Pdf contamination of platinum resistance thermometers by. From these data, a mean value of the ratio of thermometer resistance to standardresistor re. Resistance thermometers are made from a length platinum that is either wrapped around a ceramic or glass core or has been deposited on a ceramic base. Carvill, in mechanical engineers data handbook, 1993. A platinum resistance thermometer prt was selected for this application. A platinum resistance thermometer, most commonly referred to as a prt, is an electronic device used within a circuit. The four wire resistance thermometer configuration even further increases the accuracy and reliability of the resistance being measured. Resistance thermometers utilise a high precision sensing resistor, usually. The basis of the international practical temperature scale of 1968 from 259. The metals most used are platinum and nickel, for which the resistance increases with temperature in a linear manner. The market was surveyed for a prt probe that would meet these accuracy and. Common rtd sensing elements constructed of platinum, copper or nickel have a repeatable resistance versus temperature relationship r vs t and operating temperature range.
Resistance thermometer for measuring the surface temperature of tanks and pipes. Pdf contamination of platinum resistance thermometers by silver. When terminating the resistor with extension wires, a decision must be made as to whether a 2, 3 or 4 wire arrangement is required for measurement purposes. Flush mounted silver temperature sensor, thermally isolated. Resistance thermometers rtd rpi portable resistance thermometer for generical and laboratories measurements, available for surface, immersion and penetration measurements.
This document outlines the recurrent concepts and technologies that apply to all resistance thermometers produced by wika. Platinum resistance thermometer article about platinum. Wika part of your business solutions for pressure, temperature, force and level measurement, flow measurement, calibration and sf 6 gas solutions from wika are an integral component of our customers business processes this is why we consider ourselves to be not just suppliers of measurement components but rather more a competent partner that offers comprehensive solutions in close co. Resistance thermometers according to din monitoring.
Jul 05, 2017 a platinum resistance thermometer has resistances of 200. Calibration of industrial platinum resistance thermometers up. These thermometers operate on the principle that electrical resistance changes in pure metal elements, relative to temperature. In top diagram a standard two terminal rtd is used with another pair of wires to form an additional loop that cancels out the lead resistance. Platinum resistance thermometer elements scientific instrument. A platinum resistance thermometer has a resistance r 0 50.
Platinum resistance thermometers prt characteristics. Wika your partner for pressure, temperature and level. Platinum resistance thermometer prt selection guide. The probe have a glass filled plastic handle and the extension cable is spiralized. Resistance thermometers are suited for di rect temperature measurement of gaseous and liquid media.
Resistance thermometer definition of resistance thermometer. The applications for the measuring inserts are not limited. For best accuracy with modern equipment choose characterization. In preparation for the its90 many national laboratories designed platinum resistance thermometers that would work to the gold point of 1064c. Fluke calibration secondary standard prts fill the gap between affordable, but temperaturelimited secondary reference prts and more expensive, highly accurate sprts. Platinum resistance thermometer information peak sensors. The r vs t relationship is defined as the amount of resistance change of the sensor per degree of temperature change.
Both wirewound and thinfilm sensorbased thermometers were investigated. Platinum resistance thermometer instrument britannica. The connection between resistance thermometer and measuring instrument is mostly of the 2wire type the sum and compensation of line resistance become part of the measurement. It is used both for precision measurements of the highest accuracy and for routine industrial work. Operating limits and tolerances of platinum resistance. Resistance thermometers are sensors that allow determining temperature by measuring the electrical resistance of the sensor, assuming that it is in thermal equilibrium with the medium to. Operating limits and tolerances of platinum resistance thermometers per en 60751. Resistance thermometers operating instructions wika usa. Its operations are carried out in such a way as to fully exploit the fast response of the thermistor and the high accuracy of the platinum thermometer. How to calibrate an rtd or platinum resistance thermometer. The traditional sensing element of a resistance thermometer consists of a coil of small diameter wire wound to a precise resistance value.
Here you can find the operating instructions of our resistance thermometers for download. Find out information about platinum resistance thermometer. Thermometer, resistance a temperaturemeasurement device whose operation is based on. The companys temperature laboratory uses a range of reference platinum resistance thermometers, noble metal thermocouples, stirred liquid baths, specially designed isothermal calibration furnaces and black body sources to provide a comprehensive facility for cost effective thermometer calibration or temperature probe calibration over the range 80 deg c to 1,200 deg c. Sensor technology the electrical resistance of a resistance thermometer s sensor changes with the temperature. The dominant standard adopted internationally is the pt100 which has a resistance value of 100. Standard specification for industrial platinum resistance. R t resistance at temperature t ohm r 0 resistance at temperature 0 o c ohm t temperature o c a 3. The use of platinum is quickly becoming the standard in resistive thermal devices because of its ability to remain accurate in.
Evaluation of some hightemperature platinum resistance. It is only used when high accuracy is not required, as the resistance of the connecting wires is added to that of the sensor, leading to errors of measurement. Resistance thermometer an overview sciencedirect topics. Resistance thermometers operating instructions wika. A wide variety of platinum resistance thermometer options are available to you, such as usage, theory. Contamination of platinum resistance thermometers by silver article pdf available in metrologia 305. Platinum resistance thermometer calibration procedures are similar whether the method selected is characterization or tolerance testing. This wide temperature range requires several thermometer types, which are included as part of the 162 series shown in table 1. Platinum resistance thermometer seite 1 11 graff gmbh, bonner str. Resistance thermometer minitherm with threaded connection. Theseleadanchoragesaresecuredtothecoreby twosmallplatinumclampsc,fig. Platinum resistance thermometer definition of platinum. For equipment that does not allow characterization, tolerance testing may be your only choice and this is a common situation in industry today.
Recent modifications in the construction of platinum. Resistance thermometers according to din model twl exia screwin resistance thermometer form 3g with neckpipe, protection exia, tapered thermowell g 1 male according to din 43772 for faster response time, pmax 30 bar immersion resistance thermometer form 1, protection exia, thermowell according to din 43772 with adjustable flange, pmax 10 bar. Platinum resistance thermometers prts fluke calibration prts provide a wide operating range and high accuracy required for precision temperature measurement in the laboratory, factory, or field. Specifications tw3039 screwin resistance thermometers.
Resistance thermometers, also called resistance temperature detectors rtds, are sensors. Standard platinum resistance thermometer calibrations from the ar tp to the ag fp pdf. Resistance thermometers utilise a high precision sensing resistor, usually platinum, the resistance value of which increases with temperature. Wika part of your business solutions for pressure, temperature, force and level measurement, flow measurement, calibration and sf 6 gas solutions from wika are an integral component of our customers business processes. A platinum resistance thermometer has resistances of 200. If you want a very stable thermometer and prefer a probe with optional. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. The simplest resistance thermometer configuration uses two wires. Highprecision measuring instruments for temperature and density. After completion, repeat the process for the additional uuts. Industrial platinum resistance thermometer tables r0.
Resistance thermometers may be called rtds resistance temperature detectors, prts platinum resistance thermometers, or sprts standard platinum resistance thermometers. Temperatures on celsius and fahrenheit thermometers related to temperature ranges. Platinum resistance thermometers within a limited range several metals and alloys have an approximately linear resistivity alteration depending on temperature. Thermometers failed to perform to the expected stabilities and so the its90 reduced the upper temperature of contact thermometry to the silver point 961. Resistance thermometers are based on the fact that the electrical resistance of a metal wire varies with temperature. Other articles where platinum resistance thermometer is discussed. What links here related changes upload file special pages permanent link page information wikidata item cite this page. This applies equally to balanced bridge and fixed bridge system.
Pt100 or pt measuring resistors are normally used for industrial applications. Such thermometers consist of a metal wire or strip wound onto a rigid quartz, porcelain, or mica form enclosed in a. Resistance thermometers made of pure metals, especially platinum, with a temperature coefficient of resistance. The relative change in resistance temperature coefficient. According to iec 751 the nominal value is defined as 100. A platinum resistance thermometer prt is a thermometer constructed from a high purity platinum element wirewound coil or thin film placed in a tube of metal or glass and sealed with an inert atmosphere andor mineral insulator. Resistance thermometers use a sensor, whose resistance depends upon temperature and material used a particular change in resistance serves as a measuring unit of temperature. Resistance thermometers operating instructions wika singapore.
Wika your partner for pressure, temperature and level measurement. Resistance thermometers data sheets wika singapore. Industrial grade platinum resistance thermometers were calibrated in the temperature range from 200 c to 700 c. Platinum resistance thermometer thermocouple thermistor sensor platinumwire wound or flat film resistor thermoelement, two dissimilar metalsalloys ceramic metal oxides accuracy typical values 0. This configuration allows use of 100 meters of cable. All resistance thermometers manufactured by peak sensors comply to international standards as defined in iec 60751. About 78% of these are temperature instruments, 0% are testing equipment, and 0% are pressure transmitters.
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