| 摘要 |
PURPOSE:To perform accurate measurement all the time, to omit manual read- justment, and to reduce reduction in manhours for maintenance and inspection, by automatically performing the adjusting operation of the zero point of an electric signal periodically. CONSTITUTION:During the measurement, solenoid valves MV1 and MV2 are opened and a solenoid valve MV3 is closed, and pressures P1 and P2 are applied to diaphragms. When a zero point is automatically adjusted, the solenoide valves MV1 and MV2 are closed and the solenoid valve MV3 is opened, airtight chambers 1a and 1b are communicated by a bypass pipe 6c and the difference in pressures, which are applied to the diaphragms becomes a zero state. Lines L1 and L2 from a control device are connected to a converter part 7. The detected outputs of a sensor are converted into current values that are connected to the lines L1 and L2. The measured pressure difference is transmitted in this way. The converter part 7 periodically performs the automatic adjusting operation and sends a control signal to a driving part 8. The solenoid valves MV1-MV3 are controlled through lines L3 and L4. The zero adjustment of the value of the transmitting current is automatically performed. |
