Automating Data Acquisition on a Mechanical Equal Arm Balance Used in Large Mass Calibrations

Published

July 27, 2009

Author(s)

Kevin L. Chesnutwood

Abstract

This paper focuses on efforts by the Mass and Force Group at the National Institute of Standards and Technology (NIST) to enhance the data taking operations of an approximately 40 year old mechanical two pan equal arm balance used for high-precision mass comparisons in the range from approximately 45 kg to 1134 kg (100 lb to 2500 lb). The repeatability and sensitivity of this manually operated balance (called the Russell balance) cannot be matched by current digital comparator technology and therefore is still a core piece of the NIST large mass laboratory. In order to improve the data taking procedure and avoid reliance on human measurements done by eye, an automated system was designed and installed to obtain the turning points of the balance taken during calibration that ultimately are used to convert scale units to SI mass units. The paper discusses the advantages of the improved system, the challenges that had to be overcome, and the design, operation and verification of the automated system.

Proceedings Title

Proceedings of the National Conference of Standards Laboratories International (NCSLI)

Conference Dates

July 26-30, 2009

Conference Location

San Antonio, TX

Conference Title

NCLSI Workshop and Symposium

Pub Type

Conferences

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Keywords

Mass, Russell Balance, Mechanical Balance

Citation

Chesnutwood, K. (2009), Automating Data Acquisition on a Mechanical Equal Arm Balance Used in Large Mass Calibrations, Proceedings of the National Conference of Standards Laboratories International (NCSLI), San Antonio, TX, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=902420 (Accessed April 25, 2024)