Technical Information RTD Insert for Temperature …

1 Technical InformationTI 268T/02/en60019747 RTD Insert for Temperature Sensoromniset- TPR 100 Mineral insulated insertThermoresistance sensing elementPCP ( mA), HART or PROFIBUS-PA electronicsThe TPR 100 is a thermoresistance insertdesigned to be the universal measure-ment probe of RTD sensors, and it is oftenutilized as a replaceable measuring ele-ment in in compliance with thestandards DIN EN 60751 and DIN 43735,it consists of a mineral insulated cableand a Pt 100 sensing element. It can beconnected to the conversion electronicsby means of flying leads or in alternativewith a terminal TPR 100, thanks to the numerousavailable versions, satisfies the most partof industrial and laboratory the structure s options, the usercan choose several types of Pt 100 for thedifferent applications, different kinds ofstem and certification use of wire wound or thin film sensingelement, allows two different operatingmeasurement ranges, respectively C and C.

2 Features and benefits Mineral insulated cable sheathed in SS 316 3 or 6 mm diameter stem or tapered Customized immersion length Different kinds of Pt 100 and classes of tolerance (DIN EN 60751): wire wound type, class A or 1/3 DIN B, single or double thin film type, class A or 1/3 DIN B 4 wires connection for single Pt 100, 3 wires connection for double Pt 100 Electronics included in the ordering structure: PCP ( mA, also with enhanced accuracy), HART and PROFIBUS-PA 2-wire transmitters Factory calibration certificate ATEX 1 GD EEx ia certificationomniset TPR 1002 Endress+ HauserAreas of applicationTPR 100 is an universal RTD Insert ; it is the fundamental part of a thermometer assembly.

3 It can be used in various kinds of application: from the food industry to the chemistry one, thanksto its characteristics and enclosed and system designMeasuring principleIn RTD (Resistance Temperature Detector) inserts the sensing element consists of an electricalresistance with value of 100 at 0 C (called Pt 100, in compliance with standard DIN EN 60751),which increases at higher temperatures according to a coefficient characteristic of the resistormaterial (Platinum). In industrial thermometers compliant with DIN EN 60751 standard, the valueof that coefficient is = *10-3 C-1, calculated between 0 and 100 architectureThe TPR 100 is made up of a MgO cablesheathed in SS 316 with 6 or 3 mm diam-eter; the sensing element (Pt 100) is positionedclose to the tip of the probe.

4 A tapered tip is alsoavailable and it s obtained from a 6 mm sheathreduced in the last 50 mm to a 3 mm outer diam-eter. At the opposite extremity the Insert has awasher, which is crimped on the stem. The func-tion of the washer is to stop the Insert at the rightinsertion length, when assembled with a connec-tion head. The version having the flying leads as terminals,is indicated if the Insert has to be connecteddirectly to a head transmitter, otherwise there isthe alternative with the terminal block, which ispermanently fixed to the a TPR 100 is mounted into a sensor withthermowell, it is fixed by means of two spring-loaded screws, which allow the tip of the Insert togo properly in contact with the bottom of the ther-mowell, ensuring in this way a better thermal con-tact.

5 The springs are useful also to compensatethe thermal electrical structure of the instrument alwayscomplies with DIN EN 60751 standard sensing element is supplied in the two ver-sions thin film (TF) or wire wound (WW), the lasthaving an extended range of measurement 1:Overall dimensions of TPR 100 MaterialStem in SS 316 , terminal block in ceramics. WeightFrom to kg for standard TPR 100 Endress+ Hauser3 ElectronicsThe required type of output signal can be obtained by choosing the right head-mounted transmit-ter. Endress + Hauser supplies state-of-the-art transmitters (iTEMP series) built in 2-wire technologyand with mA, HART or PROFIBUS-PA output signal.

6 All the transmitters are easily pro-grammable with a personal computer through the ReadWin 2000 public domain software ( mA and HART transmitters) or Commuwin II software (for PROFIBUS-PA transmitters).HART transmitters can be programmed also with the DXR 275 (Universal HART Communica-tor) hand-held operating PCP ( mA) model (TMT 180) with enhanced accuracy is available. For detailed Information regarding transmitters, please refer to the relevant documentation (seeTI codes at the end of this document).PerformanceOperating conditionsMaximum process pressureStem2 MPa (20 bar) at 20 CProcess temperatureSame of measurement flow velocityWhen in direct contact with process fluid, the highest flow velocity tolerated by the Insert stemdiminishes with increasing lengths exposed to the stream of and vibration resistanceAccording to DIN EN 60751 g peak / 10 500 HzAccuracyProbe maximum error (Pt 100 type TF) cl.

7 A 3 = + | C3 = + C cl. 1/3 DIN B3 = + | C3 = + / C3 = + CProbe maximum error (Pt 100 type WW) = + C cl. 1/3 DIN B3 = + | C3s = + / C(ItI = absolute value of Temperature in C)Grafic_g_gd_05_it_14_AGrafic_g_gd_05_e n_01omniset TPR 1004 Endress+ HauserTransmitter maximum errorSee relevant documentation (codes at the end of this document).The "4 wires" configuration, supplied as standard for single Pt 100, ensures no additional errors incase of long connecting cables (without head-mounted transmitter). Generally speaking, there isa higher guarantee of accuracy in the "4-wires" "2 wires" connection, employed in the Atex certified version of the Insert , could cause an addi-tional error due to the resistance of the (copper) conductors in the mineral insulated cable, whichadds to the Pt 100 value.

8 The incidence of this source of inaccuracy increases with longer inser-tion range wire wound Pt C thin film Pt CResponse timeTest in water at m/s (according to DIN EN 60751; 23 to 33 C step changes):InsulationInsulation resistance between terminals and probe sheathmore than 100 M at 25 C(according to DIN EN 60751, test voltage 250 V)more than 10 M at 300 CSelf heatingNegligible when E+H iTEMP transmitters are 100 is normally mounted into thermometer assemblies where a thermoresistance is installation inside an assembly is very easy.

9 It s enough to Insert the TPR 100 into a housingand to screw down in the appropriate holes the two spring-loaded screws, in order to fix thewasher to the internal base of the housing (see fig. 2).The insertion length (IL) of an Insert has a considerable role, since the tip of the probe must be incontact with the bottom of the host thermowell. In this way the thermal transfer from the wall of thethermowell to the sensing element is assured, and the response time will be surely reduced. More-over it should be a good rule to leave less empty space as possible between Insert and thermo-well, in order to enhance the heat transmission; therefore the right stem diameter must be chosenwith regard to the well bore 100 can be also used directly for the Temperature measurement, avoiding the employmentof a protection well; for this solution a process connection (usually an adjustable one like a com-pression fitting) will fix the Insert to the pipe or vessel, and define the right immersion length (seefig.)

10 2). Thanks to the construction with mineral insulated cable, the Insert can be easily bended up to aradius of 3 times the stem diameter (see fig. 3, not for tapered tip version). In case of vibrations, the thin film (TF) sensing element may offer some advantages, but thebehaviour depends on intensity, direction and dominant frequency in the vibrational the contrary the wire wound (WW) Pt 100, besides a wider range of measurement and accu-racy, assures a better long term detailed Information regarding adjustable process connections, as well as on ATEX-certifiedcomponents (transmitter, Insert ), please refer to the relevant documentation (see TI codes at theend of this document).