To understand how to use armored thermocouples for temperature measurement, you need to know the thermal response time of unarmored thermocouples, the range of temperature measurement, how to use them, and how to use them.

Thermal response time of armored thermocouple

When the temperature changes in stages, the output of the thermocouple changes to 50% of the step change. The time required is called the thermoelectric response time.
The response time of the armored thermocouple should not be greater than the data in the following table: Unit: s

Diameter of armored thermocouple mm	Differentiation of the working end form of armored thermocouple		Response time of armored thermal resistance
	Response time of insulated armored thermocouple s	Response time of shell-type armored thermocouple s
Ф2.0	0.5	0.4	------
Ф3.0	1.2	0.6	3.0
Ф4.0	2.5	0.8	5.0
Ф5.0	4.5	1.2	8.0
Ф6.0	6.0	2.0	12.0
Ф8.0	8.0	4.0

Temperature range

category	Codename	Index number	Outer diameter of casing mm	Common temperature ℃	Maximum use temperature ℃	Allowable deviation
						Measuring range °C	Tolerance value
Platinum Rhodium 10-PlatinumWRPK		S	≥Φ3	1100	1200	0-1200	±1.5℃ or ±1.5%t
Nickel Chromium-Copper Nickel	WREK	E	≥Φ3	600	700	0-700	±2.5℃ or ±0.75%t
Nickel Chromium-Nickel Silicon	WRNK	K	≥Φ3	800	950	0-900	±2.5℃ or ±0.75%t
Copper-Copper Nickel	WRCK	T	≥Φ3	350	400	Less than -200	Not specified
						-40-350	±0.75%t
Iron-Copper Nickel	WRFK	J	≥Φ3	500	600	0-600	±2.5℃ or ±0.75%t

Verification method of armored thermocouple

The verification method of the metal melt rapid armored thermocouple verification device is as follows:
The device is mainly composed of a flat heating coil that can accommodate two quartz tubes at the ends of the tested couple, two armored thermocouples with the same shape as the tested couple, and a corresponding temperature control display output device. The verification method is to first use two calibrated thermocouples to find out the points in the flat heating coil that make the two calibrated couples have the same thermoelectric potential, and replace one of the calibrated couples with the tested couple. When other conditions remain unchanged, after the reading of the tested couple is stable, compare it with the reading of the calibrated couple to know whether the value of the tested couple is accurate. This method provides a laboratory verification method for rapid temperature measuring thermocouples, and can test and make a comprehensive evaluation of rapid temperature measuring thermocouples at multiple temperature points.

Its characteristics are:
a) The device is composed of a flat heating coil, a pair of calibrated armored thermocouples and a temperature control display output device.
b) The verification method is to first insert two calibrated thermocouples from the two ends of the heating coil opposite to each other, so that the hot ends of the armored thermocouple are in contact. By changing the position of the calibration thermocouple in the heating coil, the thermoelectric potentials of the two calibration thermocouples are the same. Replace one of the calibrated thermocouples with the tested fast thermocouple, and compare the thermoelectric potential of the calibrated thermocouple by reading its steady state thermoelectric potential to know the accuracy of the tested fast armored thermocouple.

Tips for using armored thermocouple

There are actually many techniques for using armored thermocouples.
1. It has bendable performance, except for the head, the thermal resistance can be bent in any direction. Therefore, it is suitable for detecting the temperature of more complicated and small equipment.
2. The armored thermocouple has good vibration resistance and impact resistance. Therefore, its life is longer than ordinary thermal resistance.
3. Armoured thermocouple has a long service life. Thermal resistance of the resistor due to armor used protective cap and twisting metal sleeve all-metal insulation, thermal resistance wire harmful media can not easily be eroded.
4. The explosion-proof thermal resistance passes through a junction box with a special structure, and the explosion of internal explosive mixed gas due to the influence of sparks or arcs is confined in the junction box.
5. The production site will not cause an explosion. Explosion-proof thermal resistance can be used for temperature measurement in places with explosion hazard in Bla-B3c class zone. The anti-corrosion thermal resistance is made of PTFE anti-corrosion material.
6. As an integral protective sleeve or two-section sleeve, the anti-corrosion treatment of this material can also be directly applied to the protective tube, which can be divided into three forms: spraying, sintering and sleeve sealing.
7. It is suitable for measuring in strong alkali and corrosive medium, with a temperature resistance of 250℃, and the fixed installation situation can also use the same PTFE fixed thread.
8. According to the measurement temperature range and side measurement object, select the appropriate thermal resistance model, specification and maintenance tube information.