This Is A Feature Of Most Measuring Instruments Which Allows For The Fact That The Thermocouple Input Termination Is At Varying Temperature Other Than Stable At 0°C.

To Eliminate The Possibility Of Earth Loops Resulting In Measurement Errors And To Reduce The Danger Of Voltage Pick Up From Electrical Heaters.

Film Uses Platinum Deposition On A Substrate; Wire Wound Uses A Helically Wound Pt Wire In Ceramic. Wire-Wound Type Provides Greater Accuracy And Stability But Is Vulnerable To Shock; Film Type Is Resistant To Shock And Has Quicker Thermal Response.

A Fabricated Thermo pocket Uses A Welded Construction To Allow For Relatively Long Immersion Lengths; A Thermowell Is Machined From Solid Material.

To Protect The Sensor From The Process Medium And To Facilitate Its Replacement If Necessary.

One With Two Separate Sensors In A Single Housing.

They Have Been Developed Over Many Years To Suit Different Applications World-Wide.

Generally, Type N Is More Stable And Usually Lasts Longer Than Type K; N Is A Better Choice For High-Temperature Work Depending On The Choice Of Sheath Material.

An Industry Standard Platinum RTD With A Value Of 100 Ohms @0°C To IEC751; This Is Used In The Vast Majority Of RTD Assemblies In Most Countries.

To Published, Internationally Specified Tolerances As Standard, Typically ± 2.5°C For Popular Thermocouples, ±0.5°C For RTD. Higher Accuracy Sensors Can Be Supplied To Order, E.G. ±0.5°C For Type T Thermocouple, ±0.2°C For RTD. All Of These Values Are Temperature-Dependent. A Close Tolerance, 4-Wire RTD Will Give Best Absolute Accuracy And Stability.

An MI Is Flexible, A Fabricated Sheath Is Rigid.

Because All 3 Are Encountered. Two-Wire Should Be Avoided, Three-Wire Is Widely Used And Four-Wire Gives Optimum Accuracy. Your Instrument Will Be Configured For 2,3 Or 4 Wire.