Contact Resistance & Impedance Testing

MATCO  Services has the capability to perform high precision direct current contact resistance and alternating current contact impedance measurements on a variety of materials, including bare and coated metallic materials. These resistance and impedance measurements may be made under applied under mechanical loads using a multi-speed load frame and calibrated 1,100 lbf digital load cell. The photograph below illustrates a mechanically loaded test arrangement where an electroplated steel sample is placed between copper electrodes.

For direct current contact resistance measurements, a nano-volt/micro-ohm meter is employed. Using low-noise input amplifiers and a highly tuned input protection scheme to reduce reading noise down to 8 nVpp, the meter provides 7.5 digit resolution and 100 pv / 100 nΩ sensitivity. The meter is calibrated and NIST traceable. It is shown in the photograph below.

For alternating current impedance measurement, a variable frequency LCR meter with four terminal probes provides a measurement frequency range of from 42 Hz to 5 MHz. The measurement resolution provides a five full digits, and the basic measurement accuracy is + 0.08%. The meter is calibrated and NIST traceable. It is shown in the photograph below.

Data acquisition and analysis capabilities are provided by a RS-232 connection between the meter and a notebook computer running software, which allows the export of collected data to Excel spreadsheets.

In addition to Dr. Zee, other Matco staff members working this project include:

Dr. George T. Bayer, Technical Manager

Dan Gibson, Senior Technician

Sam Scheinman, Physicist