ISO 1928:2020

INTERNATIONAL ISO
STANDARD 1928
Fourth edition
2020-10
Coal and coke — Determination of
gross calorific value
Charbon et coke — Détermination du pouvoir calorifique supérieur
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
3.2 Symbols . 3
4 Principle . 6
4.1 Gross calorific value . 6
4.2 Net calorific value . 7
5 Reagents . 7
6 Apparatus . 9
7 Preparation of test sample .12
8 Calorimetric procedure .13
8.1 General .13
8.2 Preparing the combustion vessel for measurement .15
8.2.1 General procedure .15
8.2.2 Using a combustion aid .15
8.3 Assembling the calorimeter .15
8.4 Combustion reaction and temperature measurements .16
8.5 Analysis of products of combustion .16
8.6 Corrected temperature rise .17
8.6.1 Observed temperature rise, t − t .17
f i
8.6.2 Isoperibol and static-jacket calorimeters .17
8.6.3 Adiabatic calorimeters .18
8.6.4 Thermometer corrections .19
8.7 Reference temperature .19
9 Calibration .19
9.1 Principle .19
9.2 Calibrant .19
9.2.1 Certification conditions.19
9.2.2 Calibration conditions .19
9.3 Valid working range of the effective heat capacity .20
9.4 Ancillary contributions .20
9.5 Calibration procedure .21
9.6 Calculation of effective heat capacity for the individual test .21
9.6.1 Constant mass-of-calorimeter-water basis .21
9.6.2 Constant total-calorimeter-mass basis .22
9.7 Precision of the mean value of the effective heat capacity .23
9.7.1 Constant value of ε .23
9.7.2 ε as a function of the observed temperature rise .23
9.8 Redetermination of the effective heat capacity .23
10 Gross calorific value .24
10.1 General .24
10.2 Coal combustions .24
10.3 Coke combustions .24
10.4 Calculation of gross calorific value .25
10.4.1 General.25
10.4.2 Constant mass-of-calorimeter-water basis .25
10.4.3 Constant total-calorimeter-mass basis .26
10.4.4 ε as a function of the observed temperature rise .26
10.5 Expression of results .27
10.6 Calculation to other bases .27
11 Precision .28
11.1 Repeatability limit .28
11.2 Reproducibility limit .28
12 Calculation of net calorific value.28
12.1 General .28
12.2 Calculations .28
12.2.1 Calculation of net calorific value at constant pressure .28
12.2.2 Calculation of net calorific value at constant volume .30
13 Test report .31
Annex A (informative) Adiabatic calorimeters .32
Annex B (informative) Isoperibol and static-jacket calorimeters .36
Annex C (informative) Automated calorimeters .42
Annex D (informative) Checklists for the design of combustion tests and their procedures .45
Annex E (informative) Examples to illustrate some of the calculations used in this document .50
Annex F (informative) Safe use, maintenance and testing of calorimeter combustion vessels .56
Bibliography .62
iv © ISO 2020 – All rights reserved

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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www .iso .org/ directives
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. Details of
any patent rights identified during the d
...