| 摘要 |
PURPOSE:To prevent the lowering in the residual amount detecting function when the quantity of light is insufficient, by mounting a correcting optical sensor for detecting the quantity of light outside a chemical agent tank and comparing the quantity of the receiving light of said sensor with that of the residual amount detecting optical sensor in the chemical agent tank. CONSTITUTION:When a chemical agent 6 is received in a chemical agent tank 1, since a sensor rod 2 is immersed in the chemical agent 6 up to the midway thereof, the quantities of the receiving light of residual amount detecting optical sensors 3-3, 3-4, 3-5 are reduced and the quantities of the receiving light of optical sensors 3-1, 3-2 do not change. In this case, since the quantity of the light received by the residual amount detecting optical sensor 3 is not always constant, a correcting optical sensor 4 detects the quantity of light outside the chemical agent tank 1 to send the signal corresponding to the quantity of light to a display part 5. Since the quantity of light of the residual amount detecting optical sensor 3 and that of the correcting optical sensor 4 are corrected by a compensation circuit 8, the display part 5 receiving said signal displays the signal as a proper residual amount value by an LED 9. |
