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Abstract and Manuscript Management System - Abstract Detail |
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| Speaker: | Dean Jarrett |
| Title: | Procedures for the Traceability of High Resistance Standards Using a Teraohmmeter |
| Topic Group: | Electrical I |
| E-mail: | dean.jarrett@nist.gov |
| Co-Authors: | Marlin E. Kraft, Isabel Costro, Brett Degler, and Mark Evans |
| Abstract: |
The Metrology of the Ohm Project in the Quantum Electrical Metrology Division (QEMD) at the National Institute of Standards and Technology (NIST) routinely disseminates the U. S. representation of the ohm through our calibration services and measurement assurance programs. The measurement systems and procedures used to calibrate standard resistors and current shunts of nominal decade values in the range 10^-5 ? to 10^12 ? provide NIST customers with traceability to U. S. and international standards based on the quantum Hall effect. In recent years, a number of request have been received regarding the best practices for dissemination of high resistance (10 M? to 1 T?) from primary standard resistors calibrated by NIST to secondary standard resistors calibrated by our customers. The availability of a new generation of high resistance bridges, meters, and instruments with improved specifications, microprocessor based automation, software packages, and programmable parameters has given the measurement community more options but has also raised many questions regarding how to best disseminate the ohm in the high resistance range. Over the past year, we have worked with several customers and manufacturers to develop a set of procedures to meet today’s needs for disseminating the ohm at high resistances. NIST has provided designs and guidance for the development of improved high resistance standards with low voltage coefficient, low temperature coefficient, low drift rate, rapid settling time, and guarded components. Customers, such as the U. S. Department of Defense primary standards laboratories and Costa Rica's National Metrology Institute (NMI) Laboratorio Costarricense de Metrologia (LACOMET) and the Instituto Costarricense de Electricidad (ICE) have asked for guidance in supporting their ability to maintain and disseminate the ohm from the NIST calibrations of their primary high resistance standards to secondary standards laboratories using a digital teraohmmeter as the transfer device. NIST, our customers, and the teraohmmeter manufacturer have worked together to develop procedures and make the necessary measurements to meet customers’ needs for traceability to NIST by using the teraohmmeter as a transfer device. |
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