Thermal type flow measuring device

Details Thermal type flow measuring device Thermal type flow measuring device

2005-08-30

2005-08-30

Lefkowitz, Edward (Department: 2855)

Measuring and testing

Volume or rate of flow

Thermal type

Reexamination Certificate

active

06935172

ABSTRACT:
A thermal type flow measuring device comprises a heating resistor(HF), a temperature measuring resistor(Ru) upstream of the heating resistor(HF) with respect to a fluid(Q), and a temperature measuring resistor(Rd) downstream of the heating resistor(HF). A heat sensitive resistance element(CF), the upstream temperature measuring resistor(Ru) and the downstream temperature measuring resistor(Rd) form a first bridge circuit, and this first bridge circuit and the heating resistor(HF) form a second bridge circuit. Feedback control means(OP1, Tr) heat the heating resistor(HF) in accordance with an output for keeping a balance of the second bridge circuit. The distance between the heat sensitive resistance element(CF) and the heating resistor(HF) is larger than the distance between the upstream temperature measuring resistor(Ru) or the downstream temperature sensitive resistor(Rd) and the heating resistor(HF) so that the heat sensitive resistance element(CF) is positioned to receive less thermal influences from the heating resistor(HF) than the upstream temperature measuring resistor(Ru) and the downstream temperature sensitive resistor(Rd). The upstream temperature measuring resistor or the downstream temperature measuring resistor is heated by the heating resistor, and the flow rate of the fluid is measured based on an output for keeping a balance of the first bridge circuit.

REFERENCES:
patent: 5369994 (1994-12-01), Hecht et al.
patent: 5703288 (1997-12-01), Horiguchi et al.
patent: 5717136 (1998-02-01), Aoi et al.
patent: 6494090 (2002-12-01), Losing et al.
patent: 60-142268 (1985-07-01), None
patent: 2-120621 (1990-05-01), None
patent: 6-160142 (1994-06-01), None
patent: 2000-193505 (2000-07-01), None

Affiliated with

Also associated with

Rating

Thermal type flow measuring device 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 measuring device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal type flow measuring device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3523277