Accession No

3327

Brief Description

thermionic voltmeter, Moullin patent, or electronic valve voltmeter, by Cambridge Instrument Company Ltd., English, 1929

Origin

England; London

Maker

Cambridge Instrument Company Ltd.

Class

electrical

Earliest Date

1929

Latest Date

1929

Inscription Date

Material

plastic (ebonite); wood; glass; metal (brass)

Dimensions

length 195mm; breadth 159mm; height 91mm

Special Collection

Provenance

Transferred from Department of Engineering, University of Cambridge, Cambridge, England, 1986.

Inscription

‘No L 31725 (with logo)
CAMBRIDGE
INSTRUMENT CO. LTD. ENGLAND
PATT. 1’ (on dial)
‘CAMBRIDGE THERMIONIC VOLTMETER
MOULLIN PATENT No. 199483’ (on top)
‘E.B.M.’ (on top (added))

Description Notes

Ebonite top on wooden box; four-sided, arched, glazed window showing white dial; non-linear scale, 0 to 1.5 divisions; two pairs of brass terminals above window, marked ‘APPLIED POTENTIAL’ and ‘6 VOLTS’; two extra terminals (not shown in catalogue) to right of window; zero adjustment and clamping controls below window; circular glazed window on front of box with printed ‘INSTRUCTIONS’ on brass plate. Blueprinted circuit diagram glued to back; graphical, hand-drawn calibration chart glued to left side.
Similar to Wh: 3339.

Condition: good; complete.

References

Events