Abstract: The first glass substrate having the first pressure admitting entrance for leading the pressure of fluid to be measured, is arranged at a side of a diaphragm of a pressure sensor, for measuring differential pressure. The second glass substrate is arranged at the side opposite to the first glass substrate, a spacer being sandwiched therebetween. The second pressure admitting entrance is formed at the second glass substrate, at the position opposite to the first presser admitting entrance of the first glass substrate. The first conductive film and the second conductive film are formed on two surfaces facing to each other, of the first and second glass substrates, respectively. By measuring the specific conductance and the dielectric constant of the object fluid between the two conductive films, these physical constants indicating the quality of the fluid, the quality of the fluid can be also detected.

Abstract: The invention provides a method of monitoring variation in the current value of a rate of fluid flow through a fluid meter which includes a measurement unit and a rotary shaft connected to said measurement unit and suitable for rotating about its own axis when a volume of fluid passes through the measurement unit, the method consisting in detecting rotary movements rather than rotation of the shaft at a sampling frequency that is variable in application of a predetermined sampling relationship, said frequency being defined as a function of at least one predetermined fluid flow rate value, and in electronically processing bits corresponding to detection and to non-detection of a rotary movement of the shaft at said sampling frequency in order to determine the current value of the fluid flow rate over a continuum of flow rates and relative to the predetermined fluid flow rate value included in said continuum of flow rates.