Apparatus for testing electrical resistivity of liquids

Claim 1

IN A PORTABLE DEVICE FOR USE IN MEASURING THE RESISTIVITY OF A LIQUID COATING MATERIAL, A GENERALLY CYLINDRICAL, VERTICALLY EXTENDING BODY OF INSULATING MATERIAL, AN ELECTRODE CONNECTED TO THE UPPER PORTION OF SAID BODY HAVING AN OUTER TUBULAR PORTION SPACED RADIALLY OUTWARDLY FROM AT LEAST A PORTION OF SAID BODY AND EXTENDING AXIALLY DOWNWARD TO A POINT BELOW THE LOWER END OF SAID BODY, AN INNER ELECTRODE MOUNTED CONCENTRICALLY ON SAID BODY ADJACENT THE LOWER END THEREOF, SAID INNER ELECTRODE BEING ABOVE THE LOWER END OF SAID OUTER ELECTRODE PORTION AND HAVING ITS UPPER END SPACED DOWNWARDLY FROM THE UPPER END OF SAID BODY, BOTH DIMENSIONS OF THE SURFACE OF SAID INNER ELECTRODE EXPOSED TO SAID OUTER ELECTRODE BEING MANY TIMES THE RADIAL GAP BETWEEN SAID INNER AND OUTER ELECTRODES, SAID INNER ELECTRODE AND SAID OUTER ELECTRODE PORTION DEFINING AN ANNULAR LIQUID RECEIVING SPACE OPEN AT ITS LOWER END, AND TERMINALS ELECTRICALLY CONNECTED TO SAID OUTER AND INNER ELECTRODES, SAID DEVICE BEING PROVIDED WITH A VENT OPENING FOR VENTING AIR FROM SAID ANNULAR LIQUID RECEIVING SPACE AS THE DEVICE IN AN UPRIGHT POSITION IS LOWERED INTO THE LIQUID COATING MATERIAL.