Measuring and testing – Volume or rate of flow – Thermal type
Patent
1994-11-25
1997-04-22
Chilcot, Richard
Measuring and testing
Volume or rate of flow
Thermal type
G01F 168
Patent
active
056230974
ABSTRACT:
A heater-heat sensor type thermal flow sensor including a substrate installed in a fluid path, a channel formed on a part of the substrate; a bridge suspended over the channel; a heater constructed with an electric resistor formed on the bridge; a temperature sensor for measuring the temperature of the heater which is constructed with another electric resistor situated on the bridge and measuring the temperature of the heater; and a fluid temperature sensor constructed with still another electric resistor formed on a position of the substrate not thermally affected by the heater. There is a bridge circuit including the temperature sensor for measuring the temperature of the heater, the fluid temperature sensor, and first and second resistors both installed outside of the fluid path. A control circuit is provided to control the voltage applied to the heater in accordance with the output of the bridge circuit. The heater and the heat sensor are superposedly formed on the bridge through an interlayer insulating film in order to substantially eliminate the difference between the temperatures of the heater and heat sensor. A temperature compensating circuit is connected to the output stage of the control circuit.
REFERENCES:
patent: Re33076 (1989-10-01), Sugiura
patent: 5024083 (1991-06-01), Inada et al.
patent: 5353638 (1994-10-01), Marek
patent: 5392646 (1995-02-01), Yajami
patent: 5423210 (1995-06-01), Uchiyama
patent: 5423212 (1995-06-01), Manaka
Horiguchi Hiroyuki
Miyachi Tatsuo
Murata Norihiko
Artis Jewel
Chilcot Richard
Ricoh & Company, Ltd.
LandOfFree
Thermal-type flow sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal-type flow sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal-type flow sensor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-342925