Accession No

4591

Brief Description

pH meter, by Marconi Instruments Ltd., English, 1/2 20th Century

Origin

England

Maker

Marconi Instruments Ltd.

Class

laboratory apparatus

Earliest Date

1900

Latest Date

1950

Inscription Date

21-5-54

Material

wood; metal (brass, white metal, copper); plastic (ebonite and at least three others); paper; glass; foam

Dimensions

height 240mm; breadth 325mm; length 415mm

Special Collection

Provenance

Transferred from the Department of Physiology, University of Cambridge, on 23/01/1997.

Inscription

‘MARCONI INSTRUMENTS LTD.
pH METER, Type TF 511D’ (paper label in lid)
‘MARCONI INSTRUMENTS LTD
No 72334’ (on top face)

Description Notes

Wooden case with white metal handles at either end and a lockable lid with key. Inside case is a black plastic control panel; it carries an on/off switch, a temperature compensation dial, stand-by knob and knob for setting buffer, std potentiometer and two further dials, also electrometer unit and centre-zero galvanometer with needle, two ebonite terminals labelled ‘L’ and ‘E’. Two compartments, one containing seven batteries, 3 cuboid, 3 large cylindrical ones by different makers and a small cylindrical one, all packed in corrugated card. The other compartment contains a bottle with two buffer solution tablets in it and a detached plug; paper wadding. Inside lid is glued a paper label with instructions for use and service dates.

Condition fair; complete (label on lid is missing).

References

Events