The CalCard Ext 1 is made up of three layers: -

1. Top Face Legend.

The legend is printed under a clear plastic laminate to ensure that it lasts the lifetime of the card. It will not rub off smudge or be effected by water or moisture ingress.

2. Probe Access Guide.

The printed circuit board and its associated connection pads are located by a plastic former that is positioned and sealed on top. This former enables the probe tips to be easily located and held onto the pads with ease.

To ensure probe conductivity 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 a consistent measurement and protection to corrosion and tarnishing.

• Gold (0.3-0.7microns)
• Nickel (3-5 microns)
• Copper (35 microns)

3. Base PCB -Printed Circuit Board.

The printed circuit board forms the heart of the design and this is manufactured in a very strong multi-layered glass fibre construction 1.6mm thick.

It will easily withstand the normal day to day working environment.

Sealed from moisture and dirt ingress by the plastic former the CalCard EXT1 will withstand all the environments you would expect of the associated measurement instrument.