Electrical apparatus for measuring pressure

Claim 1

MEASURING APPARATUS COMPRISING IN COMBINATION A CHAMBERED STRUCTURE INCLUDING AN UPPER VAPOR SPACE, A SUBJACENT CHAMBER OPEN AT ITS UPPER END TO SAID VAPOR SPACE, A CONDUIT HAVING ONE END CONNECTED TO THE LOWER PORTION OF SAID CHAMBER AND EXTENDING UPWARD THEREFROM, A BODY OF ELECTRICALLY SHORT CIRCULATING LIQUID FILLING LOWER PORTIONS OF SAID CHAMBER AND SAID CONDUIT, A BODY OF VOLATILE NON-CONDUCTIVE LIQUID IN SAID CHAMBER ABOVE AND SUPPORTED BY SAID SHORT CIRCUITING LIQUID, AN ELONGATED RESISTOR IN SAID CHAMBER HAVING ITS UPPER END ABOVE SAID VOLATILE LIQUID BODY AND HAVING ITS LOWER END IMMERSED IN SAID SHORT CIRCUITING LIQUID AND DIRECTLY CONTACTING SAID VOLATILE LIQUID IN AN INTERMEDIATE REGION, A HEATING CIRCUIT INCLUDING SAID RESISTOR AND INCLUDING AN ELECTRIC CURRENT SOURCE, WHEREBY A VARIABLE FLUID PRESSURE TRANSMITTED TO THE UPPER END OF SAID CONDUIT RAISES AND LOWERS THE UPPER SURFACE LEVELS OF THE SHORT CIRCUITING LIQUID AND VOLATILE LIQUID IN SAID CHAMBER AS SAID PRESSURE RESPECTIVELY INCREASES AND DECREASES AND THEREBY RESPECTIVELY DECREASES AND INCREASES THE RESISTANCE OF SAID CIRCUIT AND RESPECTIVELY INCREASES AND DECREASES THE TEMPERATURE OF THE VOLATILE LIQUID, AND TEMPERATURE RESPONSIVE MEANS ASSOCIATED WITH SAID CHAMBER AND PROVIDING A MEASURE OF THE PRESSURE IN SAID CONDUIT.