Process variable e.g. concentration, determining method for biogas, involves measuring volume flow rate of flowing medium by using measuring principles, and determining process variable from measured values of measuring principles

摘要

#CMT# #/CMT# The method involves measuring volume flow rate of a flowing medium (3) i.e. biogas, by using a measuring principle e.g. thermal flow rate measurement, which is independent of a process variable e.g. concentration, of the medium. The volume flow rate of the medium is measured by using another measuring principle e.g. ultrasonic flow rate measurement, which is based on the process variable. The process variable is determined from measured values of the measuring principles. Additional variables e.g. pressure, are measured under same measuring conditions. #CMT# : #/CMT# An independent claim is also included for a system for determining a process variable of a flowing medium. #CMT#USE : #/CMT# Method for determining a process variable e.g. concentration or density, of a flowing medium i.e. biogas. #CMT#ADVANTAGE : #/CMT# The method can determine both the concentration and density of the flowing medium in an improved manner with reduced complexity and at reduced installation-, maintenance- and repair costs. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a block diagram of a system for determining a process variable of a flowing medium. 1 : Pipeline 2 : Evaluation unit 3 : Flowing medium 4 : Process variable determining system 5 : Ultrasonic flow rate measuring device.