Load sensor

Abstract

Abstract PURPOSE:To widen a load measurement range and to improve precision and temperature characteristics by forming a compressible hermetically-sealed container which varies in internal capacity with an external load and installing a crystal oscillator in the hermetically-sealed container in contact with fluid filling the enclosed container. CONSTITUTION:The internal space of the hermetically-sealed container 3 is filled with an inert dry gas, e.g. gaseous nitrogen and the crystal oscillator 7 is provided on the reverse side of an upper plate 4. A load transmission shaft 9 extends from the upper plate 4 and pierces a housing 8 in a free reciprocating state. A platen 10 which is loaded is fitted to the upper part of the shaft 9 and a spring 11 is fitted between this platen 10 and housing 8. A couple of lead wires from the crystal oscillator 7 are connected to the oscillation circuit of an electric circuit 12 fitted to the housing 8. When the platen 10 is loaded as shown by an arrow A to press down the upper plate 4, the pressure of the gas rises as the capacity of the hermetically-sealed container 3 decreases, and the oscillation frequency of the crystal oscillator 7 decreases.

Inventors

• 👤 Koichi Ichihara
• 👤 孝一 市原

Bibliographic Details