BS IEC 62990-1:2019 pdf download – Workplace atmospheres Part 1: Gas detectors — Performance requirements of detectors for toxic gases.
This part of ISO/IEC 62990 specifies general requirements for design, function and performance, and describes the test methods that apply to portable, transportable, and fixed equipment for the detection and concentration measurement of toxic gases and vapours in workplace atmospheres and other industrial and commercial applications. This document is applicable to continuously sensing equipment whose primary purpose is to provide an indication, alarm and/or other output function the purpose of which is to indicate the presence of a toxic gas or vapour in the atmosphere and in some cases to initiate automatic or manual protective action(s). It is applicable to equipment in which the sensor generates an electrical signal when gas is present. This document applies to two types of equipment: • Type HM (Health Monitoring) ‘occupational exposure’ equipment: For occupational exposure measurement, the performance requirements are focused on uncertainty of measurement of gas concentrations in the region of Occupational Exposure Limit Values (OELV). The upper limit of measurement will be defined by the manufacturer in accordance with 4.2.1 . • Type SM (Safety Monitoring) ‘general gas detection’ equipment: For general gas detection applications (e.g. safety warning, leak detection), the performance requirements are focused on alarm signalling. The upper limit of measurement will be defined by the manufacturer according to the intended use of the equipment . In general, the requirements for accuracy will be higher for Type HM equipment than for Type SM equipment. The same equipment may meet the requirements of both Type HM and Type SM. For equipment used for sensing the presence of multiple gases this document applies only to the detection of toxic gas or vapour.
2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal) IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements IEC 60529, Degrees of protection provided by enclosures (IP Code) IEC 61 000-4-29, Electromagnetic compatibility (EMC) – Part 4-29: Testing and measurement techniques – Voltage dips, short interruptions and voltage variations on d.c. input power port immunity tests IEC 61 000-6-3, Electromagnetic compatibility (EMC) – Part 6-3: Generic standards – Emission standard for residential, commercial and light-industrial environments IEC 61 000-6-4, Electromagnetic compatibility (EMC) – Part 6-4: Generic standards – Emission standard for industrial environments IEC 61 326-1 , Electrical equipment for measurement, control and laboratory use – EMC requirements – Part 1: General requirements 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp
3.1.5 poisons <for sensing elements> substances that lead to temporary or permanent change of performance, particularly loss of sensitivity of the sensing element 3.1.6 toxic gas gas or vapour that can be harmful to human health and/or the performance of persons due to its physical or physico-chemical properties Note 1 to entry: For the purpose of this document, the term “toxic gas” includes “toxic vapours”. 3.1.7 volume fraction quotient of the volume of a specified component and the sum of the volumes of all components of a gas mixture before mixing, all volumes referring to the pressure and the temperature of the gas mixture Note 1 to entry: The volume fraction and volume concentration take the same value if, at the same state conditions, the sum of the component volumes before mixing and the volume of the mixture are equal. However, because the mixing of two or more gases at the same state conditions is usually accompanied by a slight contraction or, less frequently, a slight expansion, this is not generally the case. 3.1.8 zero gas gas recommended by the manufacturer, which is free of toxic gases and interfering and contaminating substances, the purpose of which is calibration or adjustment of the equipment zero 3.1.9 standard test gas test gas with a composition specified for each item of equipment and gas and/or vapour to be used for all tests unless otherwise stated 3.1 .1 0 time-weighted average concentration TWA concentration concentration of gas in air averaged over a reference period