Abstract
A flow meter (1) comprising a sampling tube (3) through which fluid may flow and a sensor arrangement (9, 25, 27, 39, 41, 43, 44, 45, 46, 47), wherein the sampling tube (3) comprises a first hollow section (51, 53) having a first internal cross-sectional area (A1) and a second hollow section (55, 57) having a second internal cross-sectional area (A2) being less than the first internal cross-sectional area (A1); and the sensor arrangement (9, 25, 27, 39, 41, 43, 44, 45, 46, 47), is for measuring the difference between stagnation and static pressures (P01, P02, P1, P2) within the second hollow section (55, 57).