From uncertaintyto stability
21.21 тип ТППТ, ТПРТ
15
15
21
23
24
26
28
21.21 тип ТППТ, ТПРТ
Thermocouples are designed for temperature measurement in liquid and gaseous non-corrosive media, and also corrosive media that do not damage protective cover material. Thermocouple design allows sensing element calibration without thermocouple dismantling.
21.21 modification thermocouple is manufactured using five-channel straw made of aluminium-oxide ceramics (C799). Control thermocouple can be mounted in central bore 4 mm diameter. Four peripheral bores allows to product thermocouple with one or two sensing elements. Five-channel straw is mounted inside ceramic thermowell.
22.21 thermocouple has two inner ceramic thermowells, that are positioned in parallel. One of inner thermowell is designed for control or reference thermocouple.
TCS, TCR (TCB) 21.21 and 22.21 thermocouples are equipped with outer thermowell made of aluminium-oxide ceramic; inner thermowell is made of gas-tight aluminium-oxide ceramic.
Space between outer and inner thermowell is packed with powder Al2O3.
Outer ceramic thermowell is partially reinforced with a heat-resistant steel pipe. Temperature in transition zone between ceramic and metal thermowell parts should not exceed 1000°C under operating conditions.
At customer's request thermocouple 21.21 can be equipped with single thermowell made of gas-tight aluminium-oxide ceramics 15 mm diameter. In this case metal armouring should be made of Fe-Cr-45%Ni alloy.
Thermowell ceramic part length (K) should be explicitly specified at the time of order.
TCS, TCR (TCB) 21.21 and 22.21 work point structure is shown in the picture.
22.21 thermocouple design is covered by utility model patent No. 94700.
Tolerance class
1 - 2 for TCS and TCR
2 - 3 for TCS and TCR
material of thermowell working part
C799 – aluminium-oxide ceramics, Al2O3 content is not less than 99.5%;
Note: to prevent ceramic thermowell destruction due to high temperature gradient when thermowell is immersed in working medium, thermocouple heating rate should not exceed 150°С/min.
Hot junction
one or two, ungrounded
Thermocouple wire diameter
Designation |
Positive wire diameter |
Negative wire diameter |
|
А |
0.5 |
0.5 |
|
В |
0.4 |
0.5 |
|
С |
0.4 |
0.4 |
Thermal inertia index does not exceed
110 s — if space between inner and outer thermowell is packed with Al2O3 powder;
300 s — no powder Al2O3
nominal (rated) pressure:
0.4 MPa
|
TC type |
operating temperature range, °С |
material of thermowell working part |
|
TCS, TCR |
0 to 1300 |
C799 |
|
TCB |
600 to 1600 |
Insertion length L: 500, 630, 800, 1000, 1250, 1600, 2000 mm.
Thermocouple type |
Design |
Wire |
Tolerance |
Hot junction |
Thermo- |
Diameter |
Insertion |
Ceramic |
||
|
modification |
typical |
min |
max |
|||||||
|
TCS |
21.21 |
020, |
А, В, С |
1, 2 2, 3 (TCB) |
U, U2 |
C799 |
15 |
500 |
2000 |
400 to 1250 |
|
24 |
||||||||||
|
22.21 |
022 |
24 |
||||||||
* – see Appendix for version description.
** – typical version: TCS, TCR - 2 tolerance class; TCB - 3 tolerance class.
TCS, TCR (TCB) 21.21-022 - (А, В, С)Х - U(2) - C799 - D - L / C
TCS, TCR (TCB) 22.21-022 - (А, В, С)Х - U(2) - C799 - 24 - L / C
TCS 21.21-020 - A1 - U - C799 - 15 - 600 / 400 –type S calibration thermocouple TCS, modification 21.21-020 with possibility to calibrate without dismantling, 0.5+/0.5– mm thermocouple wire diameter (A), tolerance class 1, one ungrounded junction (U), aluminium-oxide ceramic thermowell (C799) diameter 15 mm, total insertion length (L) 600 mm, thermowell ceramic part length (C) 400 mm.
TCB 21.21-022 - A2 - U2 - C799 - 24 - 800 / 600 –type B calibration thermocouple TCB, modification 21.21-022 with possibility to calibrate without dismantling, 0.5+/0.5– mm thermocouple wire diameter (A), tolerance class 2, two ungrounded junctions (U2), aluminium-oxide ceramic thermowell (C799) diameter 24 mm, total insertion length (L) 800 mm, thermowell ceramic part length (C) 600 mm.
TCS 22.21-022 - A1 - U2 - C799 - 24 - 1000 / 400 –type S calibration thermocouple TCS, modification 21.21-022 with possibility to calibrate without dismantling, 0.5+/0.5– mm thermocouple wire diameter (A), tolerance class 1, two ungrounded junctions (U2), aluminium-oxide ceramic thermowell (C799) diameter 24 mm, total insertion length (L) 1000 mm, thermowell ceramic part length (C) 400 mm.