| 摘要 |
A method for making a plurality of stress sensors includes creation of cavities and corresponding diaphragms in a thin metal front plate, preferably by an acid etching process. A thin back plate, preferably comprising metal, is secured to the front plate over the cavities, preferably by welding. A plurality of strain gages is bonded to the diaphragms in the front plate with a layer of bonding agent such as epoxy. The bond layer is of substantially uniform thickness on at least that portion of the front plate where the diaphragms are located. As the bond layer cures, a magnetic force is applied to the diaphragms to reduce their movement toward the back plate, and to thereby assist in creating a bond layer of substantially uniform thickness near the diaphragms. A suitable magnetic force may be applied by positioning a rare earth magnet near the diaphragms. The magnetic force may be supplemented by a mechanical force. The method may further comprise the step of calibrating a plurality of the stress sensors with an automated calibration system. The present method provides a stress sensor whose total thickness is approximately 0.015 inches, and preferably only about 0.010 inches.
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