Simulators
more thorough “in-between calibration cycle” check of the ESD simulator’s output waveform is something every EMC engineer and technician should consider.
The regular use of a current sensing transducer and high-bandwidth oscilloscope and an ESD gun in-house calibration check process will alleviate much of this anguish.
All the IEC 61000-4-2 ESD output waveform points should be verified on a regular basis. You will have to perform your own risk analysis to determine how often this check is performed given your unique situation. If you performed the check before and after each test and included the before/after waveforms in a test report, you could easily prove the product was ESD tested correctly should proper testing ever be questioned.
The different output waveforms produced by some guns can be “dirtier” in the areas not specified by the standard, than other “cleaner” guns. The “dirty” ESD guns output more aggressive, wider bandwidth signals that some equipment might be susceptible to when tested for compliance. This equipment will fail the compliance test and need re-design to pass. If this same equipment is tested with a “clean” gun, it might pass.
Some equipment suppliers elect to test their equipment with ESD guns outputting the more aggressive waveform, thinking that their product will be more robust to real-life ESD events that may occur in actual usage. Testing products with a “clean” gun is for “sissies.” Depending on who you talk too, testing with a “dirty” gun may be a misguided effort.
The other side of the camp wants the ESD gun to output the cleanest waveform possible, and each gun they use to be the same. This side of the camp is interested in greater test repeatability and less uncertainty.
Adding your own in-house capability to check your ESD gun’s output waveform will enable you to determine if you either have a “clean” or “dirty” ESD gun so that you can then take appropriate action.
- ESD Guns / The EMC Shop. Waveform Verification for IEC 61000-4-2 Waveshape. Retrieved from https://www.esdguns.com/content/11-waveform-verification-iec-61000-4-2-waveshape
- In Compliance Magazine. (2018, February 5). What Every Electronics Engineer Needs to Know About: ESD Simulators. Retrieved from https://incompliancemag.com/article/esd-simulators
- IEC 61000-4-2:2009. Electromagnetic compatibility (EMC) – Part 4-2: Testing and measurement techniques – Electrostatic discharge immunity test