| 摘要 |
<p>PURPOSE:To detect contamination of bathtub water automatically by providing a translucent part at a part of an additional heating line, projecting light from a light emitting element toward the translucent part and then receiving the scattering light by a light receiving element. CONSTITUTION:When a bath heater 2 is operated to start circulation of bathtub water through an additional heating line 3, a water flow switch 10 is turned ON to drive a control circuit 15 and power is fed to the light emitting element in a contamination sensor 9 thus emitting the light therefrom. The light is scattered on the bathtub water passing through the translucent part of the sensor 9 and received by a light receiving element disposed oppositely thereto. The control circuit 15 converts the output from the light receiving element into a signal corresponding to the extent of contamination of bathtub water. When the extent of contamination exceeds a threshold level, it is notified on a display 14 and an alarm is delivered thus preventing additional heating of significantly contaminated bathtub water.</p> |
