Temperature Sensing www.tempco.com | (800) 323-6859 | email: [email protected] 14-117 ANSI Type (J) Standard; Special Tolerance (3) Type J is composed of a positive leg (JP) which is iron and a nega- tive leg (JN) which is approximately 45% nickel, 55% copper. When protected by the compacted mineral insulation and appropri- ate outer sheath, Type J is usable from 32°F to 1500°F. Type J is not susceptible to short range ordering in the 700 to 1000°F tem- perature range (+2°F to +4°F drift), which occurs with ANSI Type E and K. This low-cost, stable thermocouple calibration is primarily used with 94% minimum purity MgO insulation and a stainless steel sheath. ANSI Type (K) Standard; Special Tolerance (4) Type K is composed of a positive leg (KP) which is approximately 90% nickel, 10% chromium and a negative leg (KN) which is approximately 95% nickel, 2% aluminum, 2% manganese and 1% silicon. When protected by the compacted mineral insulation and appropriate outer sheath, Type K is usable from 32°F to 2300°F and is one of Tempco’s most popular calibration types. If the appli- cation temperature is between 600°F and 1100°F, we recommend using Type J or Type N because of short range ordering that can cause drift of +2°F to +4°F in a few hours’ time. Type K is relative- ly stable to radiation transmutation and is used in nuclear environ- ments. For applications below 32°F, special alloy selections are usually required. ANSI Type (E) Standard; Special Tolerance (5) Type E is composed of a positive leg (EP) which is approximately 90% nickel, 10% chromium and a negative leg (EN) which is approximately 45% nickel, 55% copper. When protected by the compacted mineral insulation and appropriate outer sheath, Type E is usable from 32°F to 1650°F. This thermocouple has the highest EMF output per degree of all ANSI recognized thermocouples. If the application temperature is between 600°F and 1100°F, we rec- ommend using Type J or Type N because of short range ordering that can cause drift of +2°F to +4°F in a few hours’ time. For appli- cations below 32°F, special alloy selections may be required. ANSI Type (T) Standard; Special Tolerance (6) Type T is composed of a positive leg (TP) which is pure copper and a negative leg (TN) which is approximately 45% nickel, 55% cop- per. When protected by the compacted mineral insulation and appropriate outer sheath, Type T is usable from 32°F to 662°F. Type T is very stable and is used in a wide variety of cryogenic and low temperature applications. For applications below 32°F special alloy selections may be required. ANSI Type (N) Standard; Special Tolerance (7) Type N is composed of a positive leg (Nicrosil) which is approxi- mately 14% chromium, 1.4% silicon, 84.6% nickel and a negative leg (Nisil) which is approximately 4.4% silicon, 95.6% nickel. When protected by compacted mineral insulation and appropriate outer sheath, Type N is usable from 32°F to 2300°F. Type N was designed to overcome several problems inherent in Type K thermo- couples. Short range ordering (+2°F to +4°F drift) in the 600°F to 1100°F temperature range is greatly reduced, and the drift rate at high temperatures is considerably less. Type N has also been found to be more stable than Type K in nuclear environments. ANSI Type (R) Standard Tolerance Type R is composed of a positive leg (RP), which is 87% platinum, 13% rhodium and a negative leg (RN), which is 100% platinum. When protected by compacted mineral insulation and appropriate outer sheath, Type R is usable from 32°F to 2700°F. Type R is available as standard limits only, ITS90. ANSI Type (S) Standard Tolerance Type S is composed of a positive leg (SP), which is 90% platinum, 10% rhodium and a negative leg (SN), which is 100% platinum. When protected by compacted mineral insulation and appropriate outer sheath, Type S is usable from 32°F to 2700°F. Type S has a lower EMF output than Type R and is available as standard limits only, ITS90. ANSI Type (B) Standard Tolerance Type B is composed of a positive leg (BP) which is approximately 70% platinum, 30% rhodium and a negative leg (BN) which is approximately 94% platinum, 6% rhodium. When protected by compacted mineral insulation and appropriate outer sheath, Type B is usable from 1600°F to 3100°F. Type B is available as standard limits only, IPTS 1968 scale. Tungsten—5% Re/Tungsten, 26% Re (C) This calibration has not been given a letter designation by ANSI. When this calibration is protected by mineral insulation and appro- priate outer sheath, it is usable from 32°F to 4200°F. Calibration is used most often with Beryllium Oxide insulation and either molyb- denum or tantalum sheath. These combinations can only be used in an inert or vacuum environment. Miscellaneous (O) Consult Tempco with your requirements. Mineral Insulated Cable Calibration NOTE: Letters in parentheses following the sheath material are used with the Ordering Worksheet on page 14-119.
