are designed for high temperature applications. Cable temperature-sensing element is located in thermowell made of high-alumina (C795) or silicon carbide (CC) ceramic. Ceramic thermowell is partially armoured with steel tube. 01.20 and 01.21 are different in metal armour material (12Cr18Ni10Т and AISI 310S correspondingly). It is possible to replace AISI 310S with 15Cr25T steel. Under operating conditions temperature in transition joint of ceramic and metal thermowell sections should not exceed: 800°С – for 01.20 and 01.20A modifications; 1000°С – for 01.21 modifications.
Thermocouple with silicon carbide thermowell which is noted for increased wear resistance, are recommended for use in presence of abrasive particles in medium being measured, and also for melt zinc temperature measurement. 01.20 and 01.21 thermocouples can be equipped with temperature-indicating insert CTx 01.02-005 with bakelite terminal block. 21.20, 21.21 sensors are recommended if precision temperature measurement is required. Such precision is achieved due to periodic calibration or verification. They are similar to 01.20 and 01.21 modifications, and have the same technical specification.
21.xx thermocouple has an additional channel for control or reference thermocouple installation next to temperature-sensing element inside thermowell. Such construction allows to calibrate temperature-sensing element without thermocouple dismantling according to MI 3091--2007 (see pages 2-16). CETN 01 or CETN 02 are used as reference thermocouples (see section 8).
CTxx 21.XX thermocouple design is proved by patent for invention No. 2299408.
Movable fitting UNKJ 031, UNKJ 041 of movable mounting flange UNKJ 030 are recommended for thermocouple installation. Threaded mounting flange UNKJ 039 is used for 01.23 sensor installation (see section 10 "UNKJ mounting hardware").
Explosion-proof versions 0ExiaIICT6 X or 1ExdIICT6 according to GOST 30852.10-2002 are available (except for 21.20, 21.21). For further details see "Alternative designs & Ordering information" below.
Terminal heads can be equipped with transmitters with 4-20 mА DC output signal and/or digital signal via HART, PROFIBUS-PA, FOUNDATION Fieldbus protocol. It is recommended to use heads of 16, 23, 28 modifications for easy wire connection to transmitters. Terminal head can be equipped with standard or special-purpose cable gland. For further details see "Alternative designs & Ordering information" below.