Measuring device, especially for a heating/air-conditioning installation

A Measuring device for a heating/air-conditioning installation, comprising sensors biased by at least one electrical power-supply source, wherein said measuring device further comprises at least one series branch (D1, D2, CT1, CT2) featuring a first and a second terminal coupled to terminals of said power-supply source, said series branch comprising a first (D1) and a second (D2) diode head to tail connected between the first (2) and the second (3) terminal of the series branch (D1, D2, CT1, CT2), and a first (CT1) and a second (CT2) sensor connected in series between the first (2) and the second (3) terminal of the series branch, wherein the common point between the first (D1) and the second (D2) diode is connected to the common point between the first (CT1) and the second (CT2) sensors, and a changeover-switching device for reversing the direction of the said bias so that the first (CT1) or the second (CT2) sensor is traversed by a current.