摘要:
In a method for determining mass-flow with the aid of a Coriolis mass-flow meter in which mass-flow ({dot over (m)}) is won from the phase difference of two sensor signals X17, X18, three measuring channels K1, K2, K3 are provided for the two sensor signals X17, X18. By selective switching of the sensor signals X17, X18 onto the measuring channels K1, K2, K3, phase error caused by the different signal paths can be determined and taken into consideration when calculating mass-flow ({dot over (m)}).
摘要:
In a method for determining mass-flow with the aid of a Coriolis mass-flow meter in which mass-flow ({dot over (m)}) is won from the phase difference of two sensor signals X17, X18, three measuring channels K1, K2, K3 are provided for the two sensor signals X17, X18. By selective switching of the sensor signals X17, X18 onto the measuring channels K1, K2, K3, phase error caused by the different signal paths can be determined and taken into consideration when calculating mass-flow ({dot over (m)}).
摘要:
A vibration meter and a method of measuring a viscosity of a fluid flowing through a pipe are disclosed. The vibration meter comprises meter electronics and a transducer assembly with an electromechanical excitation arrangement and with a flow tube which oscillates in operation. A sensor arrangement produces sensor signals representative of inlet-side and outlet-side deflections of the flow tube. An evaluation circuit derives from said sensor signals and from an excitation current generated by an excitation circuit for the excitation arrangement a viscosity value representative of the viscosity of the fluid.
摘要:
An apparatus for monitoring a measurement transmitter of a field device determining and/or monitoring a physical and/or chemical process parameter, wherein at least one sensor is provided inside a housing, in which the transmitter is arranged. The sensor determines the temperature and relative humidity in the housing over a period of time in predetermined intervals, and a control-/evaluation-unit is provided, which, on the basis of the measured temperature and relative humidity, determines the absolute humidity and/or the dewpoint in the housing of the transmitter, and issues and alarm when the absolute humidity and/or the dewpoint in the housing of the transmitter reaches a critical value.
摘要:
A vibration meter and a method of measuring a viscosity of a fluid flowing through a pipe are disclosed. The vibration meter comprises meter electronics and a transducer assembly with an electromechanical excitation arrangement and with a flow tube which oscillates in operation. A sensor arrangement produces sensor signals representative of inlet-side and outlet-side deflections of the flow tube. An evaluation circuit derives from said sensor signals and from an excitation current generated by an excitation circuit for the excitation arrangement a viscosity value representative of the viscosity of the fluid.
摘要:
To ascertain the mass-flow of a Coriolis mass-flow meter, an oscillation of a measuring tube is produced with the frequency f and the resulting oscillatory movement is registered at two different measuring points with two oscillation sensors. The analog sensor signals X17, X18 of the two oscillation sensors are converted into digital sensor signals S1 and S2 and further processed in a digital signal processor DSP. In the signal processor DSP, the sum signal Σ and the difference signal Δ are formed from the two sensor signals S1 and S2. Then the sum signal is rotated by 90°. In a further method step, the shifted sum signal is multiplied with the difference signal Δ. After ascertaining the amplitude of the sum signal Σ, the mass-flow is ascertained using the formula {dot over (m)}˜|Im(Δ)|/(|Σ|f). It is not necessary for the method, that the two sensor signals S1, S2 have equal amplitudes. Thus, a controlling of the analog signals X17, X18 to equal amplitudes can be omitted.
摘要:
A vibration meter and a method of measuring a viscosity of a fluid flowing through a pipe are disclosed. The vibration meter comprises meter electronics and a transducer assembly with an electromechanical excitation arrangement and with a flow tube which oscillates in operation. A sensor arrangement produces sensor signals representative of inlet-side and outlet-side deflections of the flow tube. An evaluation circuit derives from said sensor signals and from an excitation current generated by an excitation circuit for the excitation arrangement a viscosity value representative of the viscosity of the fluid.
摘要:
An apparatus for monitoring a measurement transmitter of a field device determining and/or monitoring a physical and/or chemical process parameter, wherein at least one sensor is provided inside the a housing, in which the transmitter is arranged. The sensor determines the temperature and relative humidity in the housing over a period of time in predetermined intervals, and a control-/evaluation-unit is provided, which, on the basis of the measured temperature and relative humidity, determines the absolute humidity and/or the dewpoint in the housing of the transmitter, and issues and alarm when the absolute humidity and/or the dewpoint in the housing of the transmitter reaches a critical value.
摘要:
The measurement transducer includes at least two oscillatably held transducer tubes vibrating, at least at times, during operation, of which at least one transducer tube serving to convey at least a volume portion of a medium to be measured, communicates with a pipeline; as well as at least one transducer element for converting electrical energy into mechanical and/or vice versa. The two transducer tubes are mechanically coupled together by means of at least one, inlet-side, coupling element and by means of at least one, outlet-side, coupling element in such a manner that both the inlet-side coupling element, as well as also the outlet-side coupling element, are subjected during operation repeatedly to deformations which correspond to vibrations of at least one of the two transducer tubes for converting electrical energy into mechanical, oscillatory energy and/or vice versa. The transducer element, especially a transducer element formed by means of a piezoelectric, deformation body, and at least one of the coupling elements, are, at least mediately, mechanically coupled together in such a manner that the transducer element executes, at least in part, oscillatory movements, which correspond with the repeated deformations at least of this coupling element.
摘要:
According to the invention, a digital processor (DSP) is provided in a measuring and operating circuit for a Coriolis-type mass flowmeter. From the vibration sensor signals, said digital processor evaluates only the differential signal (D) and the one sensor signal (S1). The in-phase component (I) and the quadrature components (Q) are determined for the differential signal (D), and the amplification of the second sensor signal (S2) is controlled in such a manner that the in-phase component (I) vanishes. The mass flow rate (m) is determined from the quadrature component (Q).