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.

RS3 Technical Specifications

Model	Value W	Accuracy	Max I Air (Amps)	Max I Oil (Amps)
RS3/0001	0.0001	0.02%	100	200
RS3/001	0.001	0.02%	32	60
RS3/01	0.01	0.01%	10	20
RS3/02	0.02	0.02%	7	14
RS3/05	0.05	0.01%	4.5	9
RS3/0.1	0.1	0.005%	3	6
RS3/1	1	0.005%	1.4	3
RS3/10	10	0.005%	0.44	1
RS3/25	25	0.005%	0.2	1
RS3/50	50	0.005%	0.1	0.3
RS3/100	100	0.005%	0.1	0.3
RS3/250	250	0.005%	0.1	0.3
RS3/1k	1k	0.005%	0.03	0.1
RS3/10k	10k	0.005%	0.01	0.03
RS3/100k	100k	0.005%	0.003	0.003
RS3/1M	1M	0.01%	0.0002	0.0002

 

Case Light alloy with holes in the side and base to allow free entry and exit of the oil flow. Black anodised finish to give maximum heat radiation. Top Panel Bakelite marked with the value class designation and serial number. Terminals Potential: - Copper 4 mm. Current: - Brass

Resistance Element Manganin or Zeranin depending on value. 100 Ω, 1, 10 and 100 kΩ low inductance winding on brass formers with P.T.F.E. insulation. 0.1, 1 and 10 Ω bifilar winding on cylindrical brass formers with P.T.F.E. insulation. 0.01, 0.001 and 0.0001 Ω resistance material in the form of straight rods or loops supported on 12 mm. diameter brass conductors.

Thermometer Tube Slotted extending the length of the resistance element. Label Each standard is fitted with a label that describes its characteristics and operating parameters. Size 160 mm high x 90 mm diameter Weight 0.9 kg approx.