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Seminar presentation

Students are required to present a seminar on the topic choosing from the II1 syllabus. The content of the seminar should be taken from world wide web with importance given to Industrial application and specifications.

A batch of not exceeding 5 students need to be formed and their names and titles are to be registered on or before 17 sep 2010 in the link given below.

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Selecting a flowmeter (Discussion)

SELECTING A FLOWMETER

Experts claim that over 75 percent of the flowmeters installed in industry are not performing satisfactorily. And improper selection accounts for 90 percent of these problems. Obviously, flowmeter selection is no job for amateurs.

The most important requirement is knowing exactly what the instrument is supposed to do. Here are some questions to consider. Is the measurement for process control (where repeatability is the major concern), or for accounting or custody transfer (where high accuracy is important)? Is local indication or a remote signal required? If a remote output is required, is it to be a proportional signal, or a contact closure to start or stop another device? Is the liquid viscous, clean, or a slurry? Is it electrically conductive? What is its specific gravity or density? What flow rates are involved in the application? What are the processes' operating temperatures and pressures? Accuracy (see glossary), range, linearity, repeatability, and piping requirements must also be considered.

It is just as important to know what a flowmeter cannot do as well as what it can do before a final selection is made. Each instrument has advantages and disadvantages, and the degree of performance satisfaction is directly related to how well an instrument's capabilities and shortcomings are matched to the application's requirements. Often, users have expectations of a flowmeter's performance that are not consistent with what the supplier has provided. Most suppliers are anxious to help customers pick the right flowmeter for a particular job. Many provide questionnaires, checklists, and specification sheets designed to obtain the critical information necessary to match the correct flowmeter to the job.

Technological improvements of flowmeters must be considered also. For example, a common mistake is to select a design that was most popular for a given application some years ago and to assume that it is still the best instrument for the job. Many changes and innovations may have occurred in recent years in the development of flowmeters for that particular application, making the choice much broader.

A recent development is the availability of computer programs to perform the tedious calculations often necessary for selecting flowmeters. Calculations that used to take an hour can be performed in a matter of seconds.

Cost Considerations

There are a wide range of prices for flowmeters. Rotameters are usually the least expensive, with some small-sized units available for less than $100. Mass flowmeters cost the most. Prices start at about $3500. However, total system costs must always be considered when selecting flowmeters. For example, an orifice plate may cost only about $50. But the transmitter may add an additional $500 or $600, and sensing line fabrication and installation may cost even more.

Installation, operation, and maintenance costs are important economic factors too. Servicing can be expensive on some of the more complicated designs.

As with many other products, a plant engineer generally gets what he pays for when he purchases a flowmeter. But the satisfaction that he receives with the product will depend on the care that he uses in selecting and installing the instrument. And that gets back to knowing the process, the products, and the flow-metering requirements. "Overbuying" is not uncommon. Plant engineers should not buy a flowmeter more capable or complicated than they need.

WORKING WITH FLOWMETERS

Although suppliers are always ready to provide flowmeter installation service, estimates are that approximately 75 percent of the users install their own equipment. But installation mistakes are made. One of the most common is not allowing sufficient upstream and downstream straight-run piping for the flowmeter.

Every design has a certain amount of tolerance to nonstable velocity conditions in the pipe, but all units require proper piping configurations to operate efficiently. Proper piping provides a normal flow pattern for the device. Without it, accuracy and performance are adversely affected. Flowmeters are also installed backwards on occasion (especially true with orifice plates). Pressure-sensing lines may be reversed too.

With electrical components, intrinsic safety is an important consideration in hazardous areas. Most flowmeter suppliers offer intrinsically safe designs for such uses.

Stray magnetic fields exist in most industrial plants. Power lines, relays, solenoids, transformers, motors, and generators all contribute their share of interference. Users must ensure themselves that the flowmeter they have selected is immune to such interference. Problems occur primarily with the electronic components in secondary elements, which must be protected. Strict adherence to the manufacturer's recommended installation practices will usually prevent such problems.

Calibration

All flowmeters require an initial calibration. Most of the time, the instrument is calibrated by the manufacturer for the specified service conditions. However, if qualified personnel are available in the plant, the user can perform his own calibrations.

The need to recalibrate depends to a great extent on how well the meter fits the application. Some liquids passing through flowmeters tend to be abrasive, erosive, or corrosive. In time, portions of the device will deteriorate sufficiently to affect performance. Some designs are more susceptible to damage than others. For example, wear of individual turbine blades will cause performance changes. If the application is critical, flowmeter accuracy should be checked at frequent intervals. In other cases, recalibration may not be necessary for years because the application is noncritical, or nothing will change the meter's performance. Some flowmeters require special equipment for calibration. Most manufacturers will provide such service in their plant or in the user's facility, where they will bring the equipment for on-site calibration.

Maintenance

A number of factors influence maintenance requirements and the life expectancy of flowmeters. The major factor, of course, is matching the right instrument to the particular application. Poorly selected devices invariably will cause problems at an early date. Flowmeters with no moving parts usually will require less attention than units with moving parts. But all flowmeters eventually require some kind of maintenance.

Primary elements in differential pressure flowmeters require extensive piping, valves, and fittings when they are connected to their secondary elements, so maintenance may be a recurring effort in such installations. Impulse lines can plug or corrode and have to be cleaned or replaced. And, improper location of the secondary element can result in measurement errors. Relocating the element can be expensive.

Flowmeters with moving parts require periodic internal inspection, especially if the liquid being metered is dirty or viscous. Installing filters ahead of such units will help minimize fouling and wear. Obstructionless instruments, such as ultrasonic or electromagnetic meters, may develop problems with their secondary element's electronic components. Pressure sensors associated with secondary elements should be periodically removed and inspected.

Applications where coatings may occur are also potential problems for obstructionless instruments such as magnetic or ultrasonic units. If the coating is insulating, the operation of magnetic flowmeters will ultimately be impaired if the electrodes are insulated from the liquid. This condition will be prevented by periodic cleaning. With ultrasonic flowmeters, refraction angles may change and the sonic energy absorbed by the coating will cause the meter to become inoperative.

Ultrasonic & Electromagnetic Flow-meters (3 August)

The learner will be able to the operation of

1. Ultrasonic Flow-meters
   
2. Electromagnetic Flow-meters
   
3. Types
4. Specifications
   
5. Pros and Cons
6. Applications
   

Turbine & Vortex Flowmters (2 August)

Objective

The learner will be able to the operation of

1. Turbine flow-meters
   
2. Vortex Flow-meters
3. Types
4. Specifications
   
5. Pros and Cons
6. Applications
   

Session 12 (23 July 2010)

Objectives:

The learner will be able to understand basics of flow measurement principles.

Understand:

1. Review of types of flow meters
   
2. Inferential type flow meters types
   
3. Variable head type operation and design specifications
4. Variable area type flow meter
   

Session 11 (22 July 2010)

Objectives:

The learner will be able to understand basics of flow measurement principles.

Understand:

1. Review of fundamentals
2. basic equations used for flow measurements
3. Different category of flow meters
4. Inferential type flowmeters
   

Tools

• Students explaining the principle of operation with their practical knowledge
• Analogy to explain the principle behind Inferential type flow meters

Session 10

Objectives:

The learner will be able to understand basics of flow measurement.

Understand:

1. what is velocity
2. different types of flow
3. usage of Reynolds No
4. Bernoulli principle
5. Viscosity and its importance
   
6. application of Bernoulli principle

Tools

Quiz program with three teams R1000, R3000 & R5000

Session 9

Objectives:

The learner will be able to understand different applications roughness measurements.

Understand:

* What is roughness?
* Typical roughness parameters
* Stylus, Optical & Microscopic techniques

Learners work:

Identify the industrial applications and typical specifications

Session 8 (16 July 2010)

Objectives:

The learner will be able to visually understand different applications of torque, force, straightness, roundness, roughness measurements.

Understand:

• Installation of strain gauges for torque measurement
  
• Laser Interferometry principles
• Dimensions measuring instruments and their calibration
  

Learners work:

Identify the industrial applications and typical specifications

Reference:

www.youtube.com

Session 7 (15 July 2010)

Objectives:

The learner will be able to identify the importance of Dimension measurements.

Understand:

• Importance of straightness measurement
• Different techniques available for Roundness & Roughness measurement
• Typical specifications
  

Learners work:

Identify the industrial applications and typical specifications

References:

• http://www.manmonthly.com.au/news/measuring-roundness-accurately
• http://www.coe.uncc.edu/~jraja/ProjectResources/Roundness_I.pdf
• http://en.wikipedia.org/wiki/Surface_roughness
• http://en.wikipedia.org/wiki/Waviness
• http://www.sjsu.edu/faculty/selvaduray/page/papers/mate210/surface.pdf
• http://www.ptb.de/en/org/5/51/517/rptb_web/doc/en/principle_of_roughness.pdf

Session 6 (14 July 2010)

Objectives:

The learner will be able to identify the importance of Dimension measurements.

Understand:

• Different parameters of Dimension measurements

1. Straightness
2. Flatness
3. Roundness
4. Roughness
   

• Importance of straightness measurement
• Different techniques available for straightness measurement
• Typical specifications
  

References:

1. http://www.damalini.com/Straightness-477.aspx
2. http://www.lapmaster.com/accessories/flatness-instruments/default.html
3. http://www.optodyne.it/CD/Italiano/Applicazioni/Ap1118%20Straightness%20and%20Squareness.pdf
4. http://www.slac.stanford.edu/econf/C951114/papers/047.PDF

Session 5

Objectives:

The learner will be able to identify the importance of speed measurement.

Understand:

• Speed measurement principles
  
• Different types of tachometers
• Stroboscopic techniques
• applications of stroboscopic methods and speed measurement

Work for learners:

• Identify speed measurement principles
• different speed measurement sensors used in industries
• different applications
  

Session 4

Objectives:

The learner will be able to identify the importance of torque measurement.

Understand:

• What is torque?
• Different torque measurement principles
  
• Pros and cons
• Special features
  

Session 3 (1st July 2010)

Objectives:

The learner will be able to identify the importance of Load cells.

Understand:

• Types of Load cells
• Installation and sensitivity of load cells

Students work:

• Find out industries where load cells can be applied
• Identify the types of load cells for different applications.
• Typical application areas

References:

http://www.sensorland.com/HowPage005.html
http://www.npl.co.uk/reference/faqs/how-many-different-types-of-force-transducer-are-there-%28faq-force%29
http://www.omega.com/prodinfo/loadcells.html

Session 2 (30th June 2010)

Objectives:

The learner will be able to identify the importance of force transducers.

Understand:

• Force measurement methods
• Elastic transducer model

Session 1 (28th June 2010)

Introduction of friends

After this session learner will be able to understand:

1. Introduction to Industrial Instrumentation
2. Role of an Instrumentation engineer: DMIAC
   
3. Need of Industrial Instrumentation
4. Types of Instruments: based on power, based on containment, based on operation
   
5. Types of measurement: direct Vs Indirect
6. Characteristics of Instruments: static and dynamic
   
7. Common process parameters in Industries

Syllabus II - 1

UNIT – I

Measurement of straightness, flatness, roundness and roughness. Electric balance – different
types of load cells – magnets – elastics load cell-strain gauge load cell- different methods of
torque measurement, using strain gauge, relative regular twist-speed measurement – revaluation
counter-capacitive tacho-drag up type tacho D.C and A.C tacho generators – stroboscopic
methods.

UNIT – II

Mechanical type flowmeters: Theory of fixed restriction variable head type flow meters-orifice
plate – venturi tube – flow nozzle – dall tube – installation of head flow meters- piping
arrangement for different fluids – pilot tube. Positive displacement flow meters – constructional
details and theory of operation of mutating disc, reciprocation piston, oval gear and helix type
flow meters-inferential meter turbine flow meter – rotameter – theory and installation – angular
momentum mass flow meter – coriolis mass flow meters – thermal mass flow meter – volume
flow meter plus density measurement – calibration of flow meters – dynamic weighing method.

UNIT – III

Electrical type flow meter: Principle and constructional details of electromagnetic flow meter –
different types of excitation – schemes used – different types of ultrasonic flow metera-laser
Doppler anemometer systems – vortex shedding flow meter – target flow meter – solid flow rate
measurement – guidelines for selection of flow meter.

UNIT – IV

Accelerometers - LVDT, piezo-electric, strain gauge and variable reluctance type accelerometers
– mechanical type vibration instruments – seismic instrument as an accelerometer and vibrometer
– calibration of vibration pick ups – units of density, specific gravity and viscosity used in
industries – Baume scale API scale – pressure head type densitometer – float type densitometer –
ultrasonic densitometer Bridge type gas densitometer.

UNIT – V

Viscosity terms – say bolt viscometer – rotameter type viscometer – industrial consistency meters
– humidity terms – dry and wet bulb psychrometers – hot wire electrode type hygrometer – dew
cell – electrolysis type hygrometer – commercial type dew point meter – moisture terms -
different methods of moisture measurement – moisture measurement in granular materials, solid
penetrable materials like wood, web type material.

Text Books:

1. Ernest O.Doebelin, “Measurement systems Application and Design”, International
Students Edition, IV Edition, McGraw Hill Book Company, 1998.
2. R.K.Jain, “Mechanical and Industrial Measurements”, Khanna Publishers, New Delhi,
1999.

References:

1. D.Patranabis, “Principles of Industrial Instrumentation”, Tata McGraw Hill Publishing
Ltd., New Delhi, 1999.
2. A.K.Sawhney, “A course in Electrical and Electronic Measurement and Instrumentation”,
Dhanpat Rai and Sons, New Delhi, 1999.
3. P.Holman, “Experimental Methods for Engineers”, International Student Edition,
McGraw Hill Book Company, 1971.