EMCL-20/-35 EM Coupling Clamp

For immunity tests acc. to IEC/EN 61000-4-6 Ed. 4.0

Cable diameter up to 20 mm / 37 mm, 10 kHz – 1000 MHz

Technical specification   
Type EMCL-20 EMCL-35
Frequency range 10 kHz – 1000 MHz
Nominal impedance 50 Ohm
Connector N-type female
Maximum input level:
0.15 – 100 MHz 100 W, 15 min.
100 – 230 MHz 100 W, 5 min
230 – 1000 MHz 50 W, 3 min
Cable diameter < 20 mm  < 37 mm
Weight 7 kg 14 kg
Dimensions (W x H x D) 632 x 120 x 80 mm 666 x 135 x 120 mm
Optional available Matching network for EM coupling clamp type EMCL type EMCL-MN10k
Matching Transformer for BCI probe for CS114 type CS114-MN10k
Calibration unit type KAL-EMCL includes:
– mounting bracket incl. 2 pcs. 150 to 50 Ohm adapter
– 1 pc. calibration cable
– 1 pc. 50 Ohm- termination (N)
– 1 pc. adapter BNC(f)-N(m)

According to IEC/EN 61000-4-6 the preferred coupling and decoupling devices are the CDNs, for reasons of test reproducibility and protection of the AE. However, if they are not suitable or available, clamp injection should be used.
Often, clamp injection needs to be applied to multi-pair balanced cables because suitable CDNs might not be available.
The EM clamp establishes both capacitive and  inductive coupling to the cable connected to the EUT. The EM clamp (in contrast to the conventional current injection clamp) has a directivity ≥ 10 dB, above 10 MHz, so that a defined impedance between the common-mode point of the AE and the ground reference plane is no longer required. Above 10 MHz, the behaviour of the EM clamp is similar to that of a CDN.

– EM clamp for immunity testing of cables with up to 20/37mm diameter
– High coupling factor: less than 15W (EMCL-20)/18 watts (EMCL-35) amplifier output power is required to obtain a test level of 10 V
– Calibration unit and calibration data are supplied with each instrument

The EM Clamp was developed for test frequencies above 150 kHz. For product standards having requirements in the frequency range from 10 kHz – 150 kHz the clamp cannot be used as usual with the 6 dB attenuator, because the insertion loss is to high for an effective coupling. A matching network has to be used, transforming the clamps low impedance to a reasonable value for the amplifier. With this matching network tests up to 10 V with 80% AM can be performed savely and repeatable.



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