| 摘要 |
PURPOSE:To provide an automatic flowmeter for measuring flow rates of liquid accurately and efficiently by fitting a buret with multiple pairs of photoelectric switches. CONSTITUTION:In a normal condition, the first open/close value OV-1 is open and the second open/close value OV-2 is closed, and further, the liquid level in a buret is at the position of the first photoelectric switch SE-1. When flow- rate-start instruction is issued, the open/close value OV-1 closes and the open/ close value OV-2 opens, so that the liquid level drops. When the second photoelectric switch SE-2 detects passage of the liquid level, a time stars counting. When the third photoelectric switch SE-3 detects passsage of the liquid level, the drop time of the liquid level is measured for calculating flow rate of the liquid, then, the open/close value OV-1 opens before the liquid in the buret disappears, so that the liquid level in the buret rises. When the liquid level reaches the position of the switch SE-1, the open/close value OV-1 opens and the open/close value OV-2 closes, thus returning into normal condition. |
