Patent ID: 8473224

Claim:
A flowmeter transmitter comprising: at least one processing device; and a storage device, the storage device storing instructions for causing the at least one processing device to: induce motion in a conduit such that the conduit oscillates in a first mode of vibration and a second mode of vibration, the first mode of vibration having a corresponding first frequency of vibration and the second mode of vibration having a corresponding second frequency of vibration, wherein the conduit contains fluid; determine at least one of the first frequency of vibration or the second frequency of vibration; calculate a property of the fluid based on the first frequency of vibration and the second frequency of vibration, wherein the first frequency is determined based on the second frequency by calculating: ω 1 2 = ω 2 2 ⁢ ( E 2 + ( E 2 - D 2 ) ⁢ t 2 ) 2 ( E 2 + ( D 4 - E 4 ) ⁢ t 2 ⁢ ω 2 2 ) ⁢ ( D 2 + ( D 4 - E 4 ) ⁢ ( 1 + t 2 ) ⁢ ω 2 2 ) where ω 1 is the first frequency, ω 2 is the second frequency, t 2 = k ⁢ ⁢ tan 2 ⁡ ( φ 2 ) where φ is the phase difference k, D 2 , D 4 , E 2 , and E 4 are calibration constants related to physical properties of the conduit, determine an augmented temperature, wherein the augmented temperature is calculated using: T f *=T f −k td1 ( T f −T m ), where T f , is the temperature of the fluid contained in the flowtube, T 0 is a reference temperature and the ambient temperature or flowtube temperature is T m , and k td2 is an empirically determined constant that is specific to the flowtube; update calibration constants E 2 , and E 4 using augmented temperature, wherein E is calculated using: E 2 =E 20 (1 +E ( T f *−T 0 )) E 4 =E 40 (1 +F ( T f *−T 0 )), determine a density compensated for effects of mass flow rate on frequencies by the calculation: ρ 0 = 1 2 ⁢ ( D 4 + E 4 + 4 ⁢ ⁢ D 2 ⁢ E 2 ω 1 2 ⁢ ω 2 2 + ( D 4 - E 4 ) 2 ) , where D 2 , D 4 , E 2 , and E 4 are calibration constants, and ω 1 is the Coriolis mode frequency, and ω 2 is the driven mode frequency.