Nufiqurakhmah1, Laksana Angga Widoto2 1Engineering Physics, Sepuluh NopemberInstitute of Technology

Surabaya, Indonesia 1nufiqurakhmah@mhs.ep.its.ac.id

2 Human Resources Development Centre of Metrology Bandung, Indonesia

2anggawidoto@gmail.com

Abstract— Measurement of flow rate is an important

parameter in an industrial process. The instrument used is called a flow meter. Coriolis mass flow meter is one of the flow meter technologies are relatively new to utilizing the coriolis effect. Limited references and expensive price compared to other types of flow meters causing training on the working principle of the coriolis mass flow meter for metrology resources are still very limited. Meanwhile, many industries began using this instrument because of several advantages, including high rangeability and accuracy. Therefore, need a simulator demonstration coriolis mass flow meter for the benefit of education and training of skilled labor candidate metrology.

The focus of this paper is to show the working principle of the coriolis mass flow meter through the simulator demonstration. The simulator consists of several components, namely flow tube as a fluid flows, motor as a driver tube, and TCRT 5000 sensors to detect oscillation pattern of the inlet and outlet tube. Results obtained in the form of a voltage value that is sent through the PLX-DAQ software and visualized in graphical form.

Keywords—flow rate; the coriolis effect; coriolis mass flow meter, simulator demonstration

I. INTRODUCTION

Flow rate measurement using a flow meter instrument in the industry is divided into two types, that mass and volumetric. Some of the information flow meter with volumetric flow rate as the differential pressure flow meter, turbine flow meter, and positive displacement flow meter has been widely applied in industry. However, compared to this types, flow meter with a mass flow rate has several advantages including not depend on the flow profile, viscosity, and fluid density.

One type of flow meter with flow rate mass is coriolis mass flow meter (taken from the French civil engineer, Gustave Gaspard Coriolis). Physically, the coriolis mass flow meter consists of a pipe which is bent as primary element, driven by the drive coil as driver elements. Coriolis mass flow meter works by interfering the flow of the fluid flowing

through the flow tube. The flow in this tube causes phase difference between inlet and outlet. The resulting phase difference will be proportional to the mass flow rate of fluid particles. However, elements of the coriolis mass flow meter are shrouded in a casing, so that the working principle of this flow meter could not be observed directly.

In Indonesia, coriolis mass flow meter is still relatively new when compared to other types of flow meters. Expensive prices and limited references lead training on the working principle of the coriolis mass flow meter is still difficult. On the other hand, many industries have started using the coriolis mass flow meter to measure the flow rate of fluid, such as oil & gas industry, pharmaceutical, and food industries. Therefore, it necessary an instrument as working-principle illustrator of coriolis mass flow meter. This paper describes the design of a simulator demonstration coriolis mass flow eter that developed can provide important information in the form of variation deviation indicator on both sides of the tube due to the mass of the fluid particles move.

II. THE PRINCIPLE OF FLUID FLOW MEASUREMENT OF

CORIOLIS MASS FLOW METER

Coriolis effect is defined as the phenomenon of deflection (deflection direction) motion of an object in a rotating frame of reference. Coriolis effect gave rise to an internal forces due to the rotation of particles in a rotating motion, which is called the coriolis force. The principle of measurement of coriolis mass flow meter utilizes the coriolis force that appears in the system that rotates and oscillates (vibrates). Fluid passing through the vibrating tube is forced to have a transverse acceleration as it moves towards the peak amplitude of vibration. When moving away from the amplitude of vibration, acceleration will be reduced. This shows the phase difference. The phase difference is proportional to the mass flow rate.

Simulator of Fluid Flow Measurement with Coriolis Effect for Education and Training of

Metrology

Fig. 1. Measurement Principal of Coriolis Mass Flow Meter[1]

As the system shown in Fig. 1 for a straight-tube, flow tube subjected external force FE. FE derived from driver element (drive coil) which causes the flow tube vibrates at a certain frequency excitation. Excitation frequency is at a natural frequency of the flow tube, which minimize the energy required for the vibrating of flow tube. Mathematically, the general equation of coriolis force (FC) is expressed as :

Fc = 2 • m • v × ω (1) with q = m • v is mass flow rate and ω is vector rotation.[1]

When fluid is not flowing in the vibrated flow tube, the coriolis force working equal to zero (Fc = 0). When the fluid begins to flow in the flow tube, the coriolis force will arise due to the velocity of the fluid particles in a rotating motion (Fc ≠ 0). At the inlet, the coriolis force tends to slow down the movement of the vibrating flow tube. However, at the outlet, the coriolis force tends to accelerate the movement of the vibrating flow tube. When the fluid begins to flow, the coriolis force will cause a phase shift along the flow tube. The phase shift is proportional to the mass flow rate. The magnitude of the mass flow rate can be calculated by measuring the phase shift between the two position sensors, S1 and S2.

[1]

III. DESCRIPTION OF FLUID FLOW MEASUREMENT SYSTEM

SIMULATOR WITH CORIOLIS EFFECT

Components of coriolis mass flow meter consists of flow tube, drive coil, and pickoff coil. In designs, components that used are different with the actual instrument but can display the function of coriolis mass flow meter.

Table 1. Comparison of CMF Instrument and Prototype Simulator of CMF

Componen CMF Instrument Prototype Simulator

Primary elemnt (flow tube)

Composing materials including stainless steel, Hastelloy, and tantalum

Material frrom milliard hose (plastic material)

Driver element

Drive coil, consist of magnet and coil that placed on the opposite

Form of two magnet

tube

Sensor Magnetic sensor (electrodynamic pickup), detect the phasa shift or time lag in inlet and outlet.

Optic sensor (TCRT 5000), detect the patterns of oscillation in inlet and outlet.

Fig. 2. Prototype Simulator Fluid Flow Measurement with Coriolis Effect and its Parts

a. Holder (dudukan) : as a place of primary element (flow

tube) and driver element (motor servo). Wooden holder

used with dimensions of 60 cm × 20 cm × 40 cm and a

thickness of 1 cm.

b. Servo arm trajectories (lintasan lengan motor servo) : a

straight line with the dimensions of 5 cm × 10 cm to

convert rotational motion into translational motion.

c. Primary elements (elemen primer) : a flow tube, as the

flow of the fluid phase difference will be observed on the

inlet and outlet. The primary elements used were form

milliard hose with arch 80 cm long, 3/8 inch in diameter,

and thickness of 0.3 cm. Considerations for selecting hose

milliard which includes plastic material as the primary

element of the prototype is a test performed at a low flow

rate.

d. Driver elements (elemen driver) : a servo motor with an

arm length used was 12 cm and the two magnets are

mutually interacted. Both magnets are a magnetic hard

drive (on the arm servo motor) and neodymium magnet

material (in the middle of the primary elements). Both

magnets interacted to mutually repel. The experiments

results based on good combination of the two magnets is 4

cm.

e. TCRT 5000 Sensor (sensor TCRT 5000) : is optical sensor,

as a proximity sensor that measures the distance to the

object detectors based on the reflection of infrared light

from the transmitter is received by the receiver. TCRT

5000 sensors used to detect differences in the pattern of

oscillations on both sides of the primary element.

Based on datasheet[4], it is known that the working range of

the sensor is 0.2 mm up to 15 mm. Sensor results are not

linear outside range work. Therefore, to produce a linear

relationship between distance and voltage direction, it may

be desirable to limit the range of particular work. Working

range of the sensor is initially 0.2 mm to 15 mm narrowed

down to 2 mm to 16 mm.

f. Mikrokontroler : Arduino Uno, to adjust the servo arm

position, and process the TCRT 5000 sensor output and

display in the form of voltage levels.

IV. DATA AND ANALYSIS

Tests carried out in the workshop Engineering Physics - ITB. Tests were conducted at three test points, the valve opening 0%, 50%, and 100%. The data output is displayed in the plots of voltage versus time.

Furthermore, statistical analysis is done by cross-correlation method to determine the differences in the oscillation pattern detection inlet and outlet of the primary elements of each test point. Cross-correlation method has two input variables. Letting the voltage level at the sensor 1 is the variable x and the voltage level at the sensor 2 is the variable y, then this method can be determined through the results of the cross-correlation Rxy. Cross-correlation coefficient has a range between 0 to 1. The close to 1 indicates no difference in the detection of deviation patterns on either side of the primary elements.

0 50 100 150 200 250 300 350 4000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Indeks Korelasi Silang Rxy

Nila

i K

ore

lasi S

ilang R

xy

Plot Korelasi Silang Level Tegangan Detektor 1 dan Detektor 2 untuk Tiap - Tiap Titik Uji

bukaan valve 0%

bukaan valve 50%

bukaan valve 100%

Fig. 3. Cross-Correlation Plot of Voltage Level of Sensor 1 and Sensor 2

Based on Fig. 3 maximum cross-correlation value (Rxy-max ) is at valve opening 0% (red - value 0.7062), than 50% (green – value 0.8394), and 100% (blue - value 0.8474). The difference of Rxy-max at each test point indicates a difference in the pattern deviation detection which tends to shrink with increasing valve opening. This is contrary to the basic principle of the Coriolis mass flowmeter instruments, namely, as can be shown by the following mathematical equation (1).

The above equation (1) shows that the larger the mass flow rate, the particle mass (m) is contained in the greater fluid

flow. At the same oscillation frequency, the Coriolis force that increasingly large. As a result, the pattern of deviation on either side of the primary elements of the different

The coriolis force can also be indicated by a time lag (Δτ), according to the equation:

m = C • Δτ (2)

The equation shows that the more mass of fluid particles flowing, lag (Δτ) that occurs between the inlet and outlet sides of the primary elements getting bigger. Results of tests performed accordance with the basic theory, which there is a difference in the detection of oscillation pattern before and after the fluid flowing through the primary element. The difference in the detection of oscillation pattern indicates the influence of the coriolis force, although not quite representative. In the enlargement of valve opening, the lag is not likely to change significantly. This can be shown by the plot in Fig. 4, Fig. 5, and Fig. 6 as follows.

Fig. 4. Plot Data in a Full Wave of Opening Valve 0%

Fig. 5. Plot Data in a Full Wave of Opening Valve 50%

Fig. 6. Plot Data in a Full Wave of Opening Valve 100%

Table 2. Data Value of a Full Wave of Opening Valve

Opening Valve

Time (s) Sensor 1(V) Sensor 2 (V)

0%

2.075 3.84 3.80

2.675 0.25 0.34

2.7 0.23 0.35

2.95 3.81 3.80

50%

0.2 3.86 3.81

0.75 1.52 1.30

0.775 1.36 1.35

1.075 3.84 3.78

100%

0.35 3.84 3.84

0.95 1.45 1.37

0.975 1.42 1.66

1.225 3.85 3.80

Based on the data plot in Fig. 4, Fig. 5, and Fig. 6, it can be seen that less likely to happen changes in the value of the maximum voltage that can be reached by both sensor signal on each test point. Table 2 takes data from PLX DAQ show the value of tests performed in the consistent range of voltage value 3.50 V – 4.00 V. However, the value of the minimum voltage that can be reached by both sensors tend to increase with enlargement of valve opening. This is because the existing actuating mechanism oscillations that occur in the primary elements (flow tube) is only half full wave. When the servo arm moves forward, the primary element of the sensor will move closer to its initial position. However, when the servo arm moves backwards, the primary element will return to its original position and do not deviate in the opposite direction. Thus, if there is a lag between the two signals can only be observed when both the signal moves towards the minimum voltage level.

Differences were not significant lag between the two signals at the valve opening 50% and 100% can be caused by several factors.

a. Characteristics valve used is a type of quick opening. The

possibility of fluid flow velocity at the time of valve

opening 50% and 100% is relatively constant. It can be

shown from the range of the minimum voltage value at

both test points tend to be close together, that is 1.30 V –

1.36 V on opening valve 50% and 1.37 V – 1.42 V at

100% valve opening.

b. Not involve the natural frequency and the frequency of

the primary elements of the driving element.

c. Differences in characteristics of the two sensors based on

testing that has been done.

d. The primary elements of the material used were plastic

hose with a single design - tube so vulnerable affected by

external vibration. External vibration can be derived from

the floor or mechanical activity that takes place in the

area of testing. This causes the sensor is difficult to detect

any changes due to fluid mass flow.

e. he larger tube geometry (distance between the inlet and

outlet) causing zero-point is unstable due to external

interference increases. This causes the signal ratio to

noise are same.

V. CONCLUSION

Based on tests performed can be concluded as follows: a. Prototype simulator of fluid flow measurement with

Coriolis effects are made based on the Arduino Uno

microcontroller using TCRT 5000 sensors that are

integrated with Parallax Data Acquisition software

and spreadsheet application program for the

education and training of metrology.

b. 5000 TCRT sensor has the characteristics of non-

linear, but the linear state can be obtained by limiting

the measurement range.

c. The prototype simulator flow measurement with

Coriolis effects can already indicate a difference in

the detection of patterns of oscillation between the

two sides of the primary elements based on the value

of the maximum peak of the cross-correlation, ie

0.7062 (0% valve opening), 0.8394 (50% valve

opening), and 0.8474 (valve opening 100 %). The

larger the valve opening, the differences tend to be

smaller oscillation pattern detection.

d. The prototype simulator flow measurement with

Coriolis effects can differentiate the presence or

absence of fluid flow conditions based on the

presence or absence of lag. However, differences in

lag that occurs on the valve opening 50% and 100%

more likely to be insignificant.

REFERENCES

[1] Apple, Cathy; Anklin, Martin; Drahm, Wolfgang. 2003. Mass Flowmeters, Coriolis - Instrument Engineers’ Handbook: Process Measurement and Analysis, 4rd edition, Vol. 1.

[2] OMEGA Vol. 4 Flow and Level Measurement Handbook, Transaction in Measurement and Control, OMEGA Press.

[3] Abdulloh. Coriolis Meter. PT. Pertamina (Persero) RU V Balikpapan.

[4] Document Number: 83760 rev 1.7., TCRT 5000 Reflective Optical Sensor with Transistor Output, Vishay Semiconductor, 17 Agustus 2009.

[5] Fahy, Frank. 2003. Fondation of Engineering Acoustics. Great Britain: MPG Books Ltd, Cornwall, UK.

[6] Halliday, David; Resnick, Robert; Krane, Kenneth S. 1992. Physics 4rd edition. Canada: John Wiley & Sons, Inc. Chapter 37: Magnetic Properties of Matter (hal. 811 – 814).

[7] Kopp, J.G., D.J. Lomas, B.G Liptak, W.H. Boyes. 2003. Vortex and Fluidic Flowmeters - Instrument Engineers’ Handbook: Process Measurement and Analysis, 4rd edition, Vol. 1.

[8] Kurniadi, Deddy. “Slide Perkuliahan TF 3101 - Metode Pengukuran: Pengukuran Aliran”. Institut Teknologi Bandung, Bandung.

[9] Liptak, B.G., H.M. Hashemian. 2003. Cross-Correlation Flow Metering - Instrument Engineers’ Handbook: Process Measurement and Analysis, 4rd edition, Vol. 1.