How to set-up your CalCard


To set up your CalCard correctly requires only a few simple steps:

  1. Place one probe on either of the two pads on the outside of the card labelled "Common"
  2. Place the other probe onto each range and jot down the readings


As soon as you get your CalCard you need record the baseline measurements. You should do this as soon as your test equipment has been calibrated to ensure your readings are the most accuracte they can be. Following the two steps above, make a note of each reading.

On the rear of the card is a peel away laminate cover. Carefully peel this back about half way. Then using a fine-tip, felt-pen, write down your readings into each corrisponding box. Return the peeled laminate back down over the results, covering and protecting them. Your CalCard is now ready to use with reliable baseline readings protected on the back.

ISS Cal Card Instructions



About The CalCard:

The CalCard verification unit utilises a specific fixed range of resistance values through which the ongoing accuracy and operation of test instruments between calibration periods can be verified:

  • Ensure that an instrument's measurement ability does not wander or drift over a determined period
  • Functions as a simple check measurement to dispel any doubts an electrician may have about meter readings. This verification is particularly useful when carrying out on-site testing
ISS calibrate all major brands of test equipment to current industry standards in our own laboratories, giving unequalled turnaround times and very competitive prices.

Note: The CalCard is not designed for RCD or Zs tests.

The primary thing to remember when using your CalCard is the importance of accuracte baseline results. Your baseline results should only be obtained by newly calibrated instruments or from a brand new tester with a manufacturers certificate.

It is also important to remember that is is not the absolute resistance measurements from your baseline results that are being monitored, but the relative measurements. Your baseline results should stay the same.

If your results start to differ from your CalCard (more than 10%) then it is recommended you send your instrument back for re-calibration. You can find out how to return your instrument for calibration here: