This is an improved form comprising a coil of different number
of turns ( 500, 1000, 2000 or 5000 turns) of 36 SWG copper wire wound on an
aluminum metal ring (150 mm dia.) A stop limiting rotation to 180º of the ring
is provided with the help of the spring. The cradle supporting the coil of cast
non-magnetic alloy 200 x 210 x 115 mm high may be placed either on its base or
side so that the axis of rotation of the coil is either horizontal or vertical
. Terminals for connections are mounted on the cradle supporting blocks.
