Humboldt State University ® Department of Chemistry

Robert A. Paselk Scientific Instrument Museum

Analytical Balance Weights

Central Scientific Co. (Cenco)

provenance: Humboldt College; c.1952

Usage

This is an analytical grade, Class S-1,weight set, used for high quality mass determinations in conjunction with an analytical balance. Class S-1 weights are intended for standard analytical use, since they are slightly less precise than the Class S weights (see Laboratory Weights, below). The quality of this set would indicate its intended use in analytical chemistry courses. Such sets might also find use commercially for high quality work. HSU records show that this is one of four identical weight sets purchased in about 1952.

Descriptions of Weights and their use are provided in the links below:

• Weights in Krayer, The Use and Care of a Balance (1913). An early description of Weights and their use.
• Laboratory Weights, Cenco (1950) Cat J- 150 General Catalog Laboratory Apparatus & Scientific Instruments. Central Scientific Co., Chicago, pp 31-32.

Description

Class S-1 lacquered brass 1–50 gm, tantalum 50–500 mg fractional weights, aluminum 1–10 mg fractional weights, and two aluminum wire 10 mg riders. The set is complete including forceps (replacement).

The 5" x 4" x 2" wood box is of lacquered mahogany (see linked photo). The box is of mitered corner construction lined with black velvet., and a black plastic tray for factional weights. The box hardware is brass. There is a black and nickel plated CENTRAL SCIENTIFIC COMPANY tag on the lower right corner of the front of the box with raised letters. There is a partial decal: STATE OF CALIFORNIA / HUMBOLDT COLLEGE / 11450 and a number 2 on embossed tape, both on the box lid.