Potentiometer balance measuring system including a single source for continuous adjustment of range and zero set

Claim 1

IN A MEASURING SYSTEM HAVING A VOLTAGE DETECTOR INCLUDING AN INPUT CIRCUIT FOR APPLICATION THERETO OF A VOLTAGE THE MAGNITUDE OF WHICH IS TO BE MEASURED, A POTENTIOMETER HAVING AN ADJUSTABLE MEASURING SLIDEWIRE CONNECTED IN SAID INPUT CIRCUIT FOR DEVELOPING THEREIN A BALANCING VOLTAGE IN OPPOSITION TO SAID VOLTAGE TO BE MEASURED AND OF MAGNITUDE VARIABLE BY ADJUSTMENT OF SAID SLIDEWIRE, VOLTAGE INDICATING MEANS INCLUDING A SCALE, MEANS RESPONSIVE TO SAID VOLTAGE DETECTOR OR ADJUSTING SAID SLIDEWIRE IN A DIRECTION TO CHANGE THE MAGNITUDE OF SAID BALANCING VOLTAGE IN A DIRECTION TO DECREASE THE DIFFERENCE BETWEEN SAID VOLTAGE TO BE MEASURED AND SAID BALANCING VOLTAGE, AND AN ADJUSTABLE CURRENT SHUNT CONNECTED ACROSS SAID SLIDEWIRE, SAID SHUNT COMPRISING A COARSE CURRENT-ADJUSTING SECTION ADJUSTABLE BY STEPS THROUGH A GIVEN RANGE AN A FINEADJUSTING SECTION FOR MODIFYING THE CURRENT-ADJUSTING RANGE ESTABLISHED BY EACH OF SAID STEPS, THE COMBINATION OF MEANS FOR CONCURRENTLY CALIBRATING SAID VOLTAGE-INDICATING MEANS AND INTRODUCING INTO SAID INPUT CIRCUIT IN PLACE OF SAID VOLTAGE TO BE MEASURED A VOLTAGE OF MAGNITUDE EQUAL TO THE ALGEBRAIC DIFFERENCE BETWEEN VALUES SELECTED FOR PRODUCTION RESPECTIVELY OF OPERATION OF SAID INDICATING MEANS TO ITS LOWEST AND HIGHEST VALUES ON SAID SCALE COMPRISING A REGULATED CONSTANT VOLTAGE SOURCE, HAVING A HIGH DEGREE OF REGULATION FOR ESTABLISHING HIGH DEGREE OF PRECISION OF THE MEASUREMENT BY SAID INDICATING MEANS, ADJUSTABLE VOLTAGE-DIVIDING MEANS HAVING A PLURALITY OF VOLTAGE-SUBDIVIDING POSITIONS, AND