| 摘要 |
Disclosed is an improved device for testing the compression, tension, or spring rate of a spring or other resilient material. The device is adapted to automatically display the load reading of a spring at a preselected height by merely compressing the spring past the check point. Alternatively, additional displays may be provided so that load readings at different height settings can be displayed with a single compression of the spring through all of the check points. In addition, the rate of a spring can be readily determined by setting two check points a unit distance apart and utilizing the load reading from the first check point to establish the reference level of the meter. The spring tester includes an electronic control circuit comprising a plurality of sample and hold circuits and a corresponding plurality of thumbwheel comparators. The comparators are connected to a height indicator and each is adapted to provide an output signal when the height of the spring corresponds to the preset height of the comparator. Each sample and hold circuit is connected to the load cell and to one of the comparators and is adapted to provide an output signal that follows the force reading from the load cell until the output signal from its respective comparator is received. When this occurs, the sample and hold circuit "holds" the current force reading of the load cell despite further compression of the spring.
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