I am currently working with an ECG cable, is there a way for me to test the integrity of the shielding of the cable without using it directly on an ECG monitor to check for interference.

  • \$\begingroup\$ Are you testing for assembly faults, or for cable suitability? \$\endgroup\$ – Jack B Oct 23 '18 at 14:47
  • \$\begingroup\$ for cable suitability \$\endgroup\$ – msa12 Oct 23 '18 at 14:50
  • \$\begingroup\$ It would be good to edit that into your question, as comments may vanish at any time. I'm afraid I don't have an answer, I suspect there is no easier way. But maybe someone else will come along. \$\endgroup\$ – Jack B Oct 23 '18 at 14:58
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    \$\begingroup\$ There are several ways to test cable shielding effectiveness, but to be relevant they should apply to your equipment's needs, otherwise you may be wasting your time running inapplicable tests, or worse miss something because of test methodology. Does the monitor have any sort of specification on the "standard" cable itself? To give you an idea, for low frequency you typically have the 50/60Hz line noise, which shielding really doesn't do much to get rid of in an ECG situation (unless you put the patient into a Faraday cage), you have to do a differential signal measurements. \$\endgroup\$ – isdi Oct 23 '18 at 17:31
  • \$\begingroup\$ On the other hand the input circuitry may be sensitive to high frequency RF signals (to some extent), but without knowing the range and reference cable performance spec you have no idea what specifications your cable needs to meet. That said you can search for cable shield reduction factor and transfer impedance for some of the techniques used (aside from anechoic chambers with RF signal generators etc. $$$ and difficulty in getting numbers that are accurate on the latter. \$\endgroup\$ – isdi Oct 23 '18 at 17:34

Cable shielding depends on the % coverage by the woven braid with its gaps. Thus a solid shield (aluminum? foil) with a contact wire is the better type of coax cable.

For excellent control of electric fields, the external fields must NOT be able to find a path to the center-conductor. Hence the need for a solid(foil)shield, not a woven shield.

All this will get you some Electric Field shielding.

Magnetic fields are a different matter.


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