| 摘要 |
PURPOSE:To prevent a radiator from the puncture accident due to freezing by a method wherein data detected the engine coolant as electric signals in accordance with the freezing temperature of said coolant are compared with data detected the outside temperature as electric signals in accordance with said temperature CONSTITUTION:An optical conductor 3 composed of a light receiving part 3a and an illuminating part 3b is submerged in the coolant 2 of the radiator 1 and the light from a light source part 4 is detected, through the optical conductor 3, by a light receiving part 5 to output electric signal Va in accordance with the freezing temperature of the coolant. On the other hand, electric signal Vb in accordance with the outside temperature is outputted by means of a detecting part composed of a heat sensing element 7, resistors R1, R2 and R3. The both voltages are compared at a voltage comparator 9 and, when Vb is larger than Va, an output voltage Vc is outputted to an alarm means 10. |
