Abstract: The disclosed apparatus weighs a grown crystal that is being pulled from melt thereof. The lower end of a rope of known weight is connected to the crystal, while the upper end of the rope is connected to the drum of a rope-winding unit. The rope-winding unit includes a driver coupled to the drum so as to rotate the drum and wind the rope thereon, and the weight of the rope-winding unit including the drum and driver is known. At least one weight sensor is coupled to the rope-winding unit so as to measure the magnitude of gravity acting on the rope-winding unit. Whereby, the weight of the grown crystal is determined by subtracting the sum of the known weights of the rope and the rope-winding unit from the measured magnitude of the gravity acting on the rope-winding unit.

Abstract: The disclosed displacement detector uses a printed circuit board extending through a comparatively uniformly magnetized gap of a core. The core is essentially a closed loop of magnetic material enclosing a hollow space, and a magnetic material leg extends from a portion of the loop to the hollow space so as to define the above-mentioned gap between the extended end of the leg and a side of the loop facing therewith. A first coil is wound on the leg of the core. The printed circuit board has a second coil with a plurality of mutually spaced turns with slant portions, so that linkage of the magnetic flux of the core gap with the second coil varies depending on the relative displacement between the core and the printed circuit board. The slant portion of the second coil can be made symmetrical with respect to a center line parallel to the relative movement between the core and the printed circuit board.