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Product catalog summary

Thermocouple Overview:
Thermocouples are categorized by tolerance classes according to IEC 60584-2 standards. Different types such as Fe-Con (J), Cu-Con (T), NiCr-Ni (K), and others have specific temperature ranges and accuracy levels. For instance, Class 1 Fe-Con (J) operates between -40°C and +750°C with an accuracy of ±0.004 * t or ±1.5°C.

Thermocouple Connectors and Calibration:
Connector body colors match the outer sheath colors. Calibration involves measuring thermocouple emf in millivolts at various temperatures, with specific values provided for types T, E, J, K, N, R, S, and B.

Insulation Materials and Applications:
Various insulation materials like PVC, PFA, PTFE, and glassfibre are used, each with specific temperature ranges and properties. For example, PVC is suitable for -10°C to 105°C and is waterproof and flexible.

Platinum Resistance Thermometry:
Resistance vs. temperature and tolerances for platinum resistors are defined by IEC 751 standards. Class A and B tolerances are specified for different temperatures, with Class A offering higher precision.

New Tolerance Classes:
IEC 60751(2008) introduces new tolerance classes for wire wound and film resistors, with specific temperature ranges and tolerance values.

Stem Conduction and Self-Heating:
Stem conduction affects temperature measurement due to heat transfer through the probe. Proper immersion depth is crucial. Self-heating occurs due to current flow through the Pt sensing resistor, affecting temperature readings.

Practical Bridge Circuits:
Diagrams for 2, 3, and 4 wire thermometer configurations are provided, highlighting the importance of wire arrangements for accurate measurements.

Catalog excerpts

THERMOCOUPLE SELECTING SENSOR CABLES: GUIDE TO INSULATION & COVERING Which insulation Material? COLOUR CODES: THERMOCOUPLE CONNECTORS, EXTENSION AND COMPENSATING WIRES AND CABLES INSULATION COLOUR CODES CABLE Extension & Compensating Leads CODE FORMER STANDARD IEC 60584-3(2007) EX NICKEL CHROMIUM/CONSTANTAN (Nickel Chromium/Copper Nickel, Chromel/Constantan, T1/Advance, NiCr/Constantan) _ IRON*/CONSTANTAN (Iron/Copper Nickel, Fe/Konst Iron/Advance, Fe/Constantan I/C) NICKEL CHROMIUM/NICKEL ALUMINIUM* (NC/NA, Chromel/ Alumel, C/A, T1/T2, NiCr/Ni, NiCr/ NiAL) COPPER/CONSTANTAN (Copper/Copper Nickel, Cu/Con, Copper/Advance) EX JX KX NX NC TX Screened or unscreened? With long cable runs, the cable may need to be screened and earthed at one end (at the instrument) to minimise noise pick-up (interference) on the measuring circuit. Alternative types of screened cable construction are available and these include the use of copper or mylar screening. Twisted pair configurations are offered and these can incorporate screening as required. v^ THERMOCOUPLE ACCURACIES Tolerance classes for thermocouples to IEC 60584-2(1982) (Amend 1-1989) BS EN60584-2(1993) Fe-Con (J) Class 1 - 40 +750°C: ±0.004 . t or ±1.5°C Vx COPPER/CONSTANTAN (LOW NICKEL) (Cu/Constantan) Compensating for K (Cu/Constantan) COPPER/COPPER NICKEL Compensating for Platinum 10% or 13% Rhodium/Platinum (Codes S & R respectively) (Copper/Cupronic Cu/CuNi, Copper/No. 11 Alloy) * Magnetic, ( ) Alternative & Trade Name FOR THERMOCOUPLE CONNECTORS body colours are similar to outer sheath colours FOR THERMOCOUPLE CONNECTORS body colours are similar to outer sheath colours CALIBRATION GUIDE Thermocouple Type 100°C t = actual temperature Use the larger of the two deviation values

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PLATINUM RESISTANCE THERMOMETER PRACTICAL BRIDGE CIRCUITS FOR 2, 3 AND 4 WIRE THERMOMETERS The connection between the thermometer assembly and the instrumentation. The cabling introduces electrical resistance which is placed in series with the resistance thermometer. The two resistances are therefore cumulative and could be interpreted as an increased temperature if the lead resistance is not allowed for. The longer and/or the smaller the diameter of the cable, the greater the lead resistance will be and the measurement errors could be appreciable. In the case of a 2 wire connection, little can...

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