A new, electronic method for intrinsic safety testing

Intrinsic safety testing is a method for ensuring that electrical apparatus designed to be used in explosive environments will not provide enough energy to cause an explosion. Under the current international standard an apparatus that is being tested for intrinsic safety is connected to a test device called "Spark Test Apparatus" (STA). The STA makes and breaks a short circuit fault condition inside an explosive gaseous chamber, and the device under test produces the energy for the electrical discharges inside the explosive environment. If an explosion does not occur during the test then the apparatus is considered to be safo for use in explosive environments. This is a stochastic testing process which has proven to be unreliable; therefore there is a need to develop a better method. A novel concept called the Electrical Spark Tester (EST) is being developed by CRC Mining in collaboration with German metrology institute Physikalisch-Technische Bundesanstalt, as an alternative spark test apparatus. The proposed method utilizes a semiconductor device to emulate the electrical characteristics of a spark phenomenon. The apparatus under test will be connected to the EST, and through a series of tests the results from a simulated spark will determine the risk of an explosion occurring. This paper presents work to date on the development of the EST