Mineral Insulated Resistance Thermometers (RTD)

Transcription

1 Mineral Insulated Resistance Thermometers (RTD) Electronic Temperature Measurement Data sheet : MIRTD/2012 Contents Page RTD Element Type 2 Conductors & Number of Wires 2 Probe Diameter 3 Length Types 3 Terminal & Process Glands 4 Cold End Termination Types 5 Plug / Socket Arrangements 7 FLP (Oil Seal) / Seal Temperature Rating 7 Tail Wire / Extension Cable 8 Overall tail / Extension Cable Length 9 RTD Order Codes 10 y High Accuracy and Stability y Good Linearity y No Compensating Cable y No Cold Junction Compensation Mineral Insulated Probe Overview The outer sheath is made from malleable metal in a wide range of diameters, containing single or multiple solid conductors. The probes are easily formed or bent, it can accommodate virtually any configuration. The outer sheath protects the thermocouple or RTD from oxidation and hostile environments, and the mineral insulation provides excellent high temperature dielectric strength. The construction of the cable guarantees a long conductor life and thus the function of the conductor because the sheath and the insulating powder protect the conductors (cores) against environmental conditions such as corrosion. The cables are pliable, The compact construction with densely packed mineral powder and the robust metal sheath ensure the position of the conductors in the compound and thus the function of the cable even when exposed to mechanical stresses such as bending, Since the insulation is attained exclusively from powders on a mineral base the cables can be exposed to considerably higher temperatures than cables with synthetic sheaths.the high density of the mineral powder effects rapid transmission of heat between conductor and sheath: This factor makes the cable highly suitable for temperature measurement and control techniques. General Description A Resistance Thermometer is a temperature sensor constructed from resistance wire wound into an element. It is used to measure temperature by means of a change in the electrical resistance with a rise or fall in temperature. The most popular wire used in Resistance Thermometers is platinum. Platinum Resistance Sensors offer the highest standard of accuracy and stability of any temperature sensor. They also exhibit good linear response, covering a temperature range from -200ºC to +650ºC. The majority of the resistance thermometers produced use platinum wound ceramic detectors manufactured to the PT100 standard (BS EN 60751:1996), but they can be manufactured to other standards. The sensors can be 2-wire, 3-wire or 4-wire, depending on the requirements of the application and instrumentation. Most commercial and industrial application are 3-wire, with 4-wire being used for high accuracy and laboratory applications. Accuracy is dependent on the class of the sensor specified; Class A, Class B, 1/3 1/5 1/10 tolerance are available Excellence the World can Measure TM

2 Element Types (table 1) Code Element Type Tolerance Class BS EN 60751:2008 IEC 60751:2008 Mineral Insulated Resistance Thermometers 2 Temperature Range R1 R2 R3 R4 PT100 (Wire Wound) C PT100 (Wire Wound) C PT100 (Wire Wound) C PT100 (Wire Wound) C Class B (Standard) ± ( x T) -196 to 600 C Class A ± ( x T) -100 to 450 C Class AA (1/3 DIN) ± ( x T) -50 to 250 C 1/5 DIN ± ( x T) / 5 Not Covered by BS EN 60751: to 150 C Code Element Type Tolerance Class Tolerance Deviation Temperature Range R5 R6 PT1000 (Thin Film) C PT1000 (Thin Film) C Class B (Standard) ± ( x T) -196 to 600 C Class A ± ( x T) -100 to 450 C Code Element Type Tolerance Class Tolerance Deviation Temperature Range R7 PT130 (Wire Wound) C Class B (Standard) N/A -196 to 600 C Conductor & Number or Wires (table 2) Code Number of Wires A 2 wire B 3 wire C 4 wire D 2 x 2 wire E 2 x 3 wire F 2 x 4 wire

3 Sheath Material & Conductors (table 3) Mineral Insulated Resistance Thermometers 3 RTDs are available in 2, 3 or 4 wire configurations with a range of sheath materials and conductor materials. Standard sheath materials include 316 Stainless Steel, 321 Stainless Steel and Inconel 600. For high temperature applications, a nickel sheath is preferred. Conductors are usually either copper or nickel. Code Material Max. Operating Temperature Conductor Diameter (mm) A SS 316 Ni Wire 600 ºC B SS 321 Ni Wire 600 ºC C Inconel 600 Ni Wire (Non-stock) 600 ºC SIMPLEX SIMPLEX SIMPLEX DUPLEX DUPLEX SIMPLEX SIMPLEX DUPLEX SIMPLEX SIMPLEX Probe Diameter (table 4) Code Diameter B mm C mm D mm Length Type (table 5) Code Probe Length Image P Probe Length Probe Length R Route Length Route Length L Length Under Base Plate Length Under Base Plate H Length Under Head Length Under Head

4 Terminal & Process Glands (table 6) Mineral Insulated Resistance Thermometers 4 Terminal Gland Process Gland Code Fitting Type Size EExde Material Diameter to Suit mm 01A 1/8 02A BSP 1/4 Stainless Steel 04A 1/2 01E 1/8 02E BSPT 1/4 Stainless Steel 04E 1/2 01C 1/8 02C NPT 1/4 Stainless Steel 04C 1/2 58G M16 58I Metric Stainless Steel 59G M20 59I XXX No Glands

5 Cold End Termination Types Springloaded Terminal Blocks Available as a high grade ATEX approved moulded Ryton block, or as general purpose ceramic version. Both terminal blocks can accommodate sheath sizes from mm to mm diameter, and can be fitted with up to six terminals. The Ryton block is suitable for temperatures up to 260ºC, and when used in conjunction with an appropriate Thermocouple Instruments connection head, provides a complete assembly approved to ATEX EExde IIC. Both terminal blocks are fitted with 2 x M4 screws mounted on 33 mm centres. Transmitter Baseplate RTDs can be manufactured with DIN mounting plates to suit temperature transmitters. We can offer a full range of ATEX approved transmitters, from fixed range devices to HART smart devices. Moulded Plugs The 3PS plug is a standard round pin moulded plug suitable for mm, mm and mm diameter RTDs. Maximum ambient temperature is 270ºC. A duplex version is also available. A miniature version is also available, with flat pins. Both standard and miniature connections can be supplied in socket end versions. Mineral Insulated Resistance Thermometers 5 An alternative range of high temperature plug and socket combinations is available with ceramic bodies. Standard Seals A wide variety of standard and custom designed seals can be manufactured to suit specific applications. The C Pot is a stainless steel crimped-on epoxy resin seal, suitable for mm, mm and mm diameter RTDs. Maximum ambient temperature is 105ºC when fitted with PVC tail wires and 180ºC when fitted with PTFE tail wires and high temperature epoxy. A high temperature glazed seal version is available, with ceramic beaded tail wires, suitable for temperatures up to 350ºC. The PS1 Pot is a standard crimped-on stainless steel seal for mm diameter RTDs. Threaded Seals The A Pot is an M8 threaded epoxy resin seal for mm and mm RTDs. The B Pot is an M10 threaded epoxy resin seal for mm, mm and mm, or 8.0 mm RTDs. Locknuts can be supplied. Maximum ambient temperature is 105ºC when fitted with PVC tail wires and 180ºC when fitted with PTFE tail wires and high temperature epoxy. Base Plates with Tails (table 7) Code Type Material Temperature Rating Conductor Diameter Image A B Plain Base Plate Spring Loaded base Plate 304 Stainless Steel Standard Tail Wire for RTD is PTFE DIN Blocks (table 8) Code Type Material Temp. Rating Conductor Diameter Image C D E PBT (Standard) Ryton Block (Used for ATEX certified Products ONLY) Ceramic Block (High Temp, Poor Electrical properties when damp) PBT (Plastic) 210ºC RYTON (Plastic) 260ºC Ceramic Higher Temperature Applications SIMPLEX DUPLEX SIMPLEX DUPLEX SIMPLEX DUPLEX

6 Seals (table 9) Code Type Pot Material Conductor Diameter Image G H I J A Pot M8 Thread A Pot M8 Thread with M8 Lock Nut B Pot M10 Thread B Pot M10 Thread with M10 Lock Nut Stainless Steel Stainless Steel K C Pot Plain Stainless Steel L PS1 30mm Stainless Steel 2 x 2 & 2 x 3 2 x 2 & 2 x 3 2 x 2 & 2 x 3 (2 x 4 6mm only) 2 x 2 & 2 x 3 M PS1 50mm Stainless Steel Mineral Insulated Resistance Thermometers 6

7 Connectors - Plugs & Sockets We can supply a wide range of connectors for use with thermocouples and resistance thermometers. The items described on this page represent a small sample of the different types available. Please contact sales office for further information. Plugs and In-Line Sockets Plugs and in-line sockets are available for use with all types of thermocouples and resistance thermometers. Thermocouple plugs may be standard (P4) or miniature (P3) sizes. Plugs and sockets to suit duplex elements can also be supplied. A wide range of cable glands and clamps, suitable for most wire and cables, can be specified. Mineral Insulated Resistance Thermometers 7 Panel Mounted Sockets Sockets for panel mounting are available to suit standard and miniature thermocouple plugs. Round or rectangular versions are available. DIN Terminal Blocks Terminal blocks are available in either Ryton or ceramic construction. The Ryton block is ATEX approved to EEx e II for increased safety applications. Maximum operating temperature is 240ºC. The ceramic terminal block conforms to DIN 43735, and has a maximum operating temperature of 350ºC. Blocks are available with 2,4,6 or 8 (ceramic only) terminal posts. Plugs or Sockets directly mounted to MI cable are available with a Probe in a 3 Wire RTD configuration. Plugs or Sockets connected via Cable are available in 1.5,, & Probes in a 3 Wire RTD configuration. Plug / Socket Directly Mounted (table 10) Code Type Temperature rating of Plug / Socket Type K Thermocouple N P3 Plug 220ºC Continuous O P4 Plug 220ºC Continuous P P3 Socket 220ºC Continuous Q P4 Socket 220ºC Continuous Plug / Socket Connected via Cable (table 11) Code Type Temperature rating of Plug / Socket Type K Thermocouple R C Pot with P3 Plug & Cable 220ºC Continuous S C Pot with P4 Plug & Cable 220ºC Continuous T C Pot with P3 Socket & Cable 220ºC Continuous U C Pot with P4 Socket & Cable 220ºC Continuous FLP (Oil Seal) / Seal Temperature Rating Ferrule / Collar (table 12) Code Type S Standard Ferrule F FLP Collar / Oil Seal Collar Note: Only used with Base plate or DIN Block Seal Temperature Rating (table 13) Code Type Temperature Rating S LOW (Standard) Up to 80ºC F HIGH Up to 200ºC Note: Only used with Seals

8 Tail Wire / Extension Cable All tail wires are 7 strands of 0.2mm core wire (7/0.2) Mineral Insulated Resistance Thermometers 8 Standard Tail Wire (table 14) Code Conductor Insulation Sheath Insulation Outer Sheath B PTFE N/A N/A 200ºC Temp. Rating Conductor RTD Configration Image 2 x Extension Cable Wire (table 15) Code Conductor Insulation Sheath Insulation Outer Sheath C PTFE PTFE N/A 200 C D Glass Glass N/A ABOVE 200 C F PTFE PTFE SS 200 C G PTFE PTFE SS 200 C H Glass Glass SS ABOVE 200 C I PTFE SS PTFE 200 C Temp. Rating Conductor RTD Configuration Image 2 x 2 x 2 x 2 x 2 x 2 x

9 Overall Tail / Extension Cable Length (table 16) Mineral Insulated Resistance Thermometers 9 Overall Length Strip Length Probe with Tail Wires Overall Cable Length Flying Tails Strip Length Probe with Extension Cable Cable Length Probe with Extension Cable & Plug / Socket

10 Ordering Code - Mineral Insulated Resistance Thermometers Mineral Insulated Resistance Thermometers 10 RTD Element Type (table 1) PT100 Class B (Standard) PT100 Class A PT100 Class AA (1/3 DIN) PT100 1/5 DIN PT1000 Class B (Standard) PT1000 Class A PT130 Class B R1 R2 R3 R4 R5 R6 R7 Conductors & Numbers of Wires (table 2) Sheath Material (table 3) Probe Diameter (table 4) Length Type (table 5) Length Enter length in mm Terminal Gland (table 6) Process Gland (table 6) Cold End Termination Type (tables 7 thru 11) Temperature Rating (tables 12 & 13) Tail Wire / Extension Cable (tables 14 & 15) Extension Length (table 16) Enter length in mm Flying Tail Length (table 16) Enter length in mm TM ISO9001:2008 British Rototherm Company Limited Kenfig Industrial Estate, Margam, Port Talbot SA13 2PW United Kingdom Excellence the World can Measure TM T: +44 (0) F: +44 (0) E: sales@rototherm.co.uk W: In keeping with British Rototherm s policy for continual product development and improvement, we reserve the right to amend specifications without notice Rototherm Group. All rights reserved. Company registered in Wales : Registered office as above.