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Resistance Standards, Modular Series

Resistance Standard Rack Modular 6634A better than 2 ppm

RESISTANCE Guildline Instruments


  • Normal Ohms Resistance Range: 0.1 Ω to 100 MΩ in Single Decade Increments
  • Low Ohms Resistance Range provides 1 mΩ to 0.1 Ω in Decade Steps
  • Temperature Coefficient < ± 0.005 ppm/°C
  • Stabilities Low as < 2 ppm/year
  • Eliminates Oil Bath Requirements


  • 6634A series is a modular series of Resistance Standards that can be rack mountable or simply set on a bench. The 6634A Series provides a set of up to 10 precision resistance standards enclosed in a temperature controlled and EMI protected chamber. For the Normal Ohms Configurations, there are 10 standard resistance values available covering the range of 0.1 Ω to 100 MΩ. Each resistance element is isolated and has 4-terminal connections on the rear panel. The resistance elements are maintained at approximately 30 °C in a temperature stabilized chamber. Each element is built with Guildline’s “true” multi-element design.


National Measurement Institutes, military, and calibration laboratories.


More info on the RESISTANCE

Perfect for Automated Measurement Systems or as a Primary Laboratory Resistance Standard

The Model 6634A is excellent as a working standard for automated resistance measurement systems or as reference standards at the primary level. Special resistance values are available in the range of 0.001 Ω to 100 MΩ. Standard model variations are available with 5, 6, 7, 8, 9 or 10 resistance elements installed. All models purchased with less than 10 resistance standards can be expanded at any time via a factory upgrade. Special resistance values can also be ordered.

A New Low Ohms Configuration is now available for values below 0.1 Ω. This Series has the same precision temperature stability as the Normal Ohms Configuration, but is limited to a maximum of 3 Resistance Elements. This is due to the large size of the low ohmic elements. The Resistance Range of the Low Ohms models is from 1 mΩ to 100 mΩ.

One key advantage of Guildline Resistance Standards is that each Resistance Value is made up from multiple resistance elements, not just a single element which is the technique used by most manufacturers. This approach lowers the drift that is seen with a single element and reduces the internal noise generated inside the reference resistor. Other real advantages are the use of a PRT vs a thermistor for internal temperature control, and the Guildline 6634A Standard does not require any fans like competitive models. The result is industry leading annual drift rates and very quiet measurements.

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We are measurement system architects

We aim to exceed your expectations and provide solutions which add value to your business and make you more profitable. Our approach is simple yet effective; working with you to ensure that our solutions meet your requirements, perfectly.

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Or speak to our expert UK-based team now

UK +44 (0)1264 316470   US: +1 512 210 2288