Resistance Metrology

Martin Instrument Labs resistance measurement assurance program utilizes multiple reference resistors including Fluke 742A nitrogen filled, and Thomas style reference resistors.  Above, two reference resistors are prepared for stabilization in a constant temperature bath for direct measurements, and ratio metric comparisons.  Ratio metric measurements are utilized to calculate the calibration values and regressions of other reference resistors with very low uncertainty.

Above the long scale digital multimeter directly measures the resistance from two reference resistors.  Corrections are applied for the bias and predicted regressions of the standards.

The above the graph depicts the calculated 2s limits for  measurements of our FL5500A made by our HP3458A long scale digital multimeter.  The data is the results of over 250 measurements made since 2001.  This is the estimated uncertainty associated with our measurement assurance program, and not the combined standard uncertainties associated with our best measurement capabilities.