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The participant knows… • … the different applications for level measurement • …the different technologies for level measurement • …which technologies are being used for the training rig • …th h i i f h h l i e characteristics of the used technologies The participant understand… • … each measurement technology has strength and weaknesses • …application and process conditions are very important
Products Solutions Level Measurement Slide / 85 13 October 2015 GBO Services Level Learning objectives The participant knows… • • • • … the different applications for level measurement …the different technologies for level measurement …which technologies are being used for the training rig …the h characteristics h i i off the h used technologies h l i The participant understand… • … each measurement technology has strength and weaknesses • …application and process conditions are very important Slide / 85 13 October 2015 GBO Level Applications with Level Device Level measurement applications in liquids including liquefied gases and bulk solids are divided into four areas: • • • • Continuous Measurement Point Level Detection D Density it Interface measurement Slide / 85 13 October 2015 GBO Level Applications with Level Device The overview contains the measuring principles suitable for each area Slide / 85 13 October 2015 GBO Level Finding the solution • The first step in finding a solution for a level metering point is finding g the best suitable measuring g technology gy • The selection is based on the requirements of the measuring point e.g.: Slide / 85 13 October 2015 GBO Level Influences on the selection of the measuring system Following can have an influence on the device selection • • • • • • Instrument accuracy Measuring range Application limits Process temperature Process pressure Process connection Slide / 85 13 October 2015 GBO Level Influences on the selection of the measuring system Slide / 85 13 October 2015 GBO Level Influences on the selection of the measuring system Slide / 85 13 October 2015 GBO Level Training Rig Level Measurement Technologies • Vibrating level detection • Capacitive level detection • Microwave level detection • Guided wave level detection • Ultrasonic level detection • Hydrostatic level detection Slide / 85 13 October 2015 GBO Products Solutions Level Measurement – Vibrating Level Detection Slide 10 / 85 13 October 2015 GBO Services Level Basics of Guided Radar level detection of the end of the m Slide 59 / 85 13 October 2015 GBO Level Basics of Guided Radar - Interface Measurement As the pulses impact the medium surface, only part of the sending pulse is reflected Especially in media with a low dielectric constant ,the other part penetrates the medium As the signal enters the lower medium with a higher dielectric constant it is reflected fl t d once more Taking T ki th the delayed Time-of-Flight of the pulse through the upper medium into consideration the distance to the interface is determined in addition Slide 60 / 85 13 October 2015 GBO Level Basics of Guided Radar - Interface Measurement The name of the innovation in interface measurement is FMP55 Multiparameter This instrument combines the advantages of the capacitance and guided radar measuring i principles i i l E l i Emulsion layers may cause signal losses in interface detection in g guided radar measurements Only Levelflex FMP55 Multiparameter can guarantee safe measured values for both the interface and the overall level with this unique, redundant measuring system Slide 61 / 85 13 October 2015 GBO Level Influences on the measuring system - DK Slide 62 / 85 13 October 2015 GBO Level Influences on the measuring system - DK Reflection signal of a micro impulse measurement with different media Slide 63 / 85 13 October 2015 GBO Level Advantages of guide radar level detection • Unaffected by medium surface (agitated surface, foam) • Unaffected ff by tank obstacles • Additional measuring safety through End of Probe (EOP) recognition • DK starting at 1.6 without stilling well (1.4 for coax probe) Slide 64 / 85 13 October 2015 GBO Level Disadvantages of guide radar level detection It is not Non-contact measurement anymore, Specially for solid application, check grain size etc Slide 65 / 85 13 October 2015 GBO Products Solutions Level Measurement – Ultrasonic Level Detection Slide 66 / 85 13 October 2015 GBO Services Level Basics of Ultrasonic level detection Functional principle : Ultrasonic pulses which are reflected from the medium surface by the density change between air and the medium The time between transmission and reception of the pulse is measured and analyzed by the instrument and provides a direct value for the distance between the sensor membrane and the medium surface Slide 67 / 85 13 October 2015 GBO Level Basics of Ultrasonic level detection What are ultrasonic waves? Sound = mechanical wave Air compression Air dilution Frequency of sound c λ= f Slide 68 / 85 13 October 2015 GBO c propagation velocity of mechanical wave (meter/second) λ wave length (meter) f frequency (Hertz) Level Influences on the measuring system Air moisture 0.3 % with change in relative l i moisture from to 100 % insignificant Temperature 17 % / °C 0.17 C measured and compensated Velocity of sound co = 331.6 m/s (1088 ft/s) Pressure change 30 bar / 435 p psi change in run time approx 0.3 % pmin = 700 mbar / 10 psi Dust !!! Wind !!! insignificant Foam !!! x • Rm (273 + T) c= M c: velocity of sound [m/s] Rm: universal gas constant (8314,3 J/kmol k) T: temperature [°C] x: adiabatic index M: molecular weight M cair at 20°C = 1.4 • 8314.3 • (273+20) Condensation !!! = Vacuum !!! Slide 69 / 85 13 October 2015 = 344 m //s (filling) noise !!! GBO 28.8 Gas layer !!! Level Influences on the measuring system Application limits for ultrasonic level measurement • Strong temperature fluctuations in the measuring range can affect the accuracy • p 50mbar • Surface of liquid Slide 70 / 85 13 October 2015 GBO Level Advantages of ultrasonic level detection • Non-contact, maintenance-free measurement • Unaffected by product properties, e.g DK value, etc • Calibration without filling or discharging • Easy and fast commissioning due to preset application parameters • Quick and simple commissioning via menu-guided onsite operation with envelope curves on the on-site display for simple diagnosis • Linearization function (up p to 32 p points) for conversion of the measured value into any unit of length, volume or flow rate Slide 71 / 85 13 October 2015 GBO Level Disadvantages of ultrasonic level detection • Affected by temperature changes , temperature compensation necessary • Affected by dust • Affected by pressure Slide 72 / 85 13 October 2015 GBO Level Conclusion • Unfortunately, a single-level measurement technology, is not good enough…… enough • Best level measurement technology would be very different,, according g to application pp Slide 73 / 85 13 October 2015 GBO ... Rig Level Measurement Technologies • Vibrating level detection • Capacitive level detection • Microwave level detection • Guided wave level detection • Ultrasonic level detection • Hydrostatic level. .. GBO Products Solutions Level Measurement – Capacitance Level Detection Slide 17 / 85 13 October 2015 GBO Services Level Basics of Capacitance level detection Capacitance measurement is based on... Accurate measurement in small vessels Slide 24 / 85 13 October 2015 GBO Level Capacitance level detection Slide 25 / 85 13 October 2015 GBO Products Solutions Level Measurement – Hydrostatic Level