Humboldt State University

Robert A. Paselk Scientific Instrument Museum

The Chemist's Balance at Humboldt

Main Exhibit in the Science-A 4^th floor East Stairwell Cabinet

Exhibit Catalog

Introductory Essay: The Chemical Balance at Humboldt State, 1926-1986 by Richard A. Paselk, curator.

Double-pan Analytical Balances

Voland Student Analytical Balance (c. 1926; exhibited in Main Library south display case)
Christian Becker Student Analytical Balance (1948; exhibited in Main Library north display case)
Christian Becker Chainomatic Analytical Balance (1952)
Voland 200 Student Analytical Balance (c. 1950)
Ainsworth Student Analytical Balance (1956)
Voland Speedigram Analytical Balance (c. 1957; exhibited in Main Library north display case)

Single Pan Substitution Balances

thumbnail photo of Mettler balance

Mettler H5 Multipurpose (Analytical) Balance (1961)
Mettler H10 Analytical Balance (1971)
Mettler H10Tw Analytical Balance (1971) (1971; in storage-may be viewed by appointment with the curator)
Mettler M5 Micro Analytical Balance (1962)
Christian Becker/Torbal EA-1 Analytical Balance (1982; in storage-may be viewed by appointment with the curator)

Special Purpose Balances

Christian Becker Specific Gravity Balance (1959)
Mettler Demonstration Device (c. 1961; web exhibit only)
Roller Smith Precision Double-Hook Torsion Balance (1960; exhibited in Main Library north display case)

Weights

thumbnail photo of balance weights

Braun-Kneckt-Heiman-Co. Weight Set, 100 g - 1 mg, Student Analytical (c. 1926; exhibited in Main Library south display case)
Christian Becker Weight Set, 50 g - 1 mg, with 10 mg riders, Class XX (c. 1950; exhibited in Main Library north display case)
Central Scientific Co. Weight Set, 50 g - 1 mg with 10 mg riders, Class S-1 (c. 1952)
Christian Becker Weight Set, 50 g - 1 mg, Class S-1 (c. 1956)
William Ainsworth Weight Set, 100 g - 1 mg, Class S (NBS certified, c. 1961)
William Ainsworth Weights, 5 g & 50 g, Class M (NBS certified, 1962)
Voland Analytical Balance Riders
- Plastic rider box, earlier label with weight hand written (web exhibit only)
- Plastic rider box, later label with weight typed
- Riders (5 & 10 mg) Aluminum wire. Note that the 10 mg riders are used on balances with a scale with 0 over the beam center, and 10 over the pan hanger; the 5 mg rider is used on balances with a scale going from 0 - 10 pan-hanger to pan-hanger, with 5 at the beam center-point.

Supporting Documentation

Literature-Maker's Brochures, Manuals, etc.

Christian Becker:
- Directions: Christian Becker Chainomatic Balances; No.1 (1946) and No. 1A (1942)
- Instructions for Assembly and Adjustment of Christian Becker Chainomatic Balances
- Care and Use of Analytical Balances - scanned (jpeg) pages; OCR text with scanned photos
- Balance and Weight Set Bulletins (1936–1938)
- Weights description letter and price list (1957)
Mettler:
- H5 associated documents:
  - Mettler Service (brochure)
  - Mettler, Multi-Purpose Balances Directions for Use (brochure)
  - Folder and miscellaneous items (unpacking/setting up sheet; tri-fold brochure- Mettler balances; tri-fold brochure- Test, Test, Test)
- H10 associated documents:
  - Modern Analytical Balance poster (reduced (9"x 12") scan of original 24"x 36" poster)
  - Mettler H10/H20 Instructions (brochure)
- M5 associated documents:
  - Micro balance Unpacking and setting up
  - Mettler Micro Balances - M5 Directions for use
Seederer-Kolbush (SeKo):
- Directions for Setting up a Balance (c. 1960) (Higher Res)
- Herman Kohlbusch, Sr. Diamond Chain Balances Bulletin (1938)
- SeKo Catalogs (c. 1930, c. 1950, c. 1960)
Voland & Sons: Instructions for VOLAND Analytical Balances
William Ainsworth & Sons:
Weight Classification and Tolerances
- Summary of NBS Circular 547 from Van Waters and Rogers, San Francisco (1963) Catalog 63 Laboratory Instruments...etc.
- Essay, Laboratory Weights, Cenco (1950) Cat J- 150 General Catalog Laboratory Apparatus & Scientific Instruments. Central Scientific Co., Chicago, pp 31-32.
- Reprint (1978) of NBS Circular 547 Precision Laboratory Standards of Mass and Laboratory Weights (1954). National Bureau of Standards (now National Institutes of Standards and Technology [NIST]).

Balance Manufacturer Histories with Selected Catalog Listings

Christian Becker, Inc
E. Mettler, Inc.
Henry Troemner
Seederer-Kohlbusch (SeKo)
Torbal (includes additional information on Christian Becker as well as parent companies Vertex and Fulcrum)
Voland & Sons
William Ainsworth & Sons

Henry Heil Chemical Company. Illustrated Catalog and Price-List of Chemical Apparatus…etc. St. Louis, Mo. (1903): The complete selection of balances, scales and weights offered.

Miscellaneous Balance Information

Smith, George McPhail. "Weighing" from A Course of Instruction in QUANTITATIVE CHEMICAL ANALYSIS for Beginning Students. The MacMillan Company, New York (1921). A standard textbook discussion of weights and weighing for beginning college chemistry students.
Krayer, Peter J. The Use and Care of a Balance. (1913) This is the book on setting up and using an analytical balance. It does not seem to have been superceded since its publication in 1913. It has just been reprinted (2009) and is now available from booksellers such as Amazon™. I was recently contacted by Peter Krayer's grandson,William J. Krayer, who spent some time as a youth following in his grandfather's footsteps servicing balances. Two descriptive documents from William Krayer can be found below:
- Background Letter (pdf) This letter gives a bit of family history, and gives some context to balance maintenance during the peak of laboratory use of the two-pan analytical balance.
- Narrative on Analytical Balance Maintenance in the 1940's & 1950's (pdf) This insightful narrative briefly describes the work of cleaning and maintaining two-pan analytical balances, including many details of this lost trade.
Balance parts and Repair: Illustrations and specifications for some parts commonly needing replacement are given on the Instrument Care and Repair pages of this museum website.