| 摘要 |
<p>PROBLEM TO BE SOLVED: To allow detection of free flow occurring in a drip tube even if the brightness around the drip tube changes.SOLUTION: A signal processing part 10 of a droplet detecting device 1 includes: a first filter 13 which performs a process of acquiring a central value from the signal in a specific period which is outputted from an upper side first light receiving element 3 and upper side second light receiving element 4; a second filter 14 which performs a process of acquiring a central value from the signal in a specific period which is outputted from the upper side first light receiving element 3 and a lower side light receiving element 5; and a determination part 15 which, when a voltage difference between the signal obtained through processing with the first filter 13 and the signal obtained through the second filter 14 comes to be a specified value or higher, determines that a free flow is occurring in a drip tube 101.</p> |
