People in ancient times used the different parts of their bodies to size things up. Classification of measuring instruments electrical. Download 10 measuring instruments and their uses pdf at the end of the article. With a need to make quality products which meet design specified tolerances, a large number of firms, research and development centers, and school and college laboratories use measuring instruments that have high accuracy and precision. Electronics and electrical measuring instruments and their. Angle measuring instruments i universal bevel protractor 1 it is an angular measuring instrument capable of measuring angles to within 5 min 2 the name universal refers to the capacity of the instrument to be adaptable to a great variety of work con gurations and angular interrelations.
Classification, absolute and secondary instruments, indicating instruments, control, balancing and damping, constructional details, characteristics, errors in measurement, ammeters, voltmeters. In the past, a common time measuring instrument was the sundial. The instruments duty is to measure the given specimen according to the given dimensions. The indications are given by a pointer moving over a calibrated scale. Upon issuance of the oiml certificate, the applicant becomes the owner of the oiml certificate and associated type evaluation report and test reports. The common quantities used in industries and which are considered for measurement include fluid. The corrective measures employed to eliminate or to reduce these undesirable effects are. Measuring instruments that are present in any branch of industry, are subject to different levels of supervision, like in case of laboratories. These types of measuring instruments having deflection proportional to the square of the current or voltage under measurement can be used for dc as well as ac measurements. With direct measurements, measuring instruments such as vernier calipers, micrometers, and coordinate measuring machines are used to measure the dimensions of the target directly. The magnitude of one of the quantity is unknown, and it is compared with the predefined value. Those instruments that measure and indicates the magnitude of the electricity.
Today, the usual measuring instruments for time are clocks and watches. The disadvantage is they are unable to respond rapidly to measurement of dynamic and transient conditions. Section 3 of the national measurement regulations 1999 nmr defines a legal measuring instrument that is, one used for a legal purpose other than trade as one used in determining a physical quantity. These errors are due to the external condition of the measuring devices. There are two main types of the measuring instruments. Instrument, validity, reliability research rundowns. A measuring instrument is a device for measuring a physical quantity. We can classify the basic measuring instruments into the following two types.
Different types of errors in electrical measuring instruments no electrical measuring instrument can be made with perfect accuracy but it is important to find out what accuracy actually is and how different types of errors have entered into the measurement actual reading. Craig generalized configurations and functional descriptions of measuring instruments it is desirable to describe both the operation and performance static and dynamic of measuring instruments and associated equipment in a generalized way without recourse to specific physical hardware. Electrical instruments measure the various electrical quantities like electrical power factor, power, voltage and. Of all the different types of validity that exist, construct validity is seen as the most important form. They are very reliable for static and stable conditions. Modern surveying instruments and their uses in civil. For further classification details, i have explained each type of electrical measuring instruments in another article. Ringed instruments are handed with the box locks closed.
The process of measuring and controlling various quantities in industries by utilizing various industrial instruments is called as industrial instrumentation. In order to reduce the gross errors in measurement, different correction factors must be applied and in the extreme condition. The devise that is used for measurement of certain physical quantity is called as measuring instrument. Classification of measuring instruments the instrument used for measuring the physical and electrical quantities is known as the measuring instrument. Understanding about industrial instrumentation in real. Types of angular measuring instruments pdf by mohammed shafi march 29, 2020 april 1, 2020 angular measuring instruments are the devices that are used to measure the angle of the given specimens. Here we are interested in electrical measuring instruments so we will discuss about them in detail. Types of applications of measurement instrumentation. Center for effective school practices rutgers university. Measurement types of instruments rsmichael constructing instruments preceding steps work well for questionnaires, attitude measures, personality scales. The measurement type can be divided as, direct measurement method, optical measurement method and. Certain applications of measuring instruments may be characterized as having essentially a monitoring function, e. Stop watches are also used to measure time in some sports.
Likert type scales and other instruments that do not have. The analogue instruments indicate the magnitude of the quantity in the form of the pointer movement. These types of errors include loading effect and misuse of the instruments. Curved instruments are passed with the curve in the direction of intended use.
These instruments converts the energy of the measured quantity directly into energy that actuates the instrument and the value of the unknown quantity is measured or displayed or recorded directly. May 05, 2017 linear measurement in engineering survey, the linear horizontal distance is to be measured to complete a survey. These errors may occur due to hysteresis or friction. Established standard objects and events are used as units, and the process of measurement gives a number. Each measuring instrument serves a specific purpose for the person who is using it. Like its name, it works like an ammeter, voltmeter, and ohmmeter to measure current, voltage, and resistance, respectively. Direct and indirect measurements measurement system. The ammeter, voltmeter, wattmeter are the examples of the electrical measuring instrument. Instrument is the general term that researchers use for a measurement device survey, test, questionnaire, etc. Electrical measuring instruments definitions, types. The sample was 87 baccalaureate student nurses in the third and final semesters. The purpose of this paper is to analyze the existing methods. Linear measuring instruments are used for the measure the straight surfaces of substances.
The electrical instrument is used for measuring electrical quantities likes current, voltage, power, etc. Explore pce instruments wide selection of monitoring, analysis, testing and measuring instruments used to measure various parameters in the physical, electrical and chemical spectra. The planning, the strategy and the practical aspects of a noise survey are discussed in chapter 7. Linear measurement types, instruments and common errors. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of realworld objects and events. The dynamic characteristics of a measuring instrument describe its behavior between the time a measured quantity changes value and. Control of processes and operations an instrument can serve as a component of a control system.
There are two methods for performing dimensional measurements. Electrical measuring instruments electrical measuring instruments published by iskra mis, d. As the name suggests, voltmeter is a measuring instrument which measures the voltage across any two points of an electric. Depending on research type, methods of data collection include. The selection of measuring instruments is a complex task, which depend on the size, the character and the value of measured magnitude. Supervision relates to those instruments that are in continuous use, and such which are out of operation or such those ordered by a customer for future operation. Many types of measuring systems can be used for the measurement of sound depending on. Classification of electrical instruments electrical tutorials. Functional descriptions of measuring instruments functional elements of an instrument active and passive transducers analog and digital modes of operation null and deflection methods inputoutput configuration of instruments and measurement systems methods of correction for interfering and modifying inputs. Primitive peoples needed measuring to perform tasks such as building dwellings, fashioning clothing and interchanging food. Validity and reliability haradhan kumar mohajan premier university, chittagong, bangladesh email. To help distinguish between instrument and instrumentation, consider that the instrument is the device and instrumentation is the course of action the process of developing, testing, and using the device.
Measurement instruments for assessing the performance of. One has to learn reading such instruments since there are certain markings on the scale. I universal bevel protractor 1 it is an angular measuring instrument capable of measuring angles to within 5 min 2 the name universal refers to the capacity of the instrument to be adaptable to a great variety of. Without these instruments, it is not possible to measure the dimensions of the specimen.
Classification of measuring instruments electrical measurements. Taper measuring instruments are used for the measuring slope type of surfaces on the components. Most discussions of instrument reliability are concerned with the relative agreement between two equalstatus operationalizations of a particular construct, but some are devoted exclusively to absolute agreement. Measuring instruments measuring instruments are used to measure physical quantities.
Linear measurement can be achieved by various instruments. In that time, body parts such as arms and feet were often used as measuring instruments. Classification of measuring instruments circuit globe. Such types of errors mainly occur due to the effect of temperature, pressure, humidity, dust, vibration or because of the magnetic or electrostatic field. Measurement instruments for assessing the performance of professional learning communities tools cynthia l. Try to step back in time and imagine a world without measurement tools. Mar 15, 2020 basically there are three types of measuring instruments and they are electrical measuring instruments mechanical measuring instruments. Linear measuring instruments are divided into 4 types which are based on the utility.
There is an old saying that instruments are better than the people who use them. Data collection instruments questionnaire and interview. Let us discuss about these two basic measuring instruments briefly. Classification of measuring instruments instrumentation. For controlling any quantity, primarily that particular quantity has to be measured. Types of electrical measuring instruments absolute and. The term measurement means the comparison between the two quantities of the same unit. But before proceeding further, it good to refresh the definitions and terms used in measurements, instruments. Multimeters are a popular type of electrical measuring instrument. Scientists, engineers and other humans use a vast range of instruments to perform their measurements. Some what different procedures are needed for cognitive domain instruments. With a need to make quality products which meet design specified tolerances, a large number of firms, research and development centers, and school and college laboratories use measuring instruments that. Measurement types of instruments 14 rsmichael cognitive domain instruments achievement instruments.
Types of precision measuring instruments used in industry. The measurement of this linear horizontal distance between two points on the earth surface is known as linear measurement. Sep 11, 2018 measuring instruments plays a vital role in the engineering workshop. Ordinary ammeters, voltmeters, wattmeters, frequency meters. For highly accurate measurement of time an atomic clock is used. The dial resistors are 20 the slide wire of the potentiometer is circular and has 10 turns and a resistance of 10. Whats more, you can preset test conditions of up to 20 different types of safety standards, such as those for information technology equipment, home appliances, medical devices, and measuring instruments, in the memory on the main units panel. An example of a measuring instrument used for trade purposes is a public weighbridge.
A study of errors is a first step in finding ways to reduce them. Jul 20, 2014 electrical measuring instruments definitions, types. These instruments are most widely used in engineering practice because they are simple and inexpensive. The digital measuring instruments indicate the values of the quantity in digital format that is in. B dynamic characteristics of instruments the static characteristics of measuring instruments are concerned only with the steadystate reading that the instrument settles down to, such as accuracy of the reading. Oct, 2017 basics of measuring instruments and types s. Modern surveying instruments provides faster and more precise surveying than conventional instruments. Choose from more than 800 different kinds of desktop and handheld measuring and test equipment in stock and ready to ship to your location. A good electrical measuring instrument used in an unintelligent way may give erroneous results.
Finally, note the class or classes of measurement instruments most relevant to measuring the indicators of interest column 3. There are a few measuring instruments that are more commonly seen than others. Questionnaire a questionnaire is a data collection instrument consistant of a series of questions and other. Digital instruments have some advantages over analog meters, in that they have high accuracy and high speed of operation. Direct and indirect measurements measurement system basics. Their types and uses are discussed in this article. A general rule that null type instruments are more accurate than deflection types analogue and digital instruments analogue. Types and use of precision measuring instruments bright hub. Design, manufacturing and testing of gauges of all kinds. Instrumental errors occur due to wrong construction of the measuring instruments. Too often, the types of errors caused in measurements are due to the fault of the operator than that of the instrument. Electrical measuring instruments types accuracy precision. This chapter describes the noise measuring instruments most widely used in the practice of occupational hygiene.
A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Questionnaire a questionnaire is a data collection instrument consistant of a series of questions and other prompts for the purpose of gathering. Data about energy meters can be found in separate brochure. In conventional surveying, chain and tape are used for making linear measurements while compass and ordinary theodolites are used for making angular measurements. Click on the hyperlink of a speciic instrument in appendix ds table of contents to retrieve the informa tion about the instrument, determine whether it meets your needs, and ind out how to obtain a copy.
Mar 29, 2020 types of angular measuring instruments pdf by mohammed shafi march 29, 2020 april 1, 2020 angular measuring instruments are the devices that are used to measure the angle of the given specimens. Measurement is an important part of science, construction, art, design and a wide array of other professional fields. Handling instruments instruments are placed firmly into the surgeons palm in such a manner that it is ready of immediate use. Current measuring transformers 66 special demands 67 general explanations 68 dimensional drawings 72 conection diagrams 87 instruments conformity to standards 105 note. Apr 14, 2020 for further classification details, i have explained each type of electrical measuring instruments in another article. Measuring instruments used for any other legal purpose. In this post we will discuss about classification of electrical instruments. Moving iron, dynamometer type moving coil, hotwire, electrostatic instruments.
An inch was the width of a mans thumb, a hand was literally meant five fingers across, a span was the length of an outstretched arm, and the yard in the 12th century was the distance from king henry is nose to the thumb of his. This tool compiles 49 instruments for measuring key performance indicators of professional learning communities for teachers. Construct validity forms the basis for any other type of validity and from a scientific point of view is seen as the whole of validity mislevy, 2007. Examples which may be cited for this misuse of the instrument. Signals that vary in discrete steps and that take a finite number of different values in a given range are digital signals and the corresponding instruments are of digital type. Different types of errors in electrical measuring instruments.