The CalCard (Calibration Checkbox) Specification

Fulfils the ongoing accuracy requirements, specified by Institution of Engineering & Technology (IET).
Accepted and recommended by all regulatory bodies including NICEIC, ECA, NAPIT and ELECSA.
Multiple industry award-winning.
Smallest, most cost effective and versatile resistance checkbox available.
Used by over 200,000 Electrical professionals.

Extended Calibration

Inspectorates have stated, that providing records are kept of ongoing accuracy and the instrument drift remains within 10% then the instruments calibration period can be extended from 1 year to 3 years.

Records can be kept in three ways: –

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To ensure instrument probes connect consistently the access pads are coated firstly in copper for connectivity, then nickel to prevent hard points of the probe penetrating and breaking the pads, then finally gold to maintain the consistent measurement and protection from corrosion and tarnishing.

  • Top layer – Gold
  • Middle layer – Nickel
  • Botton layer – Copper

Insulation/Isolation Tests

Five Resistance Values against either of the two common points
All tested to 1,500 Volts.

  • 0,5MΩ
  • 1MΩ
  • 2MΩ
  • 10MΩ
  • 20MΩ

These are all the realistic values which may be encountered during actual insulation resistance testing.
0.5M , 1M & 2M are particularly relevant to BS7671 IEE Wiring Regulations:

Continuity Tests

Five Resistance Values all measured against either common point.

  • 0,25Ω
  • 0.5Ω
  • 5 Ω

The most critical areas of testing for R1+R2 or simply R2 are usually within the parameters of the CalCard

Contact Plates

The use of recessed sunken pads instead of panel mounted sockets, simplifies probe location and speeds up the check time – there is no need to remove instrument probes.


Yes it is Credit Card sized. Not to be hidden or buried in a van’s or tool box, it can be stored with the instrument, where you would need it.

Strong and Waterproof

Comprised of laminated layers on a multi-layered glass fibre base, it provides a very tough resilient product that is both moisture resilient and strong enough to survive the working environment.

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