15

Ayrton-Mather Galvanometer. (Fig. 7.)

“ Galvanometers,” by Ayrton and Mather, Phil. Mag., Vol. XXX., page 58, July 1890.

FIG. 7.

This is an instrument of the “ moving coil ” type, the coil and magnet being of the form found by Messrs. Ayrton and Mather to give the greatest sensitivity for a given period.

The coil is wound with non-magnetic wire, and after winding, it is treated by a chemical process to eliminate all traces of magnetic material in the silk covering of the wire,or in the former. The whole of the moving system is enclosed in a dust tight tube, so that suspended systems of different resistance and period, &c., may be quickly interchanged. The suspension is provided with a torsion head and clamping device. One terminal is connected to frame to eliminate electrostatic forces, and the levelling screws are fitted with ebonite insulating toes.

The period of the instrument is usually arranged to be eight seconds, though longer periods may be obtained for ballistic work.

A damping coil, which can be placed in circuit by depressing a key, is fitted to each suspension tube. This coil is so arranged that, when in circuit, the movement is nearly aperiodic.

---

Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour cette page est de 99,24 %.

La langue de reconnaissance de l'OCR est l'Anglais.

---