Apparatus for measuring a fluid

An apparatus (1) for measuring a flow of fluid (F) present and circulating inside a pipe, the apparatus comprising:

• a first containment casing (7) provided with a first opening (9) for the inlet of a fluid flow inside it and a second opening (11) for the fluid outlet,
• an electronic processing and/or control unit (25),
• at least a first absolute pressure sensor (2) which is arranged and configured to detect at least a first absolute pressure measurement PAF of said fluid (F) which crosses and/or circulates in said first enclosure (7) and sends to said unit electronics (25) at least one first electronic signal containing and/or representative of the first PAF,
• at least a second absolute pressure sensor (14) which is arranged and configured to detect at least a second absolute pressure measurement PAA of an external environment (A), in which said equipment is intended to be installed, and send to said electronic unit (25) at least one second electronic signal containing and/or representative of the second measurement PAA,
• at least a first temperature sensor (4) which is arranged and configured to detect a first temperature measurement TF of said fluid (F) and to send to said electronic unit (25) at least a third electronic signal containing and/or representative of said first temperature measurement TF,
• at least a second temperature sensor (20) which is arranged and configured to detect a second temperature measurement TA of said external environment (A) and to send to said electronic unit (25) at least a fourth electronic signal containing and/or representative of said second temperature measurement TA,
• said electronic processing and/or control unit (25) is electronically connected to said first absolute pressure sensor (2), to said second absolute pressure sensor (14), to said first temperature sensor (4) and to said second temperature sensor (20), to receive so-called corresponding electronic signals detected by said sensors
• said electronic unit (25) comprises at least one processing module configured to receive the corresponding electronic signals containing and/or representative of the first absolute pressure measurement PAF of said fluid (F), of the second absolute pressure measurement PAA of the external environment (A), of said first temperature measurement TF of said fluid (F), of said second temperature measurement TA of said external environment (A), said processing module being also configured for:
• adapting the value of said first absolute pressure measurement PAF of said fluid (F) on the basis of said first temperature measurement TF of said fluid (F),
• adapt the value of said second absolute pressure measurement PAA of said external environment (A) on the basis of said second temperature measurement TA of said external environment (A),
• calculate a relative pressure value PR of said fluid (F) using said first measurement of absolute pressure PAF of said fluid (F), which is adapted on the basis of said first temperature measurement TF, and using said second measurement of absolute pressure PAA of said external environment (A), which is adapted on the basis of said first temperature measurement TA,
• also calculating a volume value of said fluid (F) on the basis of said first temperature measurement TF of said fluid (F) and of said first absolute pressure measurement PAF of said fluid (F).