933:2004:E Foreword This document (EN ISO 7933:2004) has bee
14、n prepared by Technical Committee ISO/TC 159 “Ergonomics“ in collaboration with Technical Committee CEN/TC 122 “Ergonomics“, 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,
15、 at the latest by February 2005, and conflicting national standards shall be withdrawn at the latest by February 2005. This document supersedes EN 12515:1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement thi
16、s 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, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorse
17、ment notice The text of ISO 7933:2004 has been approved by CEN as EN ISO 7933:2004 without any modifications. ENISO7933:2004 Reference number ISO 7933:2004(E)INTERNATIONAL STANDARD ISO 7933 Second edition 2004-08-15 Ergonomics of the thermal environment Analytical determination and interpretation of
18、 heat stress using calculation of the predicted heat strain Ergonomie des ambiances thermiques Dtermination analytique et interprtation de la contrainte thermique fondes sur le calcul de lastreinte thermique prvisible ENISO7933:2004ii ENISO7933:2004 iiiContents Page Foreword iv Introduction v 1 Scop
19、e 1 2 Normative references . 1 3 Symbols . 2 4 Principles of the method of evaluation. 5 5 Main steps of the calculation. 5 5.1 General heat balance equation 5 5.2 Calculation of the required evaporative heat flow, the required skin wettedness and the required sweat rate . 7 6 Interpretation of requ
20、ired sweat rate 8 6.1 Basis of the method of interpretation . 8 6.2 Analysis of the work situation . 8 6.3 Determination of maximum allowable exposure time (D lim ) . 9 6.4 Organization of work in the heat . 9 Annex A (normative) Data necessary for the computation of thermal balance. 10 Annex B (inf
21、ormative) Criteria for estimating acceptable exposure time in a hot work environment. 18 Annex C (informative) Metabolic rate . 20 Annex D (informative) Clothing thermal characteristics 22 Annex E (informative) Computer programme for the computation of the Predicted Heat Strain Model 24 Annex F (nor
22、mative) Examples of the Predicted Heat Strain Model computations 33 Bibliography . 34 ENISO7933:2004 iv 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 norma
23、lly 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 th
24、e 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
25、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
26、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 7933 was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 5, Ergonomics of the physical environment. This second edition c
27、ancels and replaces the first edition (ISO 7933:1989), which was based on the Required Sweat Rate index. In order to avoid any confusion and, as extensive modifications are brought to the prediction model, the name of the index has been changed to Predicted Heat Strain (PHS). ENISO7933:2004 vIntrodu
28、ction Other International Standards of this series describe how the parameters influencing the human thermoregulation in a given environment must be estimated or quantified. Others specify how these parameters must be integrated in order to predict the degree of discomfort or the health risk in thes
29、e environments. The present document was prepared to standardize the methods that occupational health specialists should use to approach a given problem and progressively collect the information needed to control or prevent the problem. The method of computation and interpretation of thermal balance
30、 is based on the latest scientific information. Future improvements concerning the calculation of the different terms of the heat balance equation, or its interpretation, will be taken into account when they become available. In its present form, this method of assessment is not applicable to cases
31、where special protective clothing (reflective clothing, active cooling and ventilation, impermeable, with personal protective equipment) is worn. In addition, occupational health specialists are responsible for evaluating the risk encountered by a given individual, taking into consideration his spec
32、ific characteristics that might differ from those of a standard subject. ISO 9886 describes how physiological parameters must be used to monitor the physiological behaviour of a particular subject and ISO 12894 describes how medical supervision must be organized. ENISO7933:2004blank ENISO7933:2004IN
33、TENRATIONAL TSANDADR IS:3397 O4002(E)1Ergonomics of the thermal environment Analytical determination and interpretation of heat stress using calculation of the predicted heat strain 1 Scope This International Standard specifies a method for the analytical evaluation and interpretation of the thermal
34、 stress experienced by a subject in a hot environment. It describes a method for predicting the sweat rate and the internal core temperature that the human body will develop in response to the working conditions. The various terms used in this prediction model, and in particular in the heat balance,
35、 show the influence of the different physical parameters of the environment on the thermal stress experienced by the subject. In this way, this International Standard makes it possible to determine which parameter or group of parameters should be modified, and to what extent, in order to reduce the
36、risk of physiological strains. The main objectives of this International Standard are the following: a) the evaluation of the thermal stress in conditions likely to lead to excessive core temperature increase or water loss for the standard subject; b) the determination of exposure times with which t
37、he physiological strain is acceptable (no physical damage is to be expected). In the context of this prediction mode, these exposure times are called “maximum allowable exposure times”. This International Standard does not predict the physiological response of individual subjects, but only considers
38、 standard subjects in good health and fit for the work they perform. It is therefore intended to be used by ergonomists, industrial hygienists, etc., to evaluate working conditions. 2 Normative references The following referenced documents are indispensable for the application of this document. For
39、dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7726, Ergonomics of the thermal environment Instruments for measuring physical quantities ISO 8996, Ergonomics of the thermal environment De
40、termination of metabolic rate ISO 9886, Ergonomics Evaluation of thermal strain by physiological measurements ISO 9920, Ergonomics of the thermal environment Estimation of the thermal insulation and evaporative resistance of a clothing ensemble ENISO7933:2004 2 3 Symbols For the purposes of this doc
41、ument, the symbols and abbreviated terms, designated below as “symbols” with their units, are in accordance with ISO 7726. However, additional symbols are used to for the presentation of the Predicted Heat Strain index. A complete list of symbols is presented in Table 1. Table 1 Symbols and units Sy
42、mbol Term Unit code = 1 if walking speed entered, 0 otherwise code = 1 if walking direction entered, 0 otherwise fraction of the body mass at the skin temperature dimensionless iskin-core weighting at time t idimensionless i1skin-core weighting at time t i1dimensionless emissivity dimensionless angl
43、e between walking direction and wind direction degrees A DuDuBois body surface area square metre A pfraction of the body surface covered by the reflective clothing dimensionless A reffective radiating area of a body dimensionless C convective heat flow watts per square metre c ewater latent heat of
44、vaporization joules per kilogram C orr,clcorrection for the dynamic total dry thermal insulation at or above 0,6 clo dimensionless C orr,Iacorrection for the dynamic total dry thermal insulation at 0 clo dimensionless C orr,totcorrection for the dynamic clothing insulation as a function of the actua
45、l clothing dimensionless C orr,Ecorrection for the dynamic permeability index dimensionless c pspecific heat of dry air at constant pressure joules per kilogram of dry air kelvin C resrespiratory convective heat flow watts per square metre c spspecific heat of the body watts per square meter per kel
46、vin D limmaximum allowable exposure time minutes D lim tremaximum allowable exposure time for heat storage minutes D limloss50maximum allowable exposure time for water loss, mean subject minutes D limloss95maximum allowable exposure time for water loss, 95 % of the working population minutes D maxma
47、ximum water loss grams D max50maximum water loss to protect a mean subject grams D max95maximum water loss to protect 95 % of the working population grams DRINK 1 if workers can drink freely, 0 otherwise dimensionless ENISO7933:2004 3Symbol Term Unit dS ibody heat storage during the last time increm
48、ent watts per square metre dS eqbody heat storage rate for increase of core temperature associated with the metabolic rate watts per square meter E evaporative heat flow at the skin watts per square metre E maxmaximum evaporative heat flow at the skin surface watts per square metre E ppredicted evaporative heat flow watts per square metre E reqrequired evaporative heat flow watts per square metre E resrespiratory evaporative heat flow watts per square metre f clclothing area factor d
