Electronic spark tester available for testing
Since a high profile incident in 1998, where two widely deployed IS certified power supplies failed an intrinsic safety retest (Bell & Hookham, 1999), the Australian Coal Association Research Program (ACARP) has funded numerous research projects investigating options for improving IS certification and testing procedures – especially with a view to replacing or supplementing the IEC 60079.11 Annex B Spark Test Apparatus for intrinsically safe circuits.
Since 2011, Mining3, in collaboration with the German Metrology Institute Physikalisch-Technische Bundesanstalt (PTB), has undertaken a research project to develop the Electronic Spark Test (EST) Apparatus which does away with the mechanical spark contacts and hazardous explosions of the STA. The first phase of the research was completed in 2013, the second in 2015 and the third is now complete.
The Electronic Spark Tester (EST) Apparatus requires neither the creation of real sparks or explosions and instead, measures the voltage and current (VI) response of an IS certified power supply to an electronically simulated break spark event at its output terminals. This method of testing has many significant advantages over the current STA standard, including but not limited to:
- Greater reliability
- A proportional measure of safety
- Feedback of test results
- A test procedure which does not require hazardous substances such as cadmium and gases
Benefits to the IS testing industry includes:
- Power supply designers and manufacturers: More informative test feedback and the possibility of testing power supplies before IS certification and testing is conducted.
- Testing agencies: Reduced risk to test personnel and a greater certainty and repeatability in test results.
- End user: The possibility of on-site or pre-installation testing of IS power supplies to ensure continued compliance of the power supply to the IEC 60079 standard.
While a physical device for the EST apparatus has been developed, it is the first iteration of a final product that can support the industry in the testing to IEC 60079-11 standard. Further development and changes will be required to enhance the usability and functionality of the device.
The hardware platform has been designed with enough flexibility to allow for changes in the way the device measures and applies waveforms. Any changes in the research that affect the way the EST works can be implemented into the current device without re-develop of a new platform.
The software also follows this methodology in that it is script based and can be modified in the future if the research requires modification.
An important factor now for the EST apparatus and methodology is to gain industry acceptance and support of both the device and the research. Demonstrations to test houses, manufacturers and design houses are planned over the next 12 months to show the value of the device being included in the 60079 standards to the IEC Council.
If you have any enquiries or would like to book a demonstration, please contact Enver Bajram, Project Leader at Mining3 – email@example.com.