DE1473206

1,095,476. Measuring fluid-flow electrically. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Oct.2, 1964 [Oct. 17, 1963], No.41034/63. Heading G1N. The rate of flow of a fluid is determined from the phase difference in the response signals of two similar thermally sensitive elements, e.g. thermocouples, separated by a known distance in the direction of flow to thermal fluctuations of a predetermined frequency, selected by a narrow band filter. In another form of flowmeter, two thermocouples with dissimilar time constants are located at the same location and the phase difference in their response signals to a selected frequency component indicates the rate of flow by reference to a predetermined relationship. The two thermocouples are mounted in a common probe, with one thermally shielded to make the time constants different. It is stated that the rate of flow may be determined by measuring the time constant of a single thermocouple, e.g. by measuring the delay at different frequencies.