| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly, quickly and automatically judge the safety of waste water of a construction work at low cost. SOLUTION: The apparatus is provided with a water tank 1 where construction waste water is supplied and a fish 4 is bred, a light-emitting part 2 and a light-detecting part 3 of an optical sensor arranged in the water tank. Moreover, the apparatus has an alarming device 8 which alarms when a signal indicating passing of the fish is not detected by the light-detecting part for a predetermined time.</p> |
