Patent ID: 6886413

Claim:
A flow rate sensor comprising: a first body including a first side and a second side opposite to each other, a first passage defined in the first body and communicating with the first side and the second side, the first passage having a diameter gradually reduced relative to the second side of the first body, a first path defined in the first body, the first path extending to the second side of the first body and communicating with the first passage for transmitting a different of a pressure value in the first passage; a second body airtightly and detachably abutting to the second side of the first body, the second body having a first side and a second side opposite to each other, the second side of the second body abutting the second side of the first body, a second passage defined in the second body and communicating with the first side and the second side of the second body, the second passage having a diameter gradually reduced relative to the second side of the second body and co-axially communicating with the first passage in the first body, a second path defined in the second body, the second path extending to the second side of the second body and communicating with the second passage for transmitting a different of a pressure value in the second passage, the second path in the second body corresponding to the first path in the first body; and a sensing device sandwiched between the first body and the second body and having a top portion extending out of the first body and the second body, a chip securely attached to one side of the sensing device facing the second path in the second body and corresponding to the first path in the first body for calculating the different of a pressure value from the first passage and the second passage, a first O-ring airtightly mounted between the first body and the sensing device and a second O-ring airtightly mounted between the sensing device and the second body, the first O-ring and the second O-ring fully containing waterproof glue to prevent the sensing from being wetted due to the fluid in the flow rate sensor.