SOFTWARE AND METHODS FOR MASS FLOW METER COMPUTATION

摘要

Microprocessor-based thermal dispersion mass flow meters (i.e., thermal anemometers) are described that use temperature sensing elements in its flow sensor probe(s) in addition to the two elements commonly used. Such systems allow for automatically managing changes in gas selection, gas temperature, gas pressure, and outside temperature. One mass flow meter described has a flow sensor with four temperature sensing elements, wherein one pair is provided in a temperature sensor probe and another pair in a velocity sensor probe. Another variation operates without a separate temperature sensor probe and integrates all function into a single three-sensor probe. Such a device may also be used in conjunction with a one- or two-sensor temperature probe.

主权项

1. A computer readable medium having stored thereon instructions, which when executed cause one or more processors to:
receive input signals corresponding to two or more temperature measurements from a velocity probe including a heated sensor and a secondary temperature sensor spaced apart from the heated sensor by a distance no greater than three times a diameter of the velocity probe, the two or more temperature measurements including a first measurement obtained from the heated sensor and a second measurement obtained from the secondary temperature sensor; calculate a mass flow rate using the first measurement and the second measurement, wherein the calculating is based on a computational model corresponding to a relationship of heat conduction and convection in the velocity probe relative to electrical power supplied to the heated sensor of the velocity probe, wherein the second measurement is used as a boundary condition in the computational model; and output an output signal corresponding to the calculated mass flow rate.