Humboldt State University

Robert A. Paselk Scientific Instrument Museum

Instrument Parts/Repair Help

The information provided via this page is intended to aid those repairing/restoring old instruments. It consists of responses I have made over the years to requests for help with restoration.

If you are interested in replacing missing parts, I have linked a set of emails describing a successful restoration of a missing chain by a user of this site as an example of what can be done - Rich

Chemical Balances

A brief set of instructions for cleaning a balance, originally provided by Fisher Scientific, is provided on-line: Directions for Cleaning a Balance From: Fisher Scientific Company. Modern Laboratory Appliances (Catalog 90). Fisher Scientific Company and Eimer and Amend (1942, reprinted 1946) p 48.

The operation and general care of chemical balances may be found in any vintage (<1975) analytical chemistry text. A fairly thorough early treatment is available here on-line: Weighing from Smith, George McPhail. ...QUANTITATIVE CHEMICAL ANALYSIS ... (1921).

A more advanced treatment on the set-up and repair of balances is also available on-line: The Use and Care of a Balance by Peter J. Krayer (1913). This treatment does not seem to have been superceded in English, and is highly recommended.

A general description of the care and operation of analytical balances focusing on Christian Becker Chain balances is also provided on line: Care and Use of Analytical Balances. This is the complete text of a brochure provided by Christian Becker division of Torsion Balance Company (1952)

Instructions for Assembly and Adjustment of Christian Becker Chainomatic Balances. These typed instructions were found under an instrument in HSU's physical chemistry lab. They probably came with our AB-2 balance in the 1950's. pg 1, pg 2, pg 3, pg 4, pg 5.

Some of the important variations of the Christian Becker line of chain-weight balances are illustrated and briefly described on-line in: Christian Becker Analytical Balances from Braun-Knecht-Heiman Co., Catalog No. 40, Laboratory Instruments Apparatus Supplies, (1940)

The directions provided in the lid of the box originally carrying the beam, pans etc. for a SeKo two pan balance is provided in two resolutions: SeKo Directions for Setting up a Balance from Seederer-Kolbush (c. 1960) (Higher Res)

Balance parts: Illustrations and specifications for some parts commonly needing replacement are given below. Linked photos generally include a rule for comparison and/or dimensions. All dimensions were determined with 6" dial or digital calipers unless otherwise noted.


Christian Becker


Optical Equipment

AO-Spencer Spectroscope

Prism table:

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HSC (1954-1973)

© R. Paselk

Last modified 9 February 2016