Absolute electrometer, after Thomson

Parijs Breguet, 1883

The purpose of an electrometer is to establish the magnitude of a charge or a voltage. This specimen is an ‘absolute electrometer’, because the value of the measurement can be expressed in so-called ‘absolute’ measures, that is measures from the international system of measures and weight (such as the kilogram and metre). William Thomson (after 1892 Lord Kelvin) devised this electrometer (and also his quadrant-electrometer, see cat. no 727) in 1867.

Under the glass dome are two parallel brass plates: one at a fixed height and the other one mounted on a spring balance (a push spring calibrated by weights). When a like charge is applied to both plates, they repulse each other. The displacement can be read through a lens. The desired result can be calculated.

Administration name

Fysisch Kabinet

Title

Absolute electrometer, after Thomson

Translated title

Absolute electrometer, after Thomson

Creator

[{'date_of_birth': u'', 'role': u'', 'qualifier': '', 'date_of_death': u'', 'creator': 'Breguet, Parijs'}]

Dating

[{'start': '1883', 'end_precision': u'', 'end': u'', 'start_precision': u''}]

Material

[{'material': 'brass'}, {'material': 'Glass'}]

Measurements

[{'notes': u'', 'part': 'geheel', 'type': 'hoogte', 'value': '800', 'unit': 'mm'}, {'notes': u'', 'part': 'voet', 'type': 'diameter', 'value': '430', 'unit': 'mm'}]

Object number

FK 0559

Inscription

[{'content': 'MAISON BREGUET ELECTROMETRE ABSOLU de SIR Wm THOMSON', 'type': 'signatuur'}]

Origins

Luns, Pierson & Cie, Parijs

Reproduction reference

[{'reference': '..\\images\\Fysisch\\Gekoppelde afbeeldingen\\FK 0559.jpg'}]