Sheathed Resistance Thermometer

WZ □ K Series - Sheathed Resistance Thermometer 

Overview

Sheathed thermocouples are temperature sensors that have a smaller diameter than assembly-type platinum resistance thermometers, are easily bendable, and have good shock resistance. They are suitable for installation in situations where assembly-type resistance thermometers cannot be installed. Our company's WZPK series sheathed thermocouples use imported thermocouple temperature sensing elements, thus possessing advantages such as precision, sensitivity, fast thermal response time, stable quality, and long service life.

The outer protective sheath of the sheathed thermocouple is made of stainless steel, filled with a high-density oxide insulation material. Therefore, it has strong anti-pollution performance and excellent mechanical strength, suitable for installation in harsh environments. Sheathed thermocouples can be used to measure temperatures ranging from -200 to 500°C and can be directly connected to copper conductors and secondary instruments. Due to its good electrical output characteristics, it can provide precise temperature change input signals for display meters, recorders, regulators, scanners, data loggers, and computers.

 

Working Principle

The resistance of the thermocouple wire changes with temperature. The display meter will indicate the temperature value corresponding to the resistance value generated by the thermocouple.

 

 

 

Technical Specifications:

The ratio of the resistance value of the resistance thermometer sensing element at 100°C (R100) to its resistance at 0°C (R₀), denoted as R₁₀₀/R₀

Pt100: Class A R₀ = 100 ± 0.06Ω  Class B R₀ = 100 ± 0.12Ω

W₁₀₀ = R₁₀₀/R₀ = 1.3851

 

Measurement Range:

Model	Index	Range(℃)	Accuracy Class	Allowable deviation △ t℃
WZPK	Pt100	-200 ~ 500	Class A	-200 ~ 650℃ ±(0.15 + 0.002|t|)
			Class B	-200 ~ 800℃ ±(0.30 + 0.005|t|)
Note:In the equation, "t" represents the absolute value of the actual measured temperature of the sensing element.

Nominal Pressure:

Generally refers to the static external pressure that the protective tube can withstand at room temperature without rupturing. The test pressure is usually 1.5 times the nominal pressure. In fact, the allowable nominal pressure is not only related to the material, diameter, and wall thickness of the protective tube but also to its structural form, installation method, immersion depth, and the velocity and type of the measured medium.

Thermal Response Time:

The time required for the output of a resistance thermometer to change to 50% of a step change in temperature is called the thermal response time, denoted by τ_0.5.

Resistance of Thermal Resistance Insulation:

The test voltage for room temperature insulation resistance can be any DC value from 10 to 100V, with an ambient temperature ranging from 15 to 35°C and a relative humidity not exceeding 80%. The insulation resistance value at room temperature should not be less than 100MΩ.

Allowable Current through the Resistance Thermometer:

The maximum measurement current through the sheathed resistance thermometer does not exceed 5mA.

 

Classification of Sheathed Thermocouples:

Terminal Box Type:

 

 

Installation Fixing Type

Clamp Bolt Type

 

Clamp Flange Type