This high-quality product is of meter bridge design and is intended primarily for the comparison of two resistance. A resistance wire negligible temperature coefficient is stretched over a meter ruler with millimeter graduations. Terminals, mounted on five plated brass strips, provide means for connecting resistors and a voltage source. These strips are separated by gaps that can be eliminated (as required) by using two further brass strips. A robust “jockey” (moveable contact) with lead is supplied for taking readings on the wire. A sprung clip provides convenient storage for the jockey.

Kit includes Wheatstone bridge, jockey, and covered wire lead with two conductive ends. Additional required equipment (not included): a center-zero galvanometer, typically reading 1mA 0 1mA. (More sensitive instruments can be used but care must be taken not to create current overloads which, on analogue meters, can result in bent needles.) as well as a dry cell (or equivalent with similar internal resistance). The use of low-voltage packs or secondary cells is inadvisable as over-heating and distortion of the resistance wire can easily occur.

The Wheatstone bridge apparatus measures 1 meter long (39.4")