Flammability testing instrumentation

Some instrumentation available from ATS FAAR for flammability testing of polymers is listed in Table 17.1. Other suppliers are listed in Appendix 1. 

Intrinsic Safety. Static electrical concepts such as minimum ignition energy do not directly apply when assessing the safety of electrical circuits such as radios, flashlights and instrumentation. Intrinsically safe electrical equipment is usually available which has been subjected to fault analysis and testing. The equipment must be certified for the flammable atmosphere in which it will be used (NFPA 497). Refer to texts on Intrinsic Safety such as [63],... 

A multi-disciplined team interviewed witnesses and performed tests, and the evidence was followed to a sound conclusion. Investigators sent the explosion meters (flammable gas detectors) to the instrument shop for examination. The welding torch was also inspected. Experts found both the torch and the meter behaved satisfactorily. There was speculation that some aquatic life deteriorated and formed methane, but that was not the case. They concluded that the fuel was dissolved methane from the well water system that was routed to the pump seal. Trace amounts of dissolved methane (about 0.02 percent by volume) accumulated in the well water stream flowing through the 3/8-inch-diameter stream on the... 

Class 1 safety instrumentation loops include alarms and trips on storage tanks containing flammable or toxic liquids, devices to control high temperature and high pressure on exothermic-reaction vessels, and control mechanisms for low-flow, high-temperature fluids on fired heaters. Other Class 1 instruments include alarms that warn of flame failure on fired heaters, and vapor detectors for emergency valve isolation and sprinkler-system activation. All of these alarms, shutdown valves, and other critical instruments are regularly proof-tested to a well-defined schedule. 

Combustion may also occur in mixed-phase systems (solids with liquids, solids with gases, liquids with gases). The theory of mixed-phase combustion is a much less studied subject, and consequently flammability data are almost exclusively determined by experimental testing. The primary hazard with most oxidant delivery systems is that of mixed-phase combustion the oxidant is a gaseous material which may support combustion of the system which is either a liquid (oils, greases, coolants) or a solid (piping, valves, instruments). 

Before an employee enters a confined space, you shordd test the air with a calibrated direct-reading instrument for (1) oxygen content, (2) flammable gases and vapors, and (3) potential toxic air contaminants. 

If using several individual instruments, are they testing in the right sequence (oxygen, flammables, toxics) ... 

Table 17.1 Instrumentation available from ATS FAAR for testing flammability properties of polymers ...

Before an employee enters the space, the internal atmosphere shall be tested by a trained employee using a calibrated direct-reading instrument. The atmosphere should be tested for oxygen content, for flammable gases and vapors, and for potential toxic air contaminants, in that order. Any employee who enters the space, or that employee s authorized representative, shall be provided an opportunity to observe the pre-entry testing required by this paragraph. The atmosphere within the space shall be periodically tested as necessary to ensure that the continuous forced air ventilation is preventing the accumulation of a hazardous atmosphere. 

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