| 摘要 |
PURPOSE:To prevent the sudden lowering in the vacuum degree or contamination within a chamber due to the sudden discharge of gas, by allowing a vacuum gauge to automatically pass a reset state in a process altering a measuring state and a degassing state. CONSTITUTION:When the signal S102 of an input terminal 102 for setting a vacuum gauge to a degassing state is H in such a state that the signal S111 of an input terminal 101 for setting the vacuum gauge to a measuring state is H, a state such that not only the signal 111 but also the signal 102 of an output terminal 112 for realizing the degassed state become L is generated only for a time t1. After the elapse of the delay time t1, H of the Q'-output of FF 131 is transmitted to one of the input terminals of an AND gate 142 and, since the other input terminal of the gate 142 is connected to the Q-output terminal of FF 122 and has become H, the output terminal of the gate 142 becomes H. Since the output terminal of the gate 142 is connected to the set input terminal of FF 132, FF 132 becomes a set state and the output terminal 112 becomes H. By this method, the vacuum gauge makes a soft start to become the degassing state.
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