| 摘要 |
<p>A method of judging acceptance/rejection of strain gauge type pressure sensors (1) depending on leakage, wherein the pressure sensor (1) measures the pressure by a strain voltage occurring from the difference between the vacuum inside the sensor container and a pressure applied to a pressure introduction portion. When inspection is carried out for judgement, a high D.C. voltage is applied between a terminal (2a) for short-circuiting all the electrodes (2) and a metallic container (6) by a power supply (8) for generating a high D.C. voltage. A resistor (7) having a high resistance value selected to keep discharge current from destroying an IC circuit inside the metallic container (6) is inserted between the positive terminal of the power supply (8) and the terminal (2a). The high D.C. voltage from the power supply (8) is controlled by a computer (13). The voltage is slowly changed in the beginning, and is turned OFF after a discharge of one pulse. The vacuum pressure inside the metallic container (6) is measured from the discharge current Id of one pulse in accordance with the Paschen's law. This measurement is repeated at two-week intervals, for example, and a mean pressure change ratio during this period is determined. If this pressure change ratio exceeds a predetermined value, the product is rejected because of leakage.</p> |
