Coriolis Mass Flow Meter Lab Report

Abstract This is an experiment about procedures of calibration of a Coriolis mass flow meter. To do the experiment, water is pumped from a reservoir and its flow rate is set by a tap, the height drop is examined by eye and the time is recorded for a period during the flow. This procedure is arranged for the calibration of the Coriolis meter by comparing the calculated mass flow and the read value. Although, it is a reasonable aspect for the calibration which is comparing digital and analog measurement methods, the control mechanism of the experiment, in this case human eye and a ruler placed on the transparent reservoir could give erroneous results. In the report, it is also discussed how this kind of errors could be fixed and what solutions
Each coriolis flow meter contains a tube and an exciter that makes this tube to oscillate constantly. These parts can be seen from the figure 3. Figure 3: Different aspects of a coriolis mass flow meter When there is no flow in the pipe the measuring tube oscillates uniformly. In addition, sensors are located at the inlet and the outlet of the tube. These sensors have ability to notice this basic oscillation perfectly when the fluid starts to flow in the measuring tube. Additional twisting is applied on the oscillation because of the liquids inertia. As a result of Coriolis Effect, the inlet and the outlet parts of the tube oscillate in different directions simultaneously. These very sensitive sensors gather this change in the tube oscillation in terms of time and space that is called the phase shift. How much liquid or gas is flowing through the pipe can be measured using this phase shift. The higher flow velocity and therefore the total flow, the greater the deflection of the oscillating measuring tube. A typical coriolis mass flow meter can measure not only mass flow but also volume flow, density, temperature, and viscosity with the help of these extremely sensitive
Assuming that C_u has negligible effect on the equation and knowing that Ω is the angular velocity of the vibrating tube that can be shown using following equation:
Ω=〖Ω 〗_(0 ) cos⁡ωt (5)
Equation (4) can be solved using information above and this particular solution is obtained: θ=θ_0 cos⁡ωt = (2K〖〖Ω 〗_(0 ) Q〗_m dl)/(K_u-I_u ω^2 ) cos⁡ωt (6)
Moreover, there is a time lag between two sides of the tube and it can be found from velocity over displacement such that τ=(θ_0 d)/(Ω_0 l)=(2KQ_m d^2)/(K_u-I_u ω^2 ) (7)
Then, the equation for mass flow rate can be obtained after measuring the time lag and the equation is :
Q_m=(K_u-I_u ω^2)/(2Kd^2 ) τ (8)
Experimental Setup &