Accession No
4023
Brief Description
moisture indicator, by Cambridge Instrument Company Inc., U.S.A., c.1930
Origin
U.S.A; New York; Ossining
Maker
Cambridge Instrument Company Inc.
Class
metrology
Earliest Date
1930
Latest Date
1930
Inscription Date
Material
metal; glass
Dimensions
length 203mm; breadth 112mm; height 121mm
Special Collection
Cambridge Instrument Company Collection
Provenance
Donated by the Cambridge Instrument Company.
Inscription
‘CAMBRIDGE
INSTRUMENT CO. INC.
OSSINING N.Y.
No O-5356’ (plate below scale)
‘LACKS
GOLD BEATER
SKIN’ (paper label attached to instrument)
Description Notes
Handheld moisture indicator in black-painted metal case. The horizontal glazed scale above the handle is marked ‘PER CENT RELATIVE HUMIDITY’ and divided 10 - 90%. On the base is the detector which is a long metal plate with nine circular apertures with a fine wire mesh for protection. There is a label attached to the handle.
Condition: good, complete
References
Events
Description
A moisture indicator is designed so that it may be placed in contact with material during manufacture (e.g. coffee, yeast), in order to determine the degree of moisture in the product.
The moisture indicator contains a sensitive hygroscopic element the length of which changes in accordance with variations in the moisture content of the surrounding atmosphere. Traditionally this element was a human or animal hair under tension, however in this more modern instrument the element comprises of a strip of Goldbeater’s skin (the outer membrane of calf’s intestine) under tension.
As the Goldbeater’s skin’s length changes with humidity, this moves a link mechanism attached to the instruments display needle. Any small variations in the length of the Goldbeater’s skin are, therefore, translated into a change in the indicated moisture % on the display.
30/11/2007
Created by: Joshua Nall on 30/11/2007
FM:44311
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