31. Model C pH Electrometer

Antique lab item. Duplicate of another item in museum collection. Cube shaped box, light wood, top lid hinged at back with central metal handle. Inside is black plastic control panel for device, featuring a number of dials, switches and meters. Affixed to the inside of the lid is a page featuring printed information and instructions. A small door at front opens out, to reveal black/clear glass apparatus and an electrode. Jones pH Electrometer: This design originated in the 1930s but was still made in 1960. The voltage corresponding to pH was measured indirectly. Jones's meters cornered the market during WWII and were reliable workhorses. Maker: N.L. Jones, Melbourne.

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