A method for operating a Coriolis mass flowmeter includes: calculating error-free oscillation signal phase differences using a first measuring channel pair with a first measuring channel phase difference; calculating averaged error-containing oscillation signal phase differences using a second measuring channel pair with a second measuring channel phase difference; determining error-containing oscillation signal phase differences using a third measuring channel pair with negligible measuring channel phase difference; determining the second measuring channel phase difference by difference formation from the averaged error-containing oscillation signal phase differences of the second measuring channel pair and the error-free oscillation signal phase differences of the first measuring channel pair; obtaining error-free oscillation signal phase differences by subtracting the determined second measuring channel phase difference from the error-containing oscillation signal phase differences of the third measuring channel pair; and using the error-free oscillation signal phase differences for determining the mass flow rate.

An apparatus and method of decreasing vibrational sensitivity of strain based measurements of fluid flow parameters for a fluid flow in a conduit is provided. The method includes using at least one vibrational sensor to sense a conduit to determine vibrational characteristics of the conduit, determining a predominant elastic axis using the measured vibrational characteristics, and securing a strain sensor array to an outer surface of the conduit, the strain sensor array having a plurality of strain sensors disposed at different axial positions of the conduit, the strain sensor array secured to the outer surface of the conduit at a position so that the strain sensor array is oriented substantially symmetric to the determined predominant elastic axis.

A measuring system includes a measuring and operation electronic unit (ME) and a transducer device electrically coupled thereto. The transducer device (MW) has at least one tube, through which fluid flows during operation and which is caused to vibrate meanwhile, a vibration exciter, two vibration sensors for generating vibration signals, and two temperature sensors for generating temperature measurement signals (θ1, θ2). The temperature sensors are coupled to a wall of the tube in a thermally conductive manner. The ME is designed to feed electrical power into the at least one vibration exciter to cause mechanical vibrations of the tube by an electrical excitation signal. The ME generates a mass flow sequence representing the instantaneous mass flow rate (m) of the fluid, so that, at least for a reference mass flow rate, the mass flow measurement values are independent of the temperature difference.

An apparatus and method of decreasing vibrational sensitivity of strain based measurements of fluid flow parameters for a fluid flow in a conduit is provided. The method includes using at least one vibrational sensor to sense a conduit to determine vibrational characteristics of the conduit, determining a predominant elastic axis using the measured vibrational characteristics, and securing a strain sensor array to an outer surface of the conduit, the strain sensor array having a plurality of strain sensors disposed at different axial positions of the conduit, the strain sensor array secured to the outer surface of the conduit at a position so that the strain sensor array is oriented substantially symmetric to the determined predominant elastic axis.

A measuring system comprises a measuring transducer of vibration-type having a tube arrangement, an exciter arrangement, a sensor arrangement, and a measuring system electronics. The measuring system electronics is adapted in a first operating mode to supply current to the oscillation exciters whereby the tube arrangement executes wanted oscillations with an oscillation frequency predetermined by the driver signals and to receive and to evaluate oscillation measurement signals representing oscillatory movements of the wanted oscillations. The measuring system electronics is further adapted in a second operating mode to supply current to the oscillation exciters that only the tube executes wanted oscillations and the tube executes no wanted oscillations while nevertheless executing mechanical oscillations coupled with the wanted oscillations of the tube and to receive and to evaluate both oscillation measurement signals representing oscillatory movements of the wanted oscillations and also oscillation measurement signals representing oscillatory movements of the coupled oscillations.

A fluid delivery system includes N first valves. Inlets of the N first valves are fluidly connected to N gas sources, respectively, where N is an integer greater than zero. N mass flow controllers include a microelectromechanical (MEMS) Coriolis flow sensor having an inlet in fluid communication with an outlet of a corresponding one of the N first valves. A second valve has an inlet in fluid communication with an outlet of the MEMS Coriolis flow sensor and an outlet supplying fluid to treat a substrate arranged in a processing chamber. A controller in communication with the MEMS Coriolis flow sensor is configured to determine at least one of a mass flow rate and a density of fluid flowing through the MEMS Coriolis flow sensor.

A Coriolis mass flowmeter having at least one measuring tube with at least one oscillation generator and at least two oscillation sensors and having at least two node elements. The at least one oscillation generator excites the measuring tube to oscillation during operation. The at least two node elements define the oscillation range. At least one node element has at least one stiffening element. An effective separation of undesired interference oscillations of the measuring tube is achieved by the at least one stiffening element increasing the stiffness of the measuring tube with respect to oscillations orthogonal to the excitation mode and to the Coriolis mode so that, during operation, the oscillation frequency of the oscillation orthogonal to the excitation mode and to the Coriolis mode is greater than the oscillation frequency of the excitation mode, preferably greater than that of the Coriolis mode.

An apparatus for measuring a parameter of a fluid flow passing within a pipe is provided. The apparatus includes a sensing device and a processing unit. The sensing device has a sensor array that includes at least one first macro fiber composite (MFC) strain sensor disposed at a first axial position, and at least one second MFC strain sensor disposed at a second axial position. The first axial position and the second axial position are spaced apart from one another. The at least one first MFC strain sensor and the at least one second MFC strain sensor are both configured to produce signals representative of pressure variations of the fluid flow passing within the pipe. The processing unit is configured to receive the signals from the sensor array and measure one or more fluid flow parameters based on the signals.

A system and method of maintaining back pressure located downstream of the Coriolis meter maintains the pressure downstream of the Coriolis meter in relation to the surface back pressure (SBP). At least one flow control device is located downstream of the Coriolis meter. The flow control device of the present invention (the BPV) automatically maintains the downstream pressure to less than or equal to fifty percent (50%) of the surface back pressure. A pressure regulator sets the back pressure to allow for a standalone device. Additional valves allow adjustment of the back pressure and allow for pressure relief and full flow bypass.

The invention relates to a measuring system comprising a measuring and operation electronic unit (ME) and a transducer device electrically coupled thereto. The transducer device (MW) has at least one tube, through which fluid flows during operation and which is caused to vibrate meanwhile, a vibration exciter (41), two vibration sensors (51, 52), on the inlet and outlet sides, respectively, for generating vibration signals (s1, s2), and two temperature sensors (71, 72), on the inlet and outlet sides, respectively, for generating temperature measurement signals (81, 82), said temperature sensors being coupled to a wall of the tube in a thermally conductive manner. The measuring and operation electronic unit (ME) is electrically connected to each of the vibration sensors (51, 52) and to each of the temperature sensors (71, 72) and also to the at least one vibration exciter (41). The measuring and operation electronic unit (ME) is designed to feed electrical power into the at least one vibration exciter (41) in order to effect mechanical vibrations of the tube (11) by means an electrical excitation signal (e1). Furthermore, the measuring and operation electronic unit (ME) is designed to generate a mass flow sequence (X.sub.m), namely a series of temporally successive mass flow measurement values (x.sub.m,i) representing the instantaneous mass flow rate (m) of the fluid, by means of each of the vibration signals (s1, s2) and each of the temperature measurement signals (1, 2) in such a way that, at least for a reference mass flow rate (m.sub.ref), namely a specified mass flow rate of a reference fluid flowing through the transducer device, the mass flow measurement values (x.sub.m,i.fwdarw.x.sub.m,ref) are independent of the temperature difference ().