GB/T 43905.3-2024Laboratory method for sampling fume and gases in welding and allied processes - Part 3: Determination of ozone emission rate during arc welding (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting:

This document is part 3 of GB/T 43905 "Laboratory methods for sampling of fumes and gases during welding and allied processes":

The following parts have been published:

--- Part 1: Determination of fume emission rate during arc welding and collection of fume for analysis;

--- Part 2: Determination of emission rates of carbon monoxide, carbon dioxide, nitric oxide and nitrogen dioxide during arc welding, cutting and gouging;

--- Part 3: Determination of ozone emission rate during arc welding;

--- Part 4: Emission limits of welding fume from welding materials;

--- Part 5: Identification of thermal degradation products of organic materials during welding or cutting based on pyrolysis-gas chromatography-mass spectrometry;

--- Part 6: Quantitative determination of smoke and gases during resistance spot welding:

This document is modified from ISO 15011-3:2009 "Health and safety for welding and allied processes - Laboratory procedures for sampling fumes and gases":

Method for determination of ozone emission rate during arc welding:

The technical differences between this document and ISO 15011-3:2009 and their reasons are as follows:

--- Replaced ISO/T R25901 (see Chapter 3) with the normative reference GB/T 3375 to apply my country's technical requirements;

--- Added the term and definition of "emission rate" (see 3.3) to facilitate the implementation of this document;

--- The contents of "Note" in 5:1 are moved to the main text to apply my country's technical requirements;

--- Deleted the relevant requirements for equipment calibration (see 5.3, 5:5, 5:6, 5:7 and 5:8) to conform to the actual situation in my country;

--- Added the description of welding method types (see 6.1) to clarify the applicable welding method types to facilitate the implementation of this document;

--- The normative reference GB/T 27418 replaces ISO/IEC Guide 98-3 (see Chapter 7) to apply my country's technical requirements:

The following editorial changes were made to this document:

--- According to the content and scope of application of the standard, the name of the standard is changed to "Laboratory Methods for Sampling Fumes and Gases in Welding and Related Processes" Method Part 3: Determination of ozone emission rate during arc welding";

--- Part of the content in 3:2 definition is moved to Note 1, and the expression form of test chamber classification is changed;

--- Deleted the "Notes" in 5:5 and C:1 of ISO 15011-3:2009;

---5:7, 5:9, 5:10, 6:3, 6:4 use itemized expressions;

--- Replaced ISO 6947 with the informative reference GB/T 16672 (see B:1):

Introduction

GB/T 43905 "Laboratory methods for sampling of fumes and gases during welding and allied processes" provides laboratory methods for sampling and analysis of fumes and gases:

GB/T 43905 is a universal standard for the analysis of dust and gas generated by different process methods:

The basic method standard consists of six parts:

--- Part 1: Determination of smoke emission rate during arc welding and collection of smoke for analysis: The purpose is to specify the conditions applicable to welding that is prone to generate smoke:

Laboratory method for determination of welding fume emission rate from open arc welding of fumes and collection methods for analysis:

--- Part 2: Determination of emission rates of carbon monoxide, carbon dioxide, nitric oxide and nitrogen dioxide during arc welding, cutting and gouging:

The purpose is to specify the carbon monoxide, carbon dioxide, nitrogen monoxide, and carbon dioxide generated during arc welding, cutting, and gouging:

Laboratory method for determination of nitrogen emission rate:

--- Part 3: Determination of ozone emission rate during arc welding: The purpose is to specify the ozone emission rate applicable to automatic arc welding process Laboratory method for determination of emission rates:

--- Part 4: Limits of welding fume emissions from welding materials: The purpose is to specify the limits applicable to non-alloy steel, alloy steel and non-ferrous metals:

Method for compiling welding fume emission limits for all welding materials used for manual, semi-automatic or fully automatic arc welding connections or cladding:

--- Part 5: Identification of thermal degradation products of organic materials during welding or cutting based on pyrolysis-gas chromatography-mass spectrometry:

The regulations apply to coatings composed wholly or partly of organic materials that are subjected to thermal degradation during welding, cutting, preheating and straightening:

Laboratory method for identification and semi-quantitative measurement of the components of undefined products:

--- Part 6: Quantitative determination of smoke and gases in resistance spot welding: The purpose is to specify the application of the resistance spot welding of coated and uncoated steel sheets:

Laboratory method for determination of emission rates of fumes and gases generated by welding:

Welding and related processes generate fumes and gases which are harmful to human health if inhaled:

The information can help occupational health professionals assess worker exposure and determine appropriate control measures:

The absolute exposure concentration depends on factors such as the position of the welder relative to the fume and airflow and cannot be predicted from emission rate data:

Generally speaking, under the same operating conditions, a higher emission rate is expected to have a higher exposure concentration, and a lower emission rate is expected to have a lower exposure concentration:

Therefore, the emission rate data can be used to predict the relative changes in exposure that may occur in the workplace under different welding conditions and to it is used to determine measures to reduce such exposure but cannot be used to calculate ventilation requirements:

This document specifies a laboratory method for determining the ozone emission rate in a fume hood during arc welding:

The simple rules allow the user to select test parameters so that the impact of different variables can be evaluated:

The results of measuring ozone emission rate using this method may vary due to changes in environmental conditions:

This document can be used to evaluate the effects of welding wire, welding parameters, process, shielding gas, specimen composition and specimen surface condition on ozone emission rate:

Impact:

The execution of this document and the interpretation of the results obtained are the responsibility of qualified and experienced personnel:

Sampling of fumes and gases during welding and related processes Laboratory methods - Part 3: Ozone in arc welding Determination of emission rate

1 Scope

This document describes a laboratory method for determining the ozone emission rate during arc welding and specifies the apparatus, materials, test procedures, data and procedures:

According to processing and test reports:

This document applies to gas shielded arc welding and other processes that can be automatically welded under a fume hood, such as flux-cored self-shielded arc welding:

Laboratory method for determining the emission rate of ozone generated during the process:

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document:

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document:

GB/T 3375 Welding terminology GB/T 27418 Evaluation and Expression of Uncertainty in Measurement (GB/T 27418-2017, ISO/IEC Guide 98-3:2008, MOD)

3 Terms and definitions

The terms and definitions defined in GB/T 3375 and the following apply to this document:

Soap film flow meter bubble flow meter A basic meter that measures the gas flow rate by measuring the start and end times of the gas pushing a soap film through a calibrated volume in the riser:

Test chamber A semi-enclosed chamber that can be continuously pumped for emission rate testing:

Note 1: Commonly used during arc welding, cutting or gouging operations:

Note 2: Test chambers are generally divided into three categories: test chambers without bottom plates are called "smoke hoods"; test chambers with bottom plates are called "smoke boxes"; and test chambers with bottom plates that are easily and flexibly disassembled are called "smoke boxes":

It can be converted into a "fume hood" or "fume box" according to the needs of use:

Emission rate the mass of smoke or volume of gas emitted per unit time during welding, cutting, gouging and other related processes:

4 Principle

Automatic arc welding is performed on test pieces in a semi-enclosed fume hood test chamber with continuous extraction:

The ozone concentration at the sampling location (mL/m3) and the air flow rate through the fume hood (m3/min):

The ozone emission rate (mL/min) is calculated from the flow rate: