Flow-meter probe

摘要

The invention provides a probe for a flowmeter which can be employed in various flow measuring devices utilizing semiconductor or ceramic thermistors. The invention comprises an apparatus for determining the fluid flow rate of a liquid passing through a conduit made of a material having a low thermal conductivity, comprising a probe disposed at least partially inside the wall of the conduit, part of the probe being substantially aligned with an inner surface of the wall, the probe being operationally connected to a control and display unit. The probe comprising a printed circuit board (PCB) on which at least two thermistors are mounted; an upstream thermistor serving for baseline measurements and a spaced apart downstream self-heated thermistor. The control and display unit repeatedly measuring the electrical resistance of the thermistors to generate signals which are electronically processed by the control and display unit to indicate flow rates.

主权项

1. An apparatus for determining the fluid flow rate of a liquid passing through a conduit made of a material having a low thermal conductivity, said apparatus comprising
a probe disposed at least partially inside the wall of said conduit, protruding surfaces of encapsulated components which are a part of said probe being substantially aligned with an inner surface of said wall, said probe being operationally connected to a control and display unit, said probe comprising a printed circuit board (PCB) on which at least two thermistors are mounted; wherein said at least two thermistors comprise an upstream thermistor serving for baseline measurements; and a spaced apart downstream self-heated thermistor for measuring changes in temperature resulting from a surface of said downstream thermistor being cooled by said liquid flowing through said conduit, said control and display unit repeatedly measuring the electrical resistance of said thermistors to generate signals which are electronically processed by said control and display unit to indicate flow rates.