Compact pressure and flow sensors for very high temperature and corrosive fluids

A capacitive pressure transducer, comprising:

• a housing that encloses a space, a side of the housing comprising a resiliently deformable or flexible membrane that deforms or flexes in response to pressure changes outside of the housing in a pressure range to be measured or monitored, wherein the housing and the membrane comprise a material that is corrosion resistant;
• a capacitor formed by a first electrode and a second electrode positioned inside the enclosed space and held apart from each other by one or more non-electrically conductive stand- off supports, the first electrode being resiliently deformable or flexible toward or away from the second electrode;
• and
• a pusher in the enclosed space that extends from the membrane toward the first electrode.

A method of measuring pressure of a very high temperature fluid, comprising:

• placing a transducer in the fluid, wherein the transducer comprises:
• (i) a first pressure sensitive element, wherein the first pressure sensitive element comprises a first housing that encloses a first space, and wherein one side of the first housing includes a resiliently deformable and electrically conductive first membrane;
• and (ii) a second pressure sensitive element disposed adjacent to the first pressure sensitive element, wherein the second pressure sensitive element comprises a second housing that encloses a second space, and wherein one side of the second housing includes a resiliently deformable and electrically conductive second membrane, and further, wherein the second pressure sensitive element is positioned and oriented such that the second membrane is juxtaposed to the first membrane with a distance between the first membrane and the second membrane;
• applying a voltage across the first membrane and the second membrane;
• measuring capacitance between the first membrane and the second membrane;
• and
• determining the pressure of the fluid by comparing the capacitance to a predetermined correlation of capacitance measurements to pressures,

A flow meter sensor for sensing flow of a high temperature fluid, comprising:

• a transducer comprising a housing that encloses a space, said housing comprising a corrosion resistant material that can withstand high temperatures of the fluid for which flow is sensed, including one side of the housing comprising a ceramic substrate with a surface outside of the housing and another surface that is inside the housing, and a plate or cladding comprising a corrosion resistant material that can withstand the high temperatures of the fluid for which flow is to be sensed with the flow meter sensor;
• and
• a sensor element mounted on the surface of the ceramic substrate that is inside the housing, said sensor element comprising an electrically resistive material, the resistivity of which varies as a function of temperature, and which can withstand the high temperatures of the fluid for Which flow is sensed;
• a sensor element mounted to the housing, said sensor element comprising a temperature-sensitive set of materials which can withstand the high temperatures of the fluid for which flow is sensed.

A method of detecting mass flow rate and flow direction of a fluid, comprising:

• positioning a core material in the flowing fluid, the core material having a peripheral surface and a center;
• producing heat in the core material with a heater positioned at the center of the core material;
• measuring temperatures at each of at least three locations at or near the peripheral surface of the core material with at least three temperature sensors positioned respectively at the three locations, wherein the three temperature sensors are spaced apart angularly in relation to each other and radially outward from the heater;
• and
• indicating windward direction of the flowing fluid in relation to the core material as a side of the core material on which the temperature measurements are lower than the temperature measurements on other sides of the core material.