maintenance procedures in hazardous areas that will ensure the integrity of the explosion-protection technique, including: the purpose of a maintenance schedule the purpose and extent of ‘close’, ‘sample’ and ‘periodic’ inspections the features of each explosion-protection techniques that should be included in a maintenance schedule the impact of environmental conditions on explosion-protected equipment, including corrosion and frequency of maintenance the documentation requirements for recording the maintenance process and results the use of standards in determining the requirements with which the design of explosion-protected apparatus shall comply techniques for the installation and maintenance of fixed gas detection equipment, including: use of manufacturer instruction manuals; for example, operating instructions, adjustments procedures and operational limitations installation and maintenance of standards and/or codes of practice for gas detection equipment location of fixed sample points or sensors, including: optimal sensing maintainability and ease of calibration protection against environmental and mechanical damage gas and vapour releases, including: the nature of a site natural and mechanical ventilation common problems with fixed gas detectors calibration and response checking factors to consider in the evaluation and selection of portable and fixed gas detection equipment, including: requirements for gas detection for a given situation, including: sources for obtaining data on physical chemistry of the gas to be detected sources for obtaining data on the conditions under which the gas may be present processes of assessing the specifications of gas detection equipment against established requirements detecting gases and vapours, including: apparatus capability and users’ knowledge propagation of gases - release of gas and vapours, ventilation, density, and temperature and location gases to be detected and not to be detected intended application environmental effects safety when monitoring for flammable gases where personnel could be present common properties of gases and vapours - density of gases, vapours and their mixtures; effect of temperature on density; lower explosive limit (LEL) and upper explosive limit (UEL) of combustibles and toxicity the differences between detecting gases and vapours - added complication of evaporation, condensation and temperature effects of vapours and their effect on propagation, calibration and detection, including sampling oxygen deficiency and effects on safety, including: chemical reaction of oxygen with solid products chemical reaction of oxygen with gaseous products dilution of the air by displacement by some other gas or vapour measuring principles of catalytic sensors, electrochemical sensors, infrared sensors and semi-conductor sensors, including: common applications limitations and safety interferences of other gases with the measurement poisoning of the sensor measuring principles of thermal conductivity sensors, flame ionisation, detectors (FID), flame temperature analysers (FTA), photo ionisation detectors (PID) and paramagnetic oxygen detectors selection of apparatus, including: environment system response delay gas to be detected with respect to measurement principles behaviour of gas and vapour releases, including: rate of release density temperature/pressure design and installation, including: sensor, sampling or open path location site environmental conditions (adverse weather, excess temperature, vibration and other mechanical interference, hosing, airborne contaminants and corrosion) integrity and safety, including: redundancy protection against loss of power supply commissioning and scheduled maintenance, including: sample lines diffusion sensor screens initial gas calibration adjustment of alarm set points plans and records. |