| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure the water levels by assuming the detecting state according to a difference between output values of a pressure sensor before and after a circulation operation and a difference between output value previously detected at a proper detecting state where air is not introduced into a circulation path and output value after air is introduced into the circulation path. SOLUTION: An output value of a pressure sensor 23 is obtained before a circulation operation. Then, a pump is operated to circulate water in a bathtub 18 through a circulation path 12 and an output value of the pressure sensor 23 during the circulation operation is obtained. A difference between the output values of the sensor 23 before and during the circulation operation is calculated. The calculated output difference is compared with an output difference between an output value previously detected at a proper detecting state where air is not introduced in the circulation path 12 and an output value after air is introduced into the circulation path 12. If the output difference is within an error range in measurement, the output value during the circulation operation is assumed to be the output value at the proper detecting state and the water level is calculated from the output value. |
