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Non-Intrusive Liquid Flow Rate Sensor

IP.com Disclosure Number: IPCOM000103088D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 44K

Publishing Venue

IBM

Related People

Sherry, RW: AUTHOR [+2]

Abstract

Flow rate of liquid is determined by using two piezoelectric pressure sensors imbedded in a deformable thermoplastic liquid carrier. One sensor measures pressure transmitted through the thermoplastic by liquid upstream and the other downstream of a constriction in the liquid path. Thus, liquid flow rate is measured by the differential in the two pressure measurements without adverse effects of liquids on the sensors nor of contamination of the liquid by the sensors.

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Non-Intrusive Liquid Flow Rate Sensor

      Flow rate of liquid is determined by using two piezoelectric
pressure sensors imbedded in a deformable thermoplastic liquid
carrier.  One sensor measures pressure transmitted through the
thermoplastic by liquid upstream and the other downstream of a
constriction in the liquid path.  Thus, liquid flow rate is measured
by the differential in the two pressure measurements without adverse
effects of liquids on the sensors nor of contamination of the liquid
by the sensors.

      Referring to the figure, metal housing 2 contains Teflon liquid
flow cell 4 having an internal opening to carry the liquid
constricted to provide a relatively high impedance to flow in region
6.  Piezoelectric pressure sensor 8 provides an electric potential
proportional to pressure transmitted by the thermoplastic 4 upstream
of constriction 6 and sensor 10 provides voltage proportional to
downstream pressure.  The difference in voltage generated by the two
sensors is proportional to liquid flow rate.

      Since the thermoplastic material in contact with the liquid may
be selected to be chemically inert and to contribute no particles,
this sensor is particularly useful for its applicability for flow
rate measurements of a wide variety of liquids and of liquids which
must have very low particle content.

      Disclosed anonymously.