| 摘要 |
PURPOSE:To detect the presence or absence of the clogging of a nozzle by operating and obtaining the flow-path resistance value of a draining system when water is drained, and comparing the result with a predetermined numerical value. CONSTITUTION:When a pressure reducing pump 3 starts sucking, an initial-pressure- measuring-timing signal is sent from a timing circuit 11 into a sampling circuit 8. The circuit 8 samples the output (initial pressure) of a pressure gage 7 and sends the result into an operating circuit 13. The signal of the pressure change is sent into a differentiating circuit 9 from the pressure gage 7, and the differentiated signal is obtained. A time measuring circuit 10 measures the time between the differentiation peaks, obtains the draining time and sends the result into the operating circuit 13. The operating circuit 13 obtains the flow-path resistance based on the amount of liquid in the reaction container 1, a constant, the initial pressure and the draining time. In a comparing circuit 15, the obtained flow-path resistance is compared with the flow-path resistance value, which is preset in a reference signal source 14. When the difference between the obtained value and the reference value of the flow-path resistance exceeds the allowable range, the comparing circuit 15 judges the abnormality. A control circuit 16 issues the alarm so as to stop a washing mechanism. |
