| 摘要 |
PURPOSE:To obtain an output proportional to pressure by forming two pressure detecting sections the same in the characteristic on a one common semiconductor so that the residual strain equal between the two detecting sections to make the outputs of a bridge circuit due to the residual strain equal. CONSTITUTION:As two pressure detecting sections A and B are the same in the characteristic are formed on a one common semiconductor 1, the residual strain of the semiconductor 1 and the variation in the residual strain due to changes of the service temperature equal between the pressure detecting sections A and B. So, the output values of bridge circuits 4 and 4' based on the residual strain also are equal. When a pressure P to be measured is applied to the pressure detecting section A alone, the output of the pressure detecting section A gives the sum of V proportional to the pressure P and epsilon due to the residual strain. On the other hand, the output of the pressure detecting section B gives the output epsilon based on the residual strain. Therefore, difference between the two outputs is determined with differential amplifiers 10-12 or the like to obtain the output V purely proportional to the pressure P. This removes errors based on the residual strain and also eliminates effect from temperature. |
