PPM Test products can be used in markets across Test and Instrumentation industries including aircraft Electromagnetic Compatibility (EMC) testing and certification, military standard testing, high and ultra-high voltage testing and directed energy testing.
The products are predominantly aimed at testing markets needing a highly shielded fibre optic link for use in EMC immunity testing scenarios. EMC immunity testing can often be categorised in two broad camps; continuous wave signal immunity testing (a frequency domain test) and pulse signal test (a time domain test).
Aircraft EMC Testing and Certification
EMC testing includes:
- High Intensity Radiated Field (HIRF) testing
- Low-Level Swept Field (LLSF) tests
- Low-Level Swept Current (LLSC) tests
- Lightning testing.
Fibre optic links are essential for Aircraft EMC testing, as they:
- prevent the testing instrumentation from influencing the aircraft transfer impedance
- significantly reduce signal loss
- have a significant increase in measurement dynamic range, particularly at higher frequencies
- provide full galvanic isolation between the probe and the test instrument.
PPM Test’s fibre optic links mean measurements can be taken in the most inaccessible places on aircraft and other vehicles. When combined with the Prodyn EM instrumentation products – including electric field and magnetic field sensors, current probes and baluns – a measurement system for extreme EM conditions can be implemented with ease.
Military Standard (MIL-STD) Testing
MIL-STD EMC testing is typically performed at higher immunity levels than commercial product testing designed for domestic or light industrial use. Military standards are developed and issued by the USA Department of Defense (DoD) and are commonly used globally as a testing benchmark. Other nations often have equivalent specifications which use common requirements to MIL-STD.
Two common MIL-STD specifications include:
- MIL-STD 461: general EMC standard for equipment and sub-systems
- MIL-STD 188-125: effectiveness of ground based facilities against High-altitude Electromagnetic Pulses (HEMP).
Both MIL-STDs include continuous wave and high energy EMP tests, and call up the use of fibre optic links to connect test probes through to the test instrumentation. The links provide a galvanic-free and pick-up-free connection.
For a MIL-STD 461 RS105 (radiated susceptibility, transient EM field) example, a typical test system could include:
- free space or ground plane field sensors, often referred to as D-dot sensors (1 GHz minimum bandwidth)
- balun to connect balanced signal from D-dot probe, through to single ended signal required by shielded link and remote instrumentation
- shielded fibre optic link (1 GHz minimum bandwidth).
High and Ultra-High Voltage
PPM Test products can provide safe measurement and testing in a high voltage (HV) environment for the analysis of switching transients and their effects, as well as HV sensing and power applications.
Fibre optic links can be used to provide galvanic isolation in these tests for accurate measurements.
Directed Energy Testing
Directed energy testing and Intentional Electromagnetic Interference (IEMI) can be generated in a number of different threat formats, such as high power electromagnetics in various radiated bands or high power pulse discharge (for example from high energy capacitor banks).
Just like the other market areas, fibre optic links can be used to provide galvanic isolation from the test probes to the test instrumentation, providing an accurate link for measurements and improving test system reliability.
To find out more about PPM Test products and markets, please contact us.
