Variable Diameter Thermocouple

Variable diameter thermocouple is a structural improvement product developed on the basis of conventional assembly thermocouple positive, which adopts the method of welding a small protective tube in the measuring end part of the product (generally 50mm), and reduces the diameter of the measuring end part to $8~12m, so as to overcome the shortcomings of slow thermal response time of conventional assembled products.

Products Description

The reducer thermocouple is composed of four parts: reducer protective sleeve, thermocouple core (can be assembled core or armored core), installation fixture, and wiring device.

Technical characteristics

Variable diameter thermocouple has all the characteristics of conventional assembly products, in line with the three industry standards for assembling thermocouples, it solves the slow thermal response time of conventional assembly products and the lack of installation strength of conventional armored products to a certain extent, and has a wide range of uses in the field of medium and low temperatures. In particular, in recent years, the use of armored thermocouples as the core of prefabricated products can also be used as the core of variable diameter thermocouples, so that variable diameter thermocouples have been more widely used.

Threaded thermocouple probes Conductor Combinations And Characteristics

Type	Thermoelement	Temperature range ℃	Function Features
Type	Thermoelement	Temperature range ℃	Advantages	Disadvantages
K	NiCr10-NiSi3	-40~1200	With good thermoelectric EMF linearity, good stability and good oxidation resistance. It's the most widely used thermocouple.	Not suitable for reducing atmosphere.
N	NiCrSi-NiSiMg	-40~1250	With all the advantages as K type thermocouple, more stability in high temperature environment.	Not suitable for reducing atmosphere.
E	NiCr-Constantan	-40~900	Highest thermoelectric output among all thermocouples, the sensitivity is high.	Not suitable for reducing atmosphere, low thermal conductivity.
J	Fe- Constantan	-40~750	Can be used in reducing atmosphere, thermoelectric is higher than K type thermocouple.	Iron rusts easily, thermoelectric drift easily.
T	Copper- Constantan	-40~350	Can be used in reducing atmosphere, with good thermoelectric EMF linear and stability.	Using temperature is not high, the positive copper is easy to oxidize.

Threaded thermocouple probes Limit Of Error

Thermoelement	Type	Limits Of Error(±℃)/Effective Temperature Range(℃)
Thermoelement	Type	I class	II class	III class
NiCr10-NiSi3	K	1.5 or 0.4%t/-40~1000	2.5 or 0.75%t/-40~1200	2.5 or 1.5%t/-40~200
NiCrSi-NiSiMg	N	1.5 or 0.4%t/-40~1000	2.5 or 0.75%t/-40~1200	2.5 or 1.5%t/-40~200
NiCr-Constantan	E	1.5 or 0.4%t/-40~800	2.5 or 0.75%t/-40~900	2.5 or 1.5%t/-40~200
Fe- Constantan	J	1.5 or 0.4%t/-40~750	2.5 or 0.75%t/-40~750	--
Copper- Constantan	T	0.5 or 0.4%t/-40~350	1.0 or 0.75%t/-40~350	1.0 or 1.5%t/-200~40