Compensated bridge circuit

Claim 1

A RESISTANCE BRIDGE ADAPTED TO USE IN CHROMATOGRAPHIC GAS ANALYSIS COMPRISING, IN COMBINATION, A D.-C. POWER SOURCE, FIRST AND SECOND TEMPERATURE-SENSITIVE RESISTORS HAVING A RELATIVELY HIGH TEMPERATURE COEFFICIENT OF RESISTANCE EACH CONNECTED AT ONE END TO A COMMON TERMINAL OF SAID POWER SOURCE, FIRST AND SECOND LOAD RESISTORS OF RELATIVELY LOW TEMPERATURE COEFFICIENT OF RESISTANCE EACH CONNECTED AT ONE END TO THE OTHER TERMINAL OF SAID POWER SOURCE AND AT THE OTHER ENDS SINGLY TO THE RESPECTIVE ENDS OF SAID FIRST AND SECOND TEMPERATURE-SENSITIVE RESISTORS REMOTE FROM SAID POWER SOURCE, THEREBY FORMING A PAIR OF OPPOSITE JUNCTIONS FOR SAID BRIDGE, A FIRST VOLTAGE DIVIDER OF RELATIVELY LOW TEMPERATURE COEFFICIENT OF RESISTANCE CONNECTED IN SHUNT RELATIONSHIP WITH RESPECT TO SAID FIRST TEMPERATURE-SENSITIVE RESISTOR BETWEEN THE JUNCTION OF SAID PAIR ADJACENT TO SAID FIRST TEMPERATURE-SENSITIVE RESISTOR AND SAID COMMON TERMINAL OF SAID POWER SOURCE, A SECOND VOLTAGE DIVIDER OF RELATIVELY LOW TEMPERATURE COEFFICIENT OF RESISTANCE CONNECTED IN SHUNT RELATIONSHIP WITH RESPECT TO SAID SECOND TEMPERATURE-SENSITIVE RESISTOR BETWEEN THE JUNCTION OF SAID PAIR ADJACENT TO SAID SECOND TEMPERATURESENSITIVE RESISTOR AND SAID COMMON TERMINAL OF SAID POWER SOURCE AND VOLTAGE INDICATING MEANS CONNECTED ACROSS THE TAPS OF SAID VOLTAGE DIVIDERS, THE RESISTANCE VALUES OF SAID LOAD RESISTORS BEING PRESELECTED SO AS TO EFFECT A CONCURRENT COMPENSATION FOR POWER SUPPLY VOLTAGE AND AMBIENT TEMPERATURE FLUCTUATIONS ENCOUNTERED DURING SAID CHROMATOGRAPHIC ANALYSIS, AND THE TAPS OF SAID FIRST VOLTAGE DIVIDER AND SAID SECOND VOLTAGE DIVIDED BEING POSITIONED PRIOR TO COMMENCEMENT OF ANALYSIS WITH RESPECT TO THE ASSOCIATED DIVIDER RESISTORS SO AS TO EFFECT A NULLING OF THE NET VOLTAGE OUTPUT OF SAID BRIDGE WHEN SAID FIRST AND SAID SECOND TEMPERATURE-SENSITIVE RESISTORS ARE EXPOSED TO THE SAME ENVIRONMENT AND AMBIENT TEMPERATURE.