Quadrant electrometer, after Thomson and Branly — Teylers Museum

Quadrant electrometer, after Thomson and Branly

pre 1882

In the first century after the discovery of static electricity it appeared to be very difficult to determine the magnitude of an electric charge or an electric potential. The usual electroscopes only gave a rough indication. The quadrant electrometer, developed by William Thomson (1824-1907; later Lord Kelvin) in 1867, changed this situation.

In a glass box (which protected the experiment against air flow) four conductors are arranged in a quadrant. The conductors are connected in opposite pairs. One set is earthed, the other set is charged. A vane is suspended on a torsion wire between the conductors. The charge turns the vane. The torsion is read by means of a light beam via a tiny mirror on the wire, and is a measure for the electric charge.

Administration name

Fysisch Kabinet

Title

Quadrant electrometer, after Thomson and Branly

Translated title

Quadrant electrometer, after Thomson and Branly

Creator

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

Dating

[{'start': '1882', 'end_precision': u'', 'end': u'', 'start_precision': 'pre'}]

Measurements

[{'notes': u'', 'part': 'geheel', 'type': u'', 'value': '665', 'unit': u''}, {'notes': u'', 'part': 'voet', 'type': u'', 'value': '230', 'unit': u''}, {'notes': u'', 'part': 'voet', 'type': u'', 'value': '230', 'unit': u''}]

Object number

FK 0557

Inscription

[{'content': 'Electrometre Branly Construit par Bourbouze', 'type': u''}]

Reproduction reference

[{'reference': '..\\images\\Fysisch\\Gekoppelde afbeeldingen\\FK 0557.jpg'}]

Order image