MIL-STD-461 CS115 and CS116 are among the most often performed conducted susceptibility tests on defence equipment and subsystems. Both current test signal types are applied to interconnection cables with a coupler, monitoring the amplitude during the test.

How to perform CS115 test?

After making sure that required equipment is available, the test system must be calibrated and data included in the test report. A connection diagram of calibration setup for CS115 with EMC PARTNER MIL-MG3 is provided below.

The coupler CN-BT6 is placed in the calibration jig VERI-MIL3. The 50 Ω load, high voltage attenuator and the attenuators for oscilloscope, as well as the connection cables, are included in VERI-MIL3’s scope of delivery. After performing the calibration, the test setup connections can be performed as shown in the diagram below. EMC PARTNER offers a probe with flat frequency response up to 400 MHz, that can be utilized for monitoring the CS115 fast rise time ( < 2 ns).

With the help of TEMA3000 software, automatic screen dumps of the monitored impulses can be included in the test report. However, the user should conceptualize how the screen dumps are communicated by the oscilloscope to computer/software, as most of the oscilloscopes available on the market cannot send more than 1 screen dump per second over the Ethernet port. One possibility is to acquire all waveforms on one screen dump (some functions allow to superpose measurements over a longer period of time at high repetition rates) or take sample screen dumps from time to time. Both options have advantages and disadvantages.

How to perform CS116 test?

For CS116, the same coupler CN-BT6 and calibration accessories can be used. A calibration setup for CS116 is presented below.

Suitable connection cables are provided also for CS116 test and calibration setups. After calibration and recording of waveforms, the connections for test setup can be performed.

If only CS116 test is performed (no CS115 test) a high bandwidth probe without a flat frequency response can be alternatively used, since the damped sinusoidal transients applied has a relatively narrow frequency bandwidth. However, any probe that is suitable for CS115 can also be used for CS116.

Test equipment

Since the beginning of 2020, EMC PARTNER has been offering its third generation test system based on the modular MIL-MG3 generator. This family of generators has proven to be very reliable, with a relatively reduced need for repairs during previous decade.

• MIL-MG3 has a slot in which plugins can be easily inserted. At the moment, plugins are available for following requirements from standards:
• MIL-STD-461G CS115: Conducted susceptibility, bulk cable injection, impulse excitation.
• MIL-STD-461G CS116: conducted susceptibility, damped sinusoidal transients, cables and power leads. Besides the standard frequencies, any frequency between 10 kHz and 30 MHz is now optionally available with MIL-MG3.