Ishida Scales Mfg. Co., Ltd.

Seiji Nishide

Kazufumi Naito

Hiroyuki Konishi

Noboru Kosugi

A load cell has a cantilever-type load-sensitive element with an upper beam and a lower beam, each having formed thereon a pair of strain-generating parts which generates a strain corresponding to an applied load. Only one of these two beams has an indented part formed on its surface and strain-detecting elements are attached to its bottom surface at positions corresponding to the strain-generating parts. A moisture-proof sheet is attached to the beam to completely seal the interior of this indented part to protect the strain-detecting elements from humidity and moisture.

Load cell

Strain gages are attached to respective strain sensing areas of the strain generator of a load cell. Those strain gages which are mounted on expansive sides of the strain generator are connected in series with each other, and those strain gages which are mounted contactive sides of the strain generator are connected in series with each other, forming first and second series-connected circuits. The first and second series-connected circuits are connected in series with each other as a half bridge. A load applied to the strain generator is detected by an output signal produced from the junction between the first and second series-connected circuits. A temperature compensating resistor for compensating for a temperature-dependent change in the output signal due to a change in the temperature of the strain generator is connected in a circuit separate from the half bridge. Gain control is effected to eliminate a change in the output signal from the load detecting circuit based on a change in the resistance of the temperature compensating resistor.

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Shiga, Japan

Seiji Nishide