| 摘要 |
A relative movement sensor that may be used to measure the force applied to a beam, for example to provide an onboard weighing system for a truck. The sensor measures relative movement between first and second portions of the beam, and includes a housing connected to the first portion and a mounting block connected to the second portion. An optical source and a pair of optical detectors are secured to the housing. A line between the first and second portions define a first axis, and a line between the source and a point midway between the detectors defines a second axis. The mounting means mounts a beam modulator between the source and detectors, such that relative movement as between the first and second portions results in movement of the beam modulator with respect to the housing. A measurement circuit provides an output signal corresponding to the relative illumination falling on the detectors. The beam modulator is shaped such that the output signal varies as the beam modulator moves along a third axis perpendicular to the first and second axes. The beam modulator may comprise a plate having a slit, the width of the slit along the third axis being substantially constant.
|
