GB 12358-2024 Gas detection and alarm instruments for workplace - General technical requirements
1 Scope
This document defines the terms for gas detection and alarm instruments for workplaces, provides classification of these instruments, specifies their technical requirements, inspection rules, packaging, transportation and storage, marking, instructions for use, and use requirements, and also describes test methods.
This document is applicable to the production and use of detection and alarm instruments for flammable gases, toxic gases, and oxygen in workplaces.
Note 1: Gas detection and alarm instruments (hereinafter referred to as "instruments") include gas detectors, gas alarms, and gas detectors and alarms.
Note 2: For gas detection and alarm instruments used in other places, if there is no otherwise requirement stipulated by relevant standards, this document may serve as a reference
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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.
GB/T 3836.1 Explosive atmospheres - Part 1: Equipment - General requirements
GB/T 4857.5 Packaging - Transport packages - Vertical impact test method by dropping
GB 8958 Safety regulation for working under hazardous condition of the oxygen deficiency
GB/T 17626.2 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.3 Electromagnetic compatibility - Testing and measurement techniques - Part 3: Radiated, radio-frequency, electromagnetic field immunity test
GB/T 17626.4 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6 Electromagnetic compatibility - Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
GB/T 20438.1 Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 1: General requirements
GB/T 20438.2 Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 2: Requirements for electrical/electronic/programmable electronic safety-related systems
GB/T 20438.3 Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 3: Software requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
workplace
all places where workers conduct occupational activities
3.2
detection parts
component that converts the concentration of flammable gas, toxic gas, or oxygen into an electrical signal
3.3
alarm parts
component that alerts personnel on-site and in the vicinity through sound, light, or vibration
3.4
indicator parts
component that indicates the measured values of gas concentrations
3.5
gas detectors
assembly that detects gas concentrations by detection parts, and indicates gas concentration values by indicator parts
3.6
gas alarms
instrument that detects gas concentrations by detection parts, and triggers alarm signals by alarm parts when they reach the corresponding alarm set points
3.7
gas detectors and alarms
instrument that detects gas concentrations by detection parts, indicates gas concentration values by indicator parts, and triggers alarm signals by alarm parts when they reach the corresponding alarm set points
3.8
portable instrument
gas detection and alarm instrument that can be carried/worn by personnel and operated with its own power supply
3.9
fixed instrument
gas detection and alarm instrument fixed in a specific location
3.10
aspirated instrument
instrument with getter pump
gas detection and alarm instrument where the detected gas is driven to the detection parts by the instrument's own power
3.11
diffusion instrument
gas detection and alarm instrument where the detected gas diffuses to the detection parts under the condition that the instrument itself has no power
3.12
contact instrument
gas detection and alarm instrument that can detect gas concentration only when the detected gas is in physical contact with the detection parts
3.13
contactless instrument
gas detection and alarm instrument that can detect gas concentration without the detected gas being in physical contact with the detection parts
3.14
upper measurement limit
maximum concentration value of the detected gas that the detection parts can detect
3.15
minimum response value
minimum concentration value of the detected gas that the detection parts can detect when the instrument is in a stable state under the specified use conditions
3.16
resolution of a displaying device
minimum interval between two adjacent displayed indications that a gas detector and alarm/gas detector can effectively distinguish
3.17
indication error
difference between the arithmetic mean of the instrument's indications and the standard value when the standard gas is introduced into the gas detectors and alarms/gas detectors under test conditions
Note: The percentage obtained by dividing the difference between the arithmetic mean of the instrument's indications and the standard value by the concentration value of the standard gas is the indication error (relative to standard value), which shall be calculated using Equation (1); the percentage obtained by dividing the difference between the arithmetic mean of the instrument's indications and the standard value by the full scale of the instrument is the indication error (relative to full scale), which shall be calculated using Equation (2).
3.18
alarm error
difference between the alarm operation value and the alarm set point when the standard gas is introduced into the gas detectors and alarms/gas alarms under test conditions
3.19
instrument drift
changes in indications over a period of time due to changes in the instrument's measurement characteristics
Note: Instrument drift includes zero drift and span drift.
3.20
repeatability
degree of consistency among the indications obtained from repeated measurements of the same detected gas using the same instrument under the same conditions within a short period of time, expressed as the relative standard deviation
3.21
indication response time
time from the introduction of the detected gas until the gas detectors and alarms/gas detectors reach 90% of their respective stable indications under test conditions
3.22
alarm response time
time from the introduction of the detected gas until the gas detectors and alarms/gas alarms trigger an alarm signal under test conditions
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Technical requirements
6 Test methods
7 Inspection rules
8 Packaging, transportation and storage
9 Marking
10 Instructions for use
11 Use requirements
Annex A (Informative) Test items
Annex B (Informative) Contact instrument test and method
Annex C (Informative) Contactless instrument test and method
Annex D (Informative) Steam interference test method
Bibliography
