| 摘要 |
PURPOSE:To set an adequate differential pressure corresponding to the installation situation of a ventilator and properly indicate the clogging degree by a method wherein a differential pressure indicator is equipped with a differential pressure setting device to optionally set a differential pressure value. CONSTITUTION:A differential pressure sensor main body 7 has two pressure detecting ports 9a and 9b. The pressure detecting port 9a detects the pressure of the inside 10 of a ventilator, and the pressure detecting port 9b is connected to a pipe 11, that is extended from the inside of the ventilator into a room, to detect the pressure of the inside 12 of the room. The differential pressure between the pressure detecting ports 9a and 9b is converted into an electric signal. When the ventilator is operated for a long time, dust attaches on a filter 8 and the differential pressure across the filter 8 increases, resulting in an increase in the differential pressure between the inside of the ventilator and the inside of the room. A differential pressure indicator 15 is equipped with differential pressure setting members such as a volume control knob, a changeover switch, or others, and the differential pressure value is set during or after the installation work of the ventilator. |
