The most desirable feature in which any resistance standard should excel is permanence of calibration. This has been achieved by the experience gained over many decades in the manufacture of precision resistors; the careful selection of resistance material, a rugged strain-free construction and a carefully controlled heat treatment and ageing process. To obtain the optimum performance from these standards, we recommend regular annual certification. A resistance standard which has been carefully used within the limits of the manufacturer's specification increases in usefulness with time, as its complete history is recorded, enabling the user to determine its value at any time.
The RS3 range of resistance standards are constructed using carefully selected low temperature coefficient Manganin or Zeranin wire, depending on value, mounted on formers which have a high mechanical stability. The wires are wound in a strain-free manner and heat treated to remove any stresses. They also are artificially aged under the strictest control. The result is a standard of high-quality with long-term stability and permanence of calibration combined with a low temperature coefficient.
We offer the widest range of
standard values available today. In addition we are able to
manufacture for specialist applications (e.g Pt100 simulation)
special values to customer requirements. The RS3 range also
offers a high-current carrying capability which makes them ideal
for applications where precise current needs to be measured.