METHOD FOR SIGNALLING A STANDARD FREQUENCY OF A DENSITY METER WHICH HAS AT LEAST ONE VIBRATABLE MEASUREMENT TUBE FOR CONDUCTING A MEDIUM

摘要

The method (300) according to the invention for signalling a standard frequency of a density meter which has at least one vibratable measurement tube for conducting a medium comprises: exciting (310) bending vibrations of the measurement tube in a bending vibration useful mode at a useful mode working frequency, the useful mode working frequency depending on the density of a medium conducted in the measurement tube and on at least one disturbance variable; determining (320) a characteristic value of the useful mode working frequency; determining (330) a value representing the disturbance variable; calculating (340) a correct density value of the medium as a function of the characteristic value of the useful mode working frequency and of the value representing the at least one disturbance variable; calculating (350) a characteristic value of the standard frequency as a function of the correct density value, the standard frequency being the frequency which produces the correct density value in a calculation of the density by means of a frequency-dependent standard function which is not dependent on the disturbance variable; and providing (360) a signal which represents the standard frequency.