Tuesday, January 31, 2012

How to make a Piezoelectric Transducer

Hello Friends, in this post i wish to share a video i saw on YouTube today. Watch this video and make your own Piezoelectric Transducer.


If you need any help related to instrumentation and control engineering, use the comments section

Friday, January 20, 2012

Level measurement using Gauge Glass Technique:

A sight glass (also called a gauge glass) is used in the liquid level measurement. It is used for continuous indication of liquid level within a tank or vessel.

Construction and working of Gauge Glass Technique:

A sight glass instrument consists of a graduated tube of toughened glass which is connected to the interior of the tank at the bottom whose water level is to be measured. The image below shows a simple sight glass for an open tank in which the liquid level in the sight glass matches the level of liquid in the tank.

As the level of liquid in the tank rises and falls, the level in the sight glass also rises and falls accordingly. Thus by measuring the level in the sight glass, the level of liquid in the tank is measured.

When it is desired to measure a liquid level with the liquid under pressure or vacuum, the sight glass must be connected to the tank at the top as well as at the bottom, otherwise the pressure difference between the tank and the sight glass would cause false reading. In this case, the glass tube is enclosed in protective housing, and the two valves are provided for isolating the gauge from the tank in case of breakage of the sight glass. The smaller valve at the bottom is provided for blowing out the gauge for cleaning purpose.

Pressure balance is obtained at any points in the fluid which are at equal distances above or below some reference. If the liquids are subjected to the some external pressure and have the same specific gravity, the level will be the same in both vessels.
The image below shows a high pressure sight glass in which measurement is made by reading the position of liquid level on the calibrated scale. This type of sight glass in high pressure tanks is used with appropriate safety precautions. The glass tube must have a small inside diameter and a thick wall.

When the liquid in the tank is under some external pressure, the pressure can be nullified by connecting the sight glass as indicated.

Remote indication

Liquid level in either open tank or closed tank can be measured by sight glass or gauge glass technique. It can be controlled by the operator in the control room by means of monitoring the sight glass fixed at different places of tank with the help of CCTV system. OCD camera is focused at the sight glass or gauge glass and viewed in the control room through a monitor. The image below illustrates the block diagram of the remote indication of level measurement.

Ranges of gauge glass:

The standard practice is not to go in for a glass tube of more than 900mm length. In case the height of the tank is more than 900mm, two or more sight glass level gau ges are provided at different levels. This type of gauge is made to withstand pressures of 150 kg/cm^2 of steam pressures at 250’C or 450kg/cm^2.

Advantages of gauge glass:

  1. Direct reading is possible.
  2. Special designs are available for use upto 3000’c and 650 kg/cm^2.
  3. Glassless designs are available in numerous materials for corrosion resistance.

Disadvantages of gauge glass:

  1. The main disadvantage is that, it is read where the tank is located which is not always convenient.
  2. Since sight glasses are located outside the tanks, the liquid in the sight glass may freeze in clod weather even though the liquid inside the tank does not, and thus, it may cause error in the reading.
  3. Heavy, viscous liquids or liquids containing material which fall out of solution and clog the tube cannot be measured satisfactory by sight glass.
  4. Overlapping gauges needed for long level spans.
  5. Accuracy and readability depends on cleanliness of glass and fluid.

Friday, January 13, 2012

Construction and Working of Float level switch

The most known and simple level switch consists of a float which is mounted on a moveable arm and magnetically coupled to a micro switch (outside the process). Also versions exist with a spherical float, which contains a small magnet and move upwards a tube. In the tube one or more reed relays are placed. The reed relays will switch as the (magnetic) float passes by. The image below shows a simple float type mechanism.



Advantages of Float level switch

  1. Relatively simple.
  2. It is suitable for various products
  3. Low cost.


Disadvantages of Float level switch

  1. Requires a certain mounting
  2. No reproduction switch point
  3. There is a malfunction in case of build-up.
  4. It is not fail-safe.


Wednesday, January 11, 2012

List of Instruments and Methods used in Level Measurements:

In this post I will list out all the Instruments and Methods used in Level Measurements.


  1. Level measurement using gauge glass technique.
  2. Float type level indication
  3. Float level switch
  4. Float / rope method
  5. Float operated spring loaded level switch
  6. Magnetic float device
  7. Level measurement using displacer and torque tube
  8. Air purge system/bubbler system
  9. Thermal level sensors
  10. Low level conductivity switch
  11. Thermal level sensor with heater and probes
  12. Capsule type thermal level sensor
  13. Expansion type thermal level sensor
  14. Hydrostatic pressure method
  15. Differential pressure method
  16. Level measurement using resistance tapes
  17. Capacitance level detection
  18. Radiometric level detection
  19. Ultrasonic sensors
  20. Microwave time of flight method
  21. Non-conducting optical level sensor
  22. Optical sludge level detector
  23. Light refraction type level switch
  24. Level detection using fiber optics
  25. Radar level transmitters
  26. Laser level devices
  27. Level switches

Wednesday, January 4, 2012

Virtual Instrumentation Based projects with Abstract

I have collected a list of projects with abstract based on virtual Instrumentation  for my reader, select the topic that you find it interesting and do a great project.

Measure And Test System Of Belt Driving Based On Labview

Abstract—For the sake of overcoming the shortcoming of the traditional belt driving system such as manual work date reading and large human errors, The belt-driven test system based on LabVIEW is developed, which is composed of mechanism, data collection device, DC PWM system, electromagnetic brake, photoelectricity velocity sensor and pressure sensor. Based on the virtual instrument technology, a humanized human-computer interface is designed. In the system, the test of various parameters including rotate speed of belt pulley, output power, Elastic slide rate ?? and drive efficiency ?? are automatically realized. Experiments explain that the system owns high realtime performance and dependability, and that it has a good application prospect.

Data Acquisition System Based On Labview For Abs Dynamic Simulation Test Stand

Abstract - Anti-Lock Braking System (ABS) has become a standard configuration for vehicles. We created a virtual environment to approximate the external conditions by using ABS dynamic simulation test stand to test the performance of ABS. Measurement and analysis of the test stand are two important issues for ensuring the high quality of ABS. In this paper, an automatic measurement and examination platform based on powerful software LabVIEW is designed and implemented. LabVIEW is easy for monitoring and data acquisition. Parameters of the test stand are recorded and analyzed simultaneously by applying LabVIEW. In order to make the testers immerse in the movement environment, we created an animation interface which can supply real-time driving scene according to the running state of the test stand. The complex animation of driving scene is carried out with programming.

Pc-Based System For Level Transducer Interfacing

Abstract— Many applications rely on accurate readings from level transducers for a correct behaviour of complex systems. Large chemical and food industry plants employ large numbers of such devices which have to generate a correct behaviour and provide an accesible reading of the data. This paper presents an application for level measurement using appropiate signal conditioning and data aquisition hardware. We start by presenting the physical principles of level transducers and their classification. Signal conditioning, as an essential factor to obtaining correct readings is also highly regarded. The advantages of PC-based systems are then observed (compatibility, low-cost) along with the additional benefits brought by developing the software application in a graphical programming environment such as LabVIEW. We describe in depth the hardware system involved and the functionality of the written software. We add considerations regarding the performance of the overall system including hardware and software features. One interesting fact is that we have run the data aquistion application in an virtualized environment so we are able to make a performance-wise comparison among the virtualized and non-virtualized scenarios. The main output of the paper is the a software application for the measurement of the liquid level in a knownvolume tank, which can be easily deployed across multiple computers due to its stand-alone characteristic. It is an appropiate tool for teaching and research projects and can easily be extended for the more stringent requirements of industrial tasks, such as reliabilty and compatibility with existing industrial systems.

A Multisensor Intelligent Device For Real-Time Multiphase Flow Metering In Oil Fields

Abstract—In this paper, a new multiphase flow metering device for real-time measurement of oil, gas, and water flow rates is presented. It is composed of several electrical and acoustic sensors whose signals are digitalized and processed by a multilayer neural network. This latest uses the physical models of multiphase fluids to reduce the complexity of the parameter space while improving its accuracy. Furthermore, to overcome the uncertainties of the electrical sensors in the range of 40%–60% and above 90% water- cut (i.e., ranges where most of the multiphase flow meter fail), two rings of high- and low-frequency ultrasonic sensors are used for low and high gas fractions, respectively. The results of experiments that have been conducted in an in-house laboratory-scale multiphase flow loop show that real-time classification for up to 90% gas fraction can be achieved with less than 10% relative error.

A Laboratory Testbed For Embedded Fuzzy Control

This paper presents a novel scheme called “Laboratory Testbed for Embedded Fuzzy Control of a Real Time Nonlinear System.” The idea is based upon the fact that project-based learning motivates students to learn actively and to use their engineering skills acquired in their previous years of study. It also fosters initiative and focuses students attention on authentic realworld problems. At the same time, it enhances their learning. Students gain hands-on experience and improve their skills in product development, self-directed learning, teamwork, and project management. There has been a tremendous rise in the popularity of intelligent control techniques like fuzzy logic for use in industrial control applications in recent times. These techniques, which were primarily conceived for nonlinear control applications, are best implemented using embedded controllers, which can use their capabilities to the maximum. While courses in electrical and computer engineering cover several areas like digital and analog integrated circuits, microprocessors and control Systems, and process control, few of these integrate all these areas with focus on the application of intelligent techniques in real-time systems. Also, there is a growing need in industry for engineers who can perform software design and system integration for various applications in embedded control. This paper aims at developing such a practical task as one of the major projects in the eighth semester of the program offered by the Instrumentation and Control Engineering (ICE) Department of Netaji Subhas Institute of Technology (NSIT), Delhi University, India, to design a real-time embedded controller implementing an intelligent control technique, fuzzy logic, for control applications. These applications might, for example, be level control, flow control, or pressure control. The paper discusses an example of a real-time pressure control system for which a microcontroller- based fuzzy proportional-integral-derivative (PID) controller has been simulated and implemented with satisfactory results.


Application Of Prognostic And Health Management Technology On Aircraft Fuel System

Prognostic and Health Management (PHM), which could provide the ability of fault detection (FD), fault isolation (FI) and estimation of remaining useful life (RUL), has been applied to detect and diagnose device faults and assess its health status, with aiming to enhance device reliability, safety, and reduce its maintenance costs. In this paper, taking an aircraft fuel System as an example, with virtual instrument technology and computer simulation technology, an integrated approach of signal processing method and model-based method is introduced to build the virtual simulation software of aircraft fuel PHM system for overcoming the difficulty in obtaining the failures information from the real fuel system. During the process of constructing the aircraft fuel PHM system, the first step is to analyze the fuel system failure modes and status parameters that can identify the failure modes. The main failure modes are determined as joints looseness, pipe broken, nozzle clogging, and fuel tank leakage. The status parameters are fuel pressure and fuel flow. Then, the status parameter model is constructed to imitate the behavior of sensor which detecting fuel system status. On this basis, utilizing the signal processing module provided by Labview software, the outputs from the virtual sensors, which collect the failure data, are processed to realize the simulation of failure detection and failure diagnosis. All the result shows that the virtual simulation software well accomplishes the task of the aircraft fuel system failure detection and diagnosis.

Implementation Of A Fully Automated Greenhouse Using Scada Tool Like Labview

The paper discusses the automation of a free-standing greenhouse using Supervisory Control & Data Acquisition (SCADA) system. The end product is expected to give the farmer or enduser a kiosk type approach. Entire greenhouse operation will be governed and monitored through this kiosk. This approach is fairly novel considering the unified system design

Labview Based Simulation System For The Output Characteristics Of Pv Cells And The Influence Of Internal Resistance On It

By using LabVIEW as software, a model of solar cells based on its output characteristic is built. The output characteristics of silicon solar cells and the maximum power point tracking system are simulated under different solar radiations. The influence of the internal resistance to the maximum power point and the fill factor of silicon solar cells are also simulated. The simulation results verify the nonlinear output characteristic of silicon solar cell and the system is proved to be very effective in determining the most appropriate load to stabilize the maximum power point of the cell. It is also proved by the results that the internal resistance is a key factor to the maximum power point and the fill factor of solar cells.

IRIS Recognition

Sorry Abstract not available

A Labview Based Virtual Instrument For On-Line Inductios Motor Parameters Identification

Sorry Abstract not available

PACED BREATHING CONTROLLER USING LABVIEW

Paced breathing devices are designed and used for exactly that... paced breathing. Often when a researcher is conducting an experiment that requires analyzing biological signals, the number of variables are reduced by keeping all the subject’s rate of breaths per minute (BPM) the same. Presently there exists both software and hardware that serves the purpose of this task. This project has combined both of these to build a new apparatus using the latest technology. Instead of a hardware device which is difficult to manipulate once constructed, the software package LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is used to construct this device. LabVlEW is a icon driven package which parallels actual electrical components. If the situation arises in which changes need to be made, they can be performed relatively easily assuming there is some knowledge of the software at hand. The convenience of this arises because manipulations can be made without the use of a soldering iron or any other tool with the exception of a mouse.

Labview-Based Universal Battery Monitoring And Management System

In this paper the main principles and the general structure of battery monitoring and management systems (BMS) are explained. Furthermore, a newly developed, highly accurate and inexpensive data acquisition system for BMS is presented. The modular measuring system consists of two different types of monitoring units, a battery block-voltage monitoring unit and a battery current- and temperature monitoring unit. Following the discussion of the measuring hardware, a LabView realization of a universal BMS software is described in detail. Due to the flexible design of the LabView BMS, the system is able to perform control and surveillance activities for any kind of battery application and battery technology (e.g. Pb, VRLA, NiCd, NiMH etc.). The BMS was originally designed for VRLR batteries in uninterruptible power supply systems (UPS), but was also tested in electric vehicles (VW CityStromer, BMW).

Development Of A Virtual Instrument For Data Acquisition And Analysis Of The Phonocardiogram

A medical virtual instrument has been developed to acquire and analyze the phonocardiogram (PCG), the heart sound and murmur signal. This instrument consists of a Pentium 200 computer running Windows95, equipped with LabVIEW software and a plug-in data acquisition board, and a two-channel custom designed bio-signal preamplifier. The bio-signal preamplifier allows the data acquisition board to acquire both the PCG and the electrocardiogram (ECG). LabVIEW software modules have been developed to create virtual instrument’s front panels for the following functions: to manage patient information and data files, to capture and display current ECG and heart sound signals while saving or analyzing previous acquired signals, to perform the spectral and time-frequency analysis of the heart sounds and murmurs, and to review the previous recordings. This instrument can be used to display the PCG and to analyze the individual heart sound and murmur for the detection of heart valve diseases. It can also be used to analyze the carotid bruit for the diagnosis of carotid artery stenosis. This study demonstrated that a LabVIEW-based medical virtual instrument provides a low-cost, reliable, and flexible solution for data acquisition and analysis of the PCG and carotid bruit.

Open-Loop Motor Speed Control With Labview

Sorry Abstract not available

Towards An Internet-Based Virtual-Wire Environment With Virtual Instrumentation

An Internet-based virtual-wire application that uses virtual instrumentation to achieve a continuous control of a closed loop control system is presented. The system acquires data from remote signal sources and publishes them via the Internet in the real-time, while enabling the remote user to send control signals from the web-browser to the server application for the control of a PID based control system. The system involves the development of the server application using LabVIEW graphical programming language and the client application, which is a Java Applet embedded to a HTML format. Problems and limitations of achieving stable continuous control of the system by the remotely licated computers are discussed. It was found that continuous control of a real time system via the Internet is possible, but a sustained virtual wire application with the current limitations of Internet technology is impossible.

Closed-Loop Position Control System Using Labview

An Internet-based virtual-wire application that uses virtual instrumentation to achieve a continuous control of a closed loop control system is presented. The system acquires data from remote signal sources and publishes them via the Internet in the real-time, while enabling the remote user to send control signals from the web-browser to the server application for the control of a PID based control system. The system involves the development of the server application using LabVIEW graphical programming language and the client application, which is a Java Applet embedded to a HTML format. Problems and limitations of achieving stable continuous control of the system by the remotely licated computers are discussed. It was found that continuous control of a real time system via the Internet is possible, but a sustained virtual wire application with the current limitations of Internet technology is impossible

A Labview Based Data Acquisition System For Vibration Monitoring And Analysis

Sorry Abstract not available

Effective Simulation Of Signals For Testing Ecg Analyzer

In this paper the solution of the specialized measuring system for electrocardiography (ECG) signal recording and introductory recognition is presented. The project aims at designing the complete PC-based Virtual Instrument as a “testing platform” for acquisition, processing, presenting, and distributing ECG data. A new design involving the latest technique in signal simulation was developed to create a controllable model of the electrocardiography signal. Then it was implemented for testing of the developed QRS detection algorithm, based on the time-frequency analysis method. The processing stage involving discrete wavelet transform was used to detect QRS complexes in the ECG signal. By using the controlled signal model and the real ones, the algorithm was shown to be advantageous in reducing ventilation artifacts and motion noise, resulting in good accuracy.

Remote Calibration Using Mobile, Multiagent Technology

Instrument calibration, though unavoidable, is extensively time and resource consuming. It often involves a distinct layer of data management and security. Since many of the available digital instruments are provided with communication interfaces, one can build a remote calibration system from the actual hardware and a computing unit with Internet connection capabilities. This paper, after showing a simple client–server architecture, discusses how the use of mobile, multiagent techniques is expected to solve most of the security issues, working as well and effectively as a traditional, agent-free client–server architecture.

Monday, January 2, 2012

Fuzzy logic control

Introduction to Fuzzy logic control

In fuzzy logic control the experience of human process operator, is incorporated in design of the controller. This logic controller provides a means of converting a linguistic control strategy based on operates knowledge into an automatic control strategy, linguistic variables are quantities like high, medium, low, etc., fuzzy logic is multivalued logic which enhances man machine interaction. Fuzzy logic is implemented using fuzzy sets.

A set is a well defined collection of objects. A crisp set is one which identities whether the object is present in that collection or not.

The function A(x) is such that


That is the object x will either belong to set or not.

Fuzzy set is one that allows partial membership of object in that set here the degree to which a variable is member of a given set is indicated.

Let X be a set and x is an element of X. then fuzzy set A is given by

A = {A(x)/x} ; x E X

A(x) given degree of membership and has a range of 0 to 1. it indicates that the degree of membership of an element x in a fuzzy set A ranges from 0 to 1 where 0 indicates null membership. 1 indicates full membership, and intermediate values represent partial membership.

Advantages of Fuzzy logic control:


  1. Relates input to output in linguistics terms; easily understood.
  2. Cheaper because they are easier to design.
  3. Increased robustness.
  4. Can achieve less overshoot & oscillation.
  5. Can achieve steady state in a shorter time interval.
  6. Simplify knowledge acquisition & representation.


Disadvantages of fuzzy logic control


  1. Hard to develop a model from a fuzzy system.
  2. Require more fine tuning and simulation before operational.