The accuracy of measurement varies from 5 mm to 10 mm per km measurement. The nitestar dmi distance measuring instrument survey instrument. Dotz1 pro is a vehicle installed distance measuring instrument dmi offering the most complete set of operating features, while being extremely simple to use. A total station ts or total station theodolite tst is an electronic optical instrument used for surveying and building construction. Electronic distance measurement this text gives an uptodate introduction into. Edm electronic distance meter,applications,advance survey instrument slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Mar 10, 2018 edm electronic distance meter,applications,advance survey instrument slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Designed by the company that invented the first electronic dmi. Pdf calibration of electronic distance meters researchgate. The first edm instrument called geodimeter was developed in sweden in the year 1948. Pdf the establishment of an electromagnetic distance. After preparing experiments, the national board of survey started the electronic distance measurements in 1963 and now uses tellurometermra3 in mainorder measurements. Edm instruments are highly reliable and convenient pieces of surveying equipment and can be used to measure distances of up to 100 kilometers. Pdf calibration of electronic distance measurement.
Let us discuss about these two basic measuring instruments briefly. Instruments based on radio waves are generally called microwave instruments. Apr 17, 2018 edm stands for electronic distance measurement. Perform all of the setup skills for the apparatus 4. We can classify the basic measuring instruments into the following two types. It is excellently suited as a text for undergraduate and graduate students and an invaluable reference for practicing surveyors, geodesists and other scientists. The edm emits a beam of infrared light that is modulated at a controlled rate. Mar 23, 2017 electronic distance measurement edm 1. Electronic distance measuring edm instruments introduction edm are now the prime measuring device for land surveyors and others. It is an electronic transit theodolite integrated with electronic distance measurement edm to measure both vertical and horizontal angles and the slope distance from the instrument to a particular point, and an onboard computer to collect data and perform.
To ascertain this, edme is calibrated on government maintained baselines. Pdf baseline using the straight line configuration approach. Chapter 3 surveying equipment, measurements and errors. One case was found using a noncommercial laser ranging instrument, similar to. Electronic distance measurement edm linkedin slideshare. Methods for measuring distances electric distance measurement edm distances are measured electronically by determining the number of full and partial waves of transmitted electromagnetic energy that are required in traveling the distance between the edm and a prism. Edm is a surveying instrument for measuring distance electronically between two points through electromagnetic waves. Electromagnetic distance measurement edm definition the electronic distance measurement instrument edm is a relatively new development in the field of surveying.
Electronic comparison of the transmitted and received signals allows for computation of the. Edm instrument errors an edm instrument has three inherent systematic errors. Older methodologies that use a set of known information usually distance or target sizes to make the measurement, have been in regular use since the 18th century. Electronic distance measuring instrument is a surveying instrument for measuring distance electronically between two points through. The waves are reflected from another device at the other end back to the transmitter.
Basic working principles of electronic distance meters. Instruments using light or ir waves are classified as electrooptical instruments. Tellurometer first introduced electronic distance measurement to the world early in 1957 with their model mra1, and since then the tellurometer system has been proved internationally over several millions of miles of traverses over all types of terrain and under the most varied and severe climatic conditions. Electronic distance measurement edm is a fundamental feature of modern surveying total stations. The static characteristics of an instrument are, in general, considered for instruments which are used to measure an unvarying process condition. The electronic measurements and instrumentation notes pdf emi pdf notes book starts with the topics covering performance characteristics, ramp type, staircase ramp, wheat stone bridge, block schematic of cro, dual trace, strain gauges, flow measurement, flow measurement, etc. Electronic distance measurement edm is a method of determining the length between two points, using phase changes, that occur as electromagnetic energy waves travels from one end of the line to the other end. Nitestar dmi survey instruments distance measuring instrument. Microwave systems range up to 150 km wavelength 3 cm not limited to line of sight unaffected by visibility light wave.
The reliability and accuracy of electronic distance measurement equipment edme, like any equipment, is critical. The distance measured is always sloping distance from instrument to the object. These instrument rely on propagation of modulated light waves. Figure 42 electromagnetic distance measuring equipment in use.
Electronic distance measuring method edm basic civil. Reflectorless laser distance measurement 16032005 henk key, contributing editor and dr mathias lemmens, editor, gim international aim it at a surface and push the button, and the distance is measured by laser. Pdf electronic distance measurement an introduction. The calibration process identifies any existing errors of the instrument so that adjustments may be made to account for those errors. The calibration process identifies any existing errors of the instrument so. Electronic distance measuring instruments sciencedirect. Wadley at national institute of telecommunications research of south.
A series of measurements on a baseline can also be used to check the performance and. Electronic distance measurement measuring distance. Electronic distance measurement edm instruments, such as laser trackers. Calibration of electronic distance measurement instruments. Forensic science electronic distance measuring edm device. Apr 05, 2017 electronic distance measurement instrument calibration base line policy. Distance measurement by electronic method based on hardwired algorithm relay on propagation, reflection and subsequent reception of electromagnetic wave electronic angle measurement combined the function of. Zenith angles, used as a reference for measuring vertical angles, are defined as 0 directly overhead and 90 at the horizontal plane. They used the phase shift between the outgoing and incoming signals. However, early edms did not work on the speed of light. Electronic distance measurement page 1 electronic distance measurement electronic distance measurement, aka edm, is used in eight field events.
Download electronic distance measurement an introduction ebook free in pdf and epub format. When the satellite navigation receiver is locked onto and tracking orbiting navigation satellites, the highly precise cesiumrubidium clocks. An electronic distance measurer edm can be used to place objects or points in three dimensions in relation to the unit. As long as our distances are shorter than 10 m twoway travel, we can measure with millimeter precision as long as both the wave generator and phase detector electronic can operate to 4 significant figures. These are additive constant, scale factor and cyclic. In the field, make adjustments only when the instrument results are poor or require excessive manipulation. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more. It is an instrument that combines the angle measurements that could be obtained with a traditional theodolite with electronic distance measurements. An electrooptical distance measuring instrument embodying a noncoherent light emitting diode, the light beam of which is directly amplitudemodulated by an oscillator and delivered to a receiver through the agency of means for mixing the modulation phases, a transmitting objective, and a reflector arranged at the remote end of the measuring path.
Using electronic distance measurement instruments in ndt and. Electronic distance measuring edm instrument is a major part of total station. Introduction an electronic distance measurement edm instrument is calibrated on a baseline to determine instrument constants and errors. Electronic measurements and instrumentation pdf notes emi. Aug 16, 2017 electronic distance measurement edm instruments, such as laser trackers, total stations, and handheld laser distance meters, have been used in a limited number of nondestructive testing ndt and structural health monitoring shm applications attempting to measure bridge deflections and vibrations. Electronic distance measurement edm by sabri safee on. Electronic distance measuring instrument is a surveying instrument for measuring distance electronically between two points through electromagnetic waves.
Edm as a component of a total station laser light or infrared. The distance measured by edm is more precise than measured with chain or tape. A combined satellite positioning and electrooptical total station system includes a reference oscillator that provides local oscillator signals for a satellite navigation receiver and a precision frequency source for use by an electronic distance meter. Every distance is measured twice so that at both ends the instrument is used as the master instrument. Abstract electromagnetic distance measurement edm instrument requires a. It is widely used by surveyors, department of transportation, contractors, pavers, construction, and virtually anyone wanting to make distance measurement much faster, accurate, and. Opportunities for the use of electronic distance measurement. It is excellently suited as a text for undergraduate and graduate students and an invaluable reference for practicing surveyors, geodesists and other scientists using edm as a measuring tool. Notes on electronic distance measurement mygeodesy.
All the static performance characteristics are obtained by one form or another of a process called calibration. The total station is the combination of electronic theodolite and electronic distant measurement equipment which can show the angles, elevation and distance. Electronic measuring instruments the instruments used to measure any quantity are known as measuring instruments. If you continue browsing the site, you agree to the use of cookies on this website. Active rangefinding methods include laser, lidar, radar, sonar and ultrasonic rangefinding other devices measure distance using trigonometry are stadiametric, coincidence and stereoscopic rangefinders. Electronic distance measuring edm instruments introduction. Reflectorless laser distance measurement gim international. Electronic distance measurement instrument calibration base line policy. Because of the different structure of these two types of instruments, they will be discussed separately. Improvements to the calibration of electronic distance. As the name suggests, voltmeter is a measuring instrument which measures the voltage across any two points of an electric. Active methods use unilateral transmission and passive reflection.
Various aspects of the propagation of electromagnetic waves through the atmosphere are treated in chapter 5, such as the range of edm instruments, phase and. Such instruments were invented as early as 1950 in south africa by dr. At least every 12 months to a national or state standard primary standard of measurement. Slope distance the slope distance is the shortest distance from the instrument to the target. The national geodetic survey ngs will serve the highprecision needs of the u. Taping distance, with all its associated problems, has been. Electronic distance measuring instrumentation calibration. Older methodologies that use a set of known information usually distance or target sizes to make the measurement. Edm instruments are classified according to the type of carrier wave employed. Electronic distance measurement instrument types, functions, uses. The instrument sends out a beam of light or high frequency microwaves from one end of line to be measured, and directs it towards the far end of the line. When a distance is measured using an edm instrument, some form of electromagnetic wave in our case, infraredirradiation is transmitted from the instrument towards a reflector where part of the transmitted wave is returned to the instrument. Read electronic distance measurement an introduction online, read in mobile or kindle.
Reflectorless laser distance measurement 16032005 henk key, contributing editor and dr mathias lemmens, editor, gim international aim it at a surface and. Us3759616a electrooptical distance measuring instrument. Electronic measurements and instrumentation pdf notes. Electronic distance measurement can be done by instruments like geodimeter, tellurometer or distomat etc. Edm is also used routinely for measuring field event performances and checking the heights of the bar in the high jump and pole vault events at major track and field competitions. Calibration of electronic distance measurement instruments last updated august 2017 1. Chapter 8 electronic distance measurement edm advanced. The main instrument for surveyors on site today is the total station which is an example of electronic distance measurement. Electronic distance measurement an introduction jean m. The second instrument for edm was designed and developed in africa in the. Other devices measure distance using trigonometry are stadiametric, coincidence and stereoscopic rangefinders.
The phase measurement based distance meter tellurometer was developed by t. The nitestar has been created to make distance measuring as simple as possible. Longer range instruments, using coherent laser light, have ranges from 50 feet to 36 miles. Instruments should only be checked under favorable conditions. A total station ts or total station theodolite tst is an electronicoptical instrument used for surveying and building construction. Electronic distance measurement instrument types, functions. Forensic science electronic distance measuring edm. Dotz1 pro distance measuring instrument, vehicle installed. Jun 05, 2017 the total station is the combination of electronic theodolite and electronic distant measurement equipment which can show the angles, elevation and distance.
Geodimeter is geodetic distance meter developed based on a modulated light beam. In most events, a tape measure is used to make the measurements, but the process of. The sensitivity of measurement is therefore the slope of the straight line drawn on fig. If the instruments can measure the basic electrical quantities, such as voltage.
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