BS/EN 60079-29-1-2016 pdf download.Explosive atmospheres Part 29-1: Gas detectors — Performance requirements of detectors for flammable gases.
Where an equipment manufacturer makes any claims in the instruction manual regarding any special features of construction or superior performance that exceed these minimum requirements, all such claims shall be verified and the test procedures shall be carried out as stated in each clause and shall be extended or supplemented, where necessary, to verify the claimed performance.
When verifying a manufacturer’s claimed performance or special features of construction, the minimum requirements of the standard shall be met and the manufacturer’s claimed performance shall be verified. Any additional tests shall be agreed upon by the manufacturer and test laboratory and identified and described in the test report.
EXAMPLE When a manufacturer claims a sensor accuracy over a defined temperature range of —50 C to +55 C at ±15 %LFL (assuming a measuring range of 0 to 100 %LFL), the sensor must meet the manufacturer’s claim from
—50 C to —20 C and meet the specified requirements of 5.4.6 for the temperature range of —20 C to +55 C.
There may be applications where equipment with special features are needed. One example may be a gas detector intended to be used in coal mines with a measuring range up to 10 % (v/v) methane but with the accuracy requirements of 5 % (v/v) methane equipment. In such a case it shall be tested like 5 % (vlv) methane equipment.
4.1.2 Equipment ratings
Electrical assemblies and components shall conform to the construction and test requirements
of 42 and Clause 5, where applicable In addition, parts of the flammable gas detection equipment intended for use in hazardous areas shall conform to the Type(s) of Protection as
specified in the appropriate regulations for explosion protection •
The ambient temperature and pressure ranges of equipment conforming to this standard shall not exceed the ambient temperature and pressure ranges of the Type(s) of Protection.
4.2 Construction
4.2.1 General
Gas detection equipment or parts thereof (e.g. remote sensors) specifically Intended for use in the presence of corrosive vapours or gases, or which may produce corrosive by-products as a result of the detection process (e.g. catalytic oxidation or other chemical process) shall be constructed of materials known to be resistant to corrosion by such substances.
All equipment shall be constructed to facilitate regular accuracy checks.
All materials and components used in the construction of the equipment shall be used within the manufacturer’s ratings or limitations, unless otherwise specified by appropriate safety standards.
4.2.2.3 Measuring range
Any over-range measurements shall be clearly indicated as such.
4.2.2.4 Selectable range
If the equipment has more than one measuring range, the range selected shall be clearly identified.
4.2.2.5 Suppression of indication and measured values below zero
It shall be possible to configure the equipment such that in measuring mode any kind of suppression of the measured value is permanently disabled. In calibration mode any kind of suppression of the measured value shall be automatically disabled.
Measured values within the measuring range shall be indicated.
Measured values below 5 % of the measuring range (values below zero included) shall be indicated as:
a) zero,
b) another indication that the measured value is below 5 % of the measuring range or
c) the measured value.
Equipment with a measuring range up to 20 % LFL shall indicate measured values below -10 % of the measuring range or shall provide a fault signal. The equipment shall provide a fault signal at measured values below —20 % of the measuring range at the latest.
All equipment with measuring ranges greater than 20 % LFL shall provide a fault signal at measured values below —10 % of the measuring range at the latest. Portable and transportable equipment shall indicate measured values below —5 % of the measuring range or shall provide a fault signal.
Any suppression of indication shall be explained In the manual (see 4.4 d)).
4.2.2.6 Indicator light
If only one indicator light is provided for signalling alarms, special states and other indications, it shall be coloured red. If separate indicator lights are used or if a multi-coloured indicator light is provided, the colours shall be used in the following order of priority ((a) being highest priority):BS/EN 60079-29-1-2016 pdf download.