Characterization of waste - Determination of gross calorific value and calculation of net calorific value

This Technical Specification specifies a simplified method for the determination of the gross calorific value of waste at constant volume and at the reference temperature of 25 °C in a bomb calorimeter calibrated by combustion of certified benzoic acid. This Technical Specification does not include thermo-chemical corrections. This Technical Specification also specifies a simplified calculation of the net calorific value from the gross calorific value. This Technical Specification is applicable for the evaluation of suitability of waste to be treated by thermal processes and for the energy to be recovered. This Technical Specification is applicable to all kinds of waste.

Charakterisierung von Abfällen - Bestimmung des Brennwertes und Berechnung des Heizwertes

Diese Europäische Norm legt ein Verfahren zur Bestimmung des Brennwertes für flüssige oder feste Abfälle bei konstantem Volumen und bei einer Bezugstemperatur von 25 °C in einem Bombenkalorimeter fest, das durch die Verbrennung zertifizierter Benzoesäure kalibriert wurde.
Das Prüfergebnis ist der Brennwert der Analysenprobe bei konstantem Volumen, bei dem sowohl das Wasser in den Verbrennungsprodukten als auch das in den Abfällen enthaltene Wasser in flüssigem Zustand vorliegen. In der Praxis werden Abfälle bei konstantem (atmosphärischem) Druck verbrannt, wobei das Wasser nicht kondensiert, sondern als Wasserdampf zusammen mit den Abgasen abgeführt wird. Unter diesen Bedingungen ist die zu berücksichtigende effektive Verbrennungswärme der Heizwert des Brennstoffs bei konstantem Druck. In dieser Europäischen Norm wird der Heizwert bei konstantem Volumen beschrieben, da seine Ermittlung weniger zusätzliche Bestimmungen erforderlich macht, der Wert aber auch eine für die Gebrauchstauglichkeit ausreichende Genauigkeit bietet.
Das Verfahren ist auf alle Abfallarten anwendbar.

Caractérisation des déchets - Détermination du pouvoir calorifique brut et calcul du pouvoir calorifique net

La présente Norme européenne spécifie une méthode de détermination du pouvoir calorifique supérieur des déchets liquides ou solides, à volume constant et à la température de référence de 25 °C dans une bombe calorimétrique étalonnée par combustion d’acide benzoïque certifié.
Le résultat obtenu est le pouvoir calorifique supérieur de l’échantillon à volume constant, l’eau des produits de combustion et l’humidité des déchets étant à l’état liquide. Dans la pratique, les déchets sont brûlés à pression (atmosphérique) constante et l’eau n’est pas condensée mais retirée sous forme de vapeur avec les produits de combustion. Dans ces conditions, la chaleur effective de la combustion à utiliser est le pouvoir calorifique inférieur du combustible, à pression constante. La présente Norme européenne décrit le pouvoir calorifique inférieur à volume constant, car cela nécessite moins de déterminations supplémentaires mais permet d’obtenir une précision adéquate.
La présente méthode s’applique à tous les types de déchets.

Karakterizacija odpadkov - Določevanje sežigne vrednosti in izračun kurilne vrednosti

Ta tehnična specifikacija določa poenostavljeno metodo za določevanje sežigne vrednosti odpadkov pri stalni prostornini in referenčni temperaturi 25 °C v bombnem kalorimetru, ki je kalibriran s postopkom zgorevanja certificiranih benzojskih kislin. Ta tehnična specifikacija ne vključuje termokemičnih popravkov. Ta tehnična specifikacija določa tudi poenostavljen način izračuna kurilne vrednosti iz sežigne vrednosti. Ta tehnična specifikacija se lahko uporablja za ocenjevanje primernosti odpadkov za obdelavo s termičnimi procesi in za energijo, ki se na ta način pridobi. Ta tehnična specifikacija se lahko uporablja za katero koli vrsto odpadkov.

General Information

Status
Published
Public Enquiry End Date
19-May-2012
Publication Date
01-Jun-2014
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
21-Mar-2014
Due Date
26-May-2014
Completion Date
02-Jun-2014

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SLOVENSKI STANDARD
SIST-TS CEN/TS 16023:2014
01-julij-2014
.DUDNWHUL]DFLMDRGSDGNRY'RORþHYDQMHVHåLJQHYUHGQRVWLLQL]UDþXQNXULOQH
YUHGQRVWL

Characterization of waste - Determination of gross calorific value and calculation of net

calorific value
Charakterisierung von Abfällen - Bestimmung des Brennwertes und Berechnung des
Heizwertes

Caractérisation des déchets - Détermination du pouvoir calorifique brut et calcul du

pouvoir calorifique net
Ta slovenski standard je istoveten z: CEN/TS 16023:2013
ICS:
13.030.01 Odpadki na splošno Wastes in general
SIST-TS CEN/TS 16023:2014 en,fr,de

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

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SIST-TS CEN/TS 16023:2014
TECHNICAL SPECIFICATION
CEN/TS 16023
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
November 2013
ICS 13.030.01
English Version
Characterization of waste - Determination of gross calorific value
and calculation of net calorific value

Caractérisation des déchets - Détermination du pouvoir Charakterisierung von Abfällen - Bestimmung des

calorifique supérieur et calcul du pouvoir calorifique Brennwertes und Berechnung des Heizwertes

inférieur

This Technical Specification (CEN/TS) was approved by CEN on 6 August 2013 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their

comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available

promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)

until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United

Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16023:2013: E

worldwide for CEN national Members.
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Contents Page

Foreword ..............................................................................................................................................................3

Introduction .........................................................................................................................................................4

1 Scope ......................................................................................................................................................5

2 Normative references ............................................................................................................................5

3 Terms and definitions ...........................................................................................................................5

4 Principle ..................................................................................................................................................6

4.1 Gross calorific value .............................................................................................................................6

4.2 Net calorific value ..................................................................................................................................6

5 Reagents .................................................................................................................................................6

6 Apparatus ...............................................................................................................................................7

7 Sample storage ......................................................................................................................................8

8 Sample preparation ...............................................................................................................................8

9 Procedure ...............................................................................................................................................9

9.1 General ....................................................................................................................................................9

9.2 General preparations, measurements and temperature corrections ............................................ 10

9.3 Calibration ........................................................................................................................................... 13

9.4 Samples ............................................................................................................................................... 13

10 Calculation of effective heat capacity............................................................................................... 14

11 Gross calorific value .......................................................................................................................... 15

12 Calculation of net calorific value....................................................................................................... 16

12.1 General ................................................................................................................................................. 16

12.2 Net calorific value at constant pressure .......................................................................................... 16

13 Expression of results ......................................................................................................................... 16

14 Quality control ..................................................................................................................................... 17

15 Test report ........................................................................................................................................... 17

Annex A (informative) Example of a calorimeter .......................................................................................... 18

Annex B (informative) Temperature evolution .............................................................................................. 19

Annex C (informative) Calculation of the gross calorific value – Correct calculation versus the

simplified calculation ......................................................................................................................... 20

C.1 Correct calculation ............................................................................................................................. 20

C.2 Sulfur correction ................................................................................................................................. 21

C.3 Nitrogen correction............................................................................................................................. 21

C.4 Halogens correction ........................................................................................................................... 21

C.5 Influence of the thermo-chemical corrections ................................................................................. 22

Annex D (informative) Typical hydrogen contents in waste products ....................................................... 24

Annex E (informative) Summary of general requirements and recommendations ................................... 25

Bibliography ..................................................................................................................................................... 26

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Foreword

This document (CEN/TS 16023:2013) has been prepared by Technical Committee CEN/TC 292

“Characterization of waste”, the secretariat of which is held by NEN.

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

rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

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

countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,

Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,

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

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

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Introduction

This method is a quick and easy way to evaluate the suitability of waste to be treated by thermal processes.

The determination of gross calorific value is carried out without thermo-chemical corrections. These

corrections typically result in minor changes of the result. The influence of these corrections is shown in

Annex C.

The result obtained is the gross calorific value at constant volume with both the water of the combustion

products and the moisture of the waste as liquid water.

The net calorific value is obtained by calculation from the gross calorific value. For the purpose of this

Technical Specification, the value of the net calorific value does not need to be determined exactly. The

correction for hydrogen is simplified by the use of typical hydrogen contents derived from table values of

hydrogen contents in common types of waste.

This Technical Specification specifies a quick method to determine calorific value; a more comprehensive

analysis is described in ISO 1928.

Waste can contain water and (unburnable) solids in large amounts. Therefore their calorific value – especially

on the “as received” basis – can be quite low. For some purposes it may be sufficient to determine the gross

calorific value only, and not the net calorific value.

WARNING — Strict adherence to all of the provisions prescribed in this Technical Specification

should ensure against explosive rupture of the bomb, or a blow-out, provided that the bomb is of

proper design and construction and in good mechanical condition. Anyone dealing with waste and

sludge analysis is required to be aware of the typical risks of this kind of material irrespective of the

parameter to be determined. Waste and sludge samples may contain hazardous (e.g. toxic, reactive,

flammable, infectious) substances, which can be liable to biological and/or chemical reaction.

Consequently, it is recommended that these samples be handled with special care. The gases that

may be produced by microbiological or chemical activity are potentially flammable and will pressurize

sealed bottles. Bursting bottles are likely to result in hazardous shrapnel, dust and/or aerosol.

National regulations should be followed with respect to all hazards associated with this method.

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1 Scope

This Technical Specification specifies a simplified method for the determination of the gross calorific value of

waste at constant volume and at the reference temperature of 25 °C in a bomb calorimeter calibrated by

combustion of certified benzoic acid. This Technical Specification does not include thermo-chemical

corrections.

This Technical Specification also specifies a simplified calculation of the net calorific value from the gross

calorific value.

This Technical Specification is applicable for the evaluation of suitability of waste to be treated by thermal

processes and for the energy to be recovered.
This Technical Specification is applicable to all kinds of waste.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.

EN 13965-2:2010, Characterization of waste - Terminology - Part 2: Management related terms and

definitions

EN 14346, Characterization of waste - Calculation of dry matter by determination of dry residue or water

content
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 13965-2:2010 and the following

apply.
3.1
corrected temperature rise

change in calorimeter temperature caused solely by the processes taking place within the combustion bomb

Note 1 to entry: It is the total observed temperature rise corrected for heat exchange, stirring power etc.

3.2
gross calorific value at constant volume

absolute value of the specific energy of combustion, in Joules, for unit mass of waste burned in oxygen in a

calorimetric bomb under the conditions specified

Note 1 to entry: The products of combustion are assumed to consist of gaseous oxygen, nitrogen, carbon dioxide and

sulfur dioxide, of liquid water (in equilibrium with its vapour) saturated with carbon dioxide under the conditions of the

bomb reaction, and of solid ash, all at the reference temperature.
3.3
net calorific value at constant pressure

absolute value of the specific energy of combustion, in Joules, for unit mass of waste burned in oxygen at

constant pressure under such conditions that all the water of the reaction products remains as water vapour

(in a hypothetical state at 0,1 MPa)

Note 1 to entry: The other products are assumed to remain at the reference temperature.

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4 Principle
4.1 Gross calorific value

A weighed portion of the waste sample is burned in a high-pressure oxygen atmosphere in a bomb

calorimeter under specified conditions. The effective heat capacity of the calorimeter is determined in

calibration experiments by combustion of certified benzoic acid under similar conditions, accounted for in the

certificate. The corrected temperature rise is established from observations of temperature before, during and

after the combustion reaction takes place. The duration and frequency of the temperature observations

depend on the type of calorimeter used. Water is added to the bomb initially to give a saturated vapour phase

prior to combustion, thereby allowing all the water formed, from the hydrogen and moisture in the sample, to

be regarded as liquid water.

The gross calorific value is calculated from the corrected temperature rise and the effective heat capacity of

the calorimeter, without corrections made for contributions from ignition energy, combustion of the fuse(s) and

for thermal effects from side reactions such as the formation of nitric acid.
4.2 Net calorific value

The net calorific value at constant pressure is calculated from the gross calorific value at constant volume

using typical values of hydrogen content. The calculation is made without corrections due to the oxygen and

nitrogen content of the samples.
5 Reagents

5.1 Oxygen, at a pressure high enough to fill the bomb to 3 MPa, pure with an assay of at least 99,5 %

(V/V), and free from combustible matter.

NOTE Oxygen made by the electrolytic process can contain up to 4 % (V/V) hydrogen.

5.2 Ignition wire, of nickel-chromium 0,16 mm to 0,20 mm in diameter, platinum 0,05 mm to 0,10 mm in

diameter, or another suitable conducting wire with well-characterized thermal behaviour during combustion.

Knowing the gross calorific value of the fuse is necessary if an accurate calculation according to Annex C is to

be carried out. This information is not required for the method described in this Technical Specification.

5.3 Cotton fuse, of cellulose cotton, or equivalent, if required.

Knowing the gross calorific value of the fuse is necessary if an accurate calculation according to Annex C is to

be carried out. This information is not required for the method described in this specification. It is necessary to

use a fuse with the same length and sections both in the calibration step and in the measurements.

5.4 Combustion aids, of known gross calorific value, composition and purity, such as benzoic acid,

n-dodecane, paraffin oil, combustion bags or capsules may be used.

5.5 Benzoic acid, of calorimetric-standard quality, certified by (or with certification unambiguously

traceable to) a recognized standardizing authority.

The benzoic acid is burned in the form of pellets. It is normally used without drying or any treatment other than

pelletising; consult the sample certificate. The benzoic acid shall be used as close to certification conditions as

is feasible; significant modifications to the conditions specified should be accounted for in accordance with the

directions in the certificate.
5.6 Gelatine or acetobutyrate capsules.
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6 Apparatus
6.1 General

The calorimeter (see Figure A.1), consists of the assembled combustion bomb, a can (with or without lid),

stirrer, water, temperature sensor, and leads with connectors inside the calorimeter can, required for ignition

of the sample or as part of temperature measurement or control circuits. During measurements, the

calorimeter is enclosed in a thermostat. The manner in which the thermostat temperature is controlled defines

the working principle of the instrument and hence the strategy for evaluation of the corrected temperature rise.

In combustion calorimetric instruments with a high degree of automation, especially in the evaluation of the

results, the calorimeter is in a few cases not as well-defined as the traditional, classical-type calorimeter.

Using such an automated calorimeter is, however, within the scope of this Technical Specification as long as

the basic requirements are met with respect to calibration conditions, comparability between calibration and

waste experiments, ratio of sample mass to bomb volume, oxygen pressure, bomb liquid, reference

temperature of the measurements and repeatability of the results.

Equipment, adequate for determinations of calorific value in accordance with this Technical Specification, is

specified below.
6.2 Calorimeter with thermostat

6.2.1 Combustion bomb, capable of safely withstanding the pressures developed during combustion. The

design shall permit complete recovery of all liquid products. The material of construction shall resist corrosive

acids resulting from the combustion of waste. A suitable internal volume of the bomb would be from 250 ml to

350 ml.

6.2.2 Calorimeter can, made of metal, highly polished on the outside and capable of holding an amount of

water sufficient to completely cover the flat upper surface of the bomb while the water is being stirred.

6.2.3 Stirrer, working at constant speed.

The stirrer shaft should have a low-heat conduction and/or a low-mass section below the cover of the

surrounding thermostat to minimize transmission of heat to or from the system; this is of particular importance

when the stirrer shaft is in direct contact with the stirrer motor.

6.2.4 Thermostat (water jacket), completely surrounding the calorimeter, with an air gap of approximately

10 mm separating calorimeter and thermostat.

The mass of water of a thermostat intended for isothermal operation shall be sufficiently large to outbalance

thermal disturbances from the outside. The temperature should be controlled to within ± 0,1 K or better

throughout the experiment.

6.2.5 Temperature measuring instrument, capable of indicating temperature with a resolution of at least

0,001 K so that temperature intervals of 2 K to 3 K can be determined with a resolution of 0,002 K or better.

The absolute temperature shall be known to the nearest 0,1 K at the reference temperature of the calorimetric

measurements. The temperature measuring device should be linear, or linearized, in its response to changes

in temperature over the interval it is used.

6.3 Crucible, of silica, nickel-chromium, platinum or similar non-reactive material.

The crucible should be 15 mm to 25 mm in diameter, flat based and about 20 mm deep. Silica crucibles

should be about 1,5 mm thick and metal crucibles about 0,5 mm thick. Base metal alloy crucibles are suitable

if after a few preliminary firings the weight does not change significantly between tests.

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6.4 Ancillary pressure equipment
6.4.1 Pressure regulator, to control the filling of the bomb with oxygen.

6.4.2 Pressure gauge, e.g. 0 MPa to 5 MPa, to indicate the pressure in the bomb with a resolution of

0,05 MPa.

6.4.3 Relief valve or bursting disk, operating at 3,5 MPa, and installed in the filling line, to prevent

overfilling the bomb.

CAUTION — Equipment for high-pressure oxygen shall be kept free of oil and grease (high vacuum

grease recommended by the manufacturer can be used according to the operating manual of the

instrument). Do not test or calibrate the pressure gauge with hydrocarbon fluid.
6.5 Timer
6.6 Balances

6.6.1 Balance for weighing the sample, fuse etc., with an accuracy of at least 0,1 mg; 0,01 mg is

preferable and is recommended when the sample mass is of the order of 0,5 g or less.

6.6.2 Balance for weighing the calorimeter water, with an accuracy of at least 0,5 g (unless water can be

dispensed into the calorimeter by volume with the required accuracy).

6.7 Pellet press, capable of applying a force of about 100 kN, either hydraulically or mechanically, and

having a die suitable to press a pellet with a diameter of about 13 mm and a mass of (1 ± 0,1) g.

7 Sample storage

Biologically active laboratory samples should be stored at about 4 °C and the analysis should be carried out

within seven days after sampling. If this is not possible, the samples should be preserved further, for example

by freezing or freeze drying in order to minimize biodegradation and loss of volatile compounds.

8 Sample preparation

The goal of any sample preparation procedure is to prepare a test sample in which the composition is not

significantly changed compared to the laboratory sample. Due to the different properties of the various kinds

of materials there is no general procedure available.
Recommendations for sample pretreatment are given in EN 15002.

Depending on the nature of the sample material a drying step might be required. If necessary, air-dry the

complete sample or dry it in a ventilated drying oven at a temperature not exceeding 40 °C or in a freeze

dryer. The drying time depends on the technique chosen and the type of sample.

For solid waste materials, one or more particle size reduction steps might be needed in order to achieve a

homogeneous and representative test portion. The choice of the technique depends on the nature of the

sample and on the particle size needed. Typically, particle size reduction is a multi-step operation that implies

the use of a sequence of different techniques like crushing, cutting or grinding.

The particle size of the analysis sample material of solid waste samples for the determination of calorific value

shall be less than 1 mm and preferably less than 0,2 mm.

Determination of the moisture content of the resulting analysis sample shall be carried out according to

EN 14346.
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9 Procedure
9.1 General

The calorimetric determination consists of two separate operations under the same specified conditions:

— combustion of the calibrant (benzoic acid);
— combustion of the sample.
The procedure for both operations is essentially the same.

In the calibration experiment, the “effective heat capacity” of the calorimeter is determined (see Clause 10).

Both experiments consist of carrying out quantitatively a combustion reaction (in high-pressure oxygen in the

bomb) to defined products of combustion and of measuring the change in temperature caused by the total

bomb process.

The temperature measurements required for the evaluation of the corrected temperature rise θ are made

during a fore period, a main (= reaction) period, and an after period as outlined in Figure 1. For the adiabatic

type calorimeter, the fore and after periods need, in principle, be only as long as required to establish the

initial (firing) and final temperatures, respectively. For the isoperibol (isothermal jacket) and the static-jacket

type calorimeters, the fore and after periods serve to establish the heat exchange properties of the calorimeter

required to allow proper correction for heat exchange between calorimeter and thermostat during the main

period when combustion takes place. The fore and after periods shall then be longer.

Key
1 fore period initial temperature, in °C
2 main period temperature of the jacket,
in °C
3 after period final temperature, in °C
4 ignition τ time, in min
Figure 1 — Time-temperature curve (isoperibol calorimeter)
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The power of stirring shall be maintained constant throughout experiments that call for a constant rate of

stirring. An excessive rate of stirring results in an undesirable increase in the power of stirring with ensuing

difficulties in keeping it constant. A wobbling stirrer is likely to cause significant short-term variations in stirring

power.

During combustion, the bomb head will become noticeably hotter than other parts of the bomb, and it is

important to have enough well-stirred water above it to maintain reasonably small temperature gradients in the

calorimeter water during the rapid part of the rise in temperature.
9.2 General preparations, measurements and temperature corrections
9.2.1 Preparation of the bomb

Weigh the combustible fuse and/or ignition wire either with a resolution of at least 0,1 mg, or keep its mass

constant, within specified limits, for all experiments (calibration and waste sample experiments). Fasten the

ignition wire tautly between the electrodes in the bomb. Check the resistance of the ignition circuit of the

bomb; for most bombs, it should not exceed 5 Ω to 10 Ω, measured between the outside connectors of the

bomb head, or between the connector for the insulated electrode and the bomb head.

Tie, or attach firmly, the fuse to the ignition wire.

Place the crucible with its content (according to 9.3 or 9.4) in its support and bring the fuse into contact with

the content. Make sure that the position of the crucible in the assembled bomb is symmetrical with respect to

the surrounding bomb wall.

When the ignition wire is combustible as well as electrically conducting, an alternative procedure may be

adopted. A longer piece of wire, enough to make an open loop, is connected to the electrodes. After mounting

of the crucible, the loop is brought in contact with the sample pellet or capsule. (In some cases the ignition

process is better controlled when the wire is kept at a small distance above the sample pellet.) Care should be

taken to prevent any contact between ignition wire and crucible, in particular when a metal crucible is used

since this would result in shorting the ignition circuit. A special fuse is superfluous under these conditions. The

resistance of the ignition circuit of the bomb will be increased by a small amount only. For closer details of

preparing the bomb also refer to the manufacturer's instructions.

Add a defined amount of distilled water to the bomb. The amount shall always be exactly the same in

calibration and in sample experiments. As a main principle (1,0 ± 0,1) ml distilled water is added into the

bomb. For some waste samples (and some calorimeters) the complete combustion can be achieved by

omitting the addition of distilled water to the bomb. In some cases the total absorption of the gaseous

combustion products might require the use of a larger amount of distilled water (e.g. 5 ml).

Assemble the bomb.

Charge the bomb slowly with oxygen to obtain a pressure of (3,0 ± 0,2) MPa. The same procedure shall be

used both in calibration and in sample experiments. If the bomb is inadvertently charged with oxygen above

3,3 MPa, discard the test and begin again.
WARNING — Do not reach over the bomb during charging.
9.2.2 Assembling the calorimeter

Bring the calorimeter water to within ± 0,3 K of the selected initial temperature and fill the calorimeter can with

the required amount. This quantity of water in the calorimeter can shall be the same to within 0,5 g or better in

all experiments.
Place the bomb in the calorimeter can.
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