Abstract: A method and apparatus for measuring mass flow rates and other characteristics of a fluid in a large conduit uses a sensor circuit having a heater/thermometer, a reference resistor, and a thermometer resistor arranged in four-wire network to enable measurement of all characteristics of the resistor network. That sensor circuit is preferably mounted on an interior wall surface of a support tube. A plurality of such support tubes, each having a plurality of sensors within the support tube, are mounted in an array in the cross section of the duct. A cleaning plate for cleaning the exterior surface of the support tube permits calibration of the network while cleaning. A program for using the circuit to calculate values of interest and to display desirable output data is also disclosed, as is a program for controlling the cleaning/calibration cycle.

Abstract: A method and apparatus for applying in rapid sequence excitation voltages of significantly different amplitude to a flow transducer having a resistive temperature sensor in circuit with a reference resistor, analyzing the resetting output signals from the flow transducer and reference resistor under the two states of excitation, and computing a physical characteristic of a material such as its mass flow rate through a conduit from those resulting output signals.