Differential pressure sensor comprising a symmetric error in the separating bodies

Abstract

A pressure-difference sensor, which is asymmetrical by design, includes a measuring apparatus having a first half-chamber with a first volume V, which is sealed by a first separating membrane having a first membrane stiffness E, and a second half-chamber with a second volume V, which is sealed by a second separating membrane having a second membrane stiffness E, wherein the first half-chamber is separated from the second half-chamber by a pressure sensitive element, especially a measuring membrane, and the first half-chamber is filled with a first transfer liquid having a first coefficient of thermal expansion αand the second half-chamber is filled with a transfer liquid having a second coefficient of thermal expansion α. For making the temperature-dependent, separating-membrane pressure-error dP symmetrical, the design is so embodied that a first product of the first membrane stiffness, the first volume and the first coefficient of thermal expansion is essentially equal to a second product of the second membrane stiffness, the second volume and the second coefficient of thermal expansion (E*V*α=E*V*α), wherein, additionally, at least one factor of the first product deviates, by design, from the corresponding factor of the second product.