WZPK-336SA armored thermal resistor is a temperature sensor that measures the temperature of a material as its temperature changes. When the resistance value changes, the working meter displays the temperature value corresponding to the resistance value. It is smaller than the assembled platinum resistor and is easy to bend. It is suitable for special occasions such as narrow pipes and quick response and miniaturization. It can automatically detect gas, liquid medium and solid surface in the temperature range of -200~600 °C, and can be directly connected with copper wire and secondary instrument. Because it has good electrical output characteristics, it can be a display instrument. Recorders, regulators, scanners, data loggers, and computers provide accurate input values. Product structure:
The structure of the armored thermal resistor is the same as that of the conventional thermal resistor except that the temperature measuring component, the insulating material and the protective sleeve of the five parts constitute the whole of the coffin.
Coffin (temperature measuring element, insulating material, protective sleeve): The temperature measuring element is a temperature sensing element and its inner lead for the thermal resistance; magnesium oxide is used between each thermal resistance lead and between the protective sleeve and the protective sleeve As insulating material; protect the insulating material and temperature measuring element with a metal tube. The coffin process uses temperature measuring components, insulating materials and protective sleeves to become a non-removable and flexible compact body. The coffin is the base material for manufacturing armored thermal resistors. The coffin cannot be directly used for temperature measurement. The measuring end and the simple terminal can be used as a base armored thermal resistor. Working principle:
Armored thermal resistance is a measure of the temperature of a material as its temperature changes. When the resistance value changes, the working meter displays the temperature value corresponding to the resistance value. The armored thermal resistance is a temperature sensor, which is smaller than the assembled thermal resistance, easy to bend, and has good shock resistance. It is suitable for installation where the assembled thermal resistance cannot be installed. WZPK series armored thermal resistance adopts the introduction of thermal resistance to measure temperature. Components, therefore, have the advantages of accuracy, sensitivity, fast thermal response time, stable quality, and long service life.
The armored thermal resistance outer protective sleeve is made of stainless steel and filled with high-density oxidized material insulator. Therefore, the armored thermal resistor has strong anti-pollution performance and mechanical strength, and is suitable for installation in harsh environments. Features:
(1) High measurement accuracy;
(2) The diameter is small and the length is limited;
(3) Imported or domestic thin film resistor components, reliable and stable performance;
(4) The armored thermal resistance is usually composed of the main components such as the armored platinum thermal resistance temperature sensing element, the mounting fixture and the wiring device, and the thermal response time is small, and the dynamic error is reduced;
(5) The outer protective tube of the armored resistor is made of stainless steel and filled with high-density metallurgical grade magnesia oxide insulator. Therefore, it has strong anti-pollution and excellent mechanical strength, and is suitable for installation in harsh environments. Technical Parameters:
Product performance standards:
Normal temperature insulation resistance;
The thermal resistance is 15-35 ° C at ambient temperature, the relative humidity is not more than 80%, and the insulation resistance between the electrode and the outer sleeve of the test voltage is 10 - 100 V (DC) > 100 MΩ. Thermal response time:
When the temperature changes stepwise, the output of the thermal resistance changes to 50% of the step change, and the time required is called the thermal response time. The experimental voltage of the normal temperature insulation resistance can be any value of DC 10-100V, the ambient temperature is in the range of 15-35 °C, the relative temperature should be no more than 80%, and the measured current through the armored thermal resistance is not more than 5 mA. Installation and use:
The armored thermal resistance should be installed near the furnace or too close to the heating body. It should be installed in a place where there is no vibration or vibration, and it is easy to construct and maintain. The mounting position should be as vertical as possible, but it must be tilted when there is a flow rate. The junction box outlet should be facing down.
Armored thermal resistance should be wired as specified, usually in three-wire system. The connecting wire shall be insulated (preferably open) copper wire, the cross-sectional area shall be ≥ 1.0 mm 2 , and the resistance of the wire shall be registered as specified in the display instrument.
The thermal resistance changes from the thermal inertia to the temperature change. To eliminate the error caused by it, the outer diameter of the thermal resistance protection tube should be reduced as much as possible, and the insertion depth of the thermal resistance should be appropriately increased to increase the thermal resistance of the thermal resistance.
Always check the condition of the protective tube and find that oxidation or deformation should be taken immediately and periodically verified. How to choose:
According to the temperature range selection: the thermocouple is generally selected above 500 °C, and the thermal resistance is generally selected below 500 °C; according to the measurement accuracy: the thermal resistance is selected with higher precision, and the thermocouple is not required for precision;
According to the measurement range: the temperature measured by the thermocouple generally refers to the "point" temperature, and the thermal resistance is generally measured as the space average temperature; the 2-wire thermal resistance wiring is simple, but the additional error of the lead resistance is required. Therefore, it is not suitable to manufacture a class A precision thermal resistance, and the lead wires and wires should not be too long in use. The wire system can eliminate the influence of lead resistance, and the measurement accuracy is higher than the 2-wire system. As a process detection component, it is the most widely used. The wire system not only eliminates the influence of the lead resistance, but also eliminates the influence of the resistance when the resistance of the connecting wire is the same. For high-precision measurement, a 4-wire system is required. Product difference:
1) Ordinary type thermal resistance From the temperature measurement principle of the thermal resistance, the change of the measured temperature is directly measured by the change of the resistance of the thermal resistance. Therefore, the change of the resistance of various wires such as the lead wire of the thermal resistor body will be given. Temperature measurement has an impact.
2) The armored thermal resistor is a solid body composed of a temperature sensing element (resistor), a lead wire, an insulating material, and a stainless steel bushing. Its outer diameter is generally φ2--φ8mm, and the minimum is φ0.25mm (铠) Install the minimum outer diameter of the thermal resistance, K type is φ0.25mm, E type is φ1.0mm). Compared with ordinary type thermal resistance, it has the following advantages: 1 small volume, no air gap inside, thermal inertia, small measurement lag; 2 good mechanical properties, vibration resistance, impact resistance; 3 can bend, easy to install; 4 service life long.
3) The end face thermal resistance temperature sensing element is wound by a specially treated resistance wire and is closely attached to the end face of the thermometer. Compared with the general axial thermal resistance, it can reflect the actual temperature of the tested end face more correctly and quickly, and is suitable for measuring the end face temperature of the bearing bush and other parts.
4) Explosion-proof type thermal resistance is limited to the explosion caused by sparks or arcs in the explosion-mixed gas inside the casing through a special-structure junction box, and the production site will not lead to an explosion. Explosion-proof thermal resistance can be used for temperature measurement in explosive areas where the Bla--B3c level is explosive.
5) Anti-corrosion thermal resistance is made of PTFE anti-corrosion material. As an integral protective sleeve or two-section casing, it can also be used as anti-corrosion treatment on the protection tube. It can be sprayed, sintered and sleeve sealed. It is suitable for measurement in corrosive medium with strong alkali. It can withstand temperature of 250 °C. It can also be fixed thread with fixed PTFE material, fixed flange (contact interface surface) or ferrule thread for fixed installation. Full anti-corrosion can be achieved with PVC junction box or 316L junction box. A variety of installation methods, a variety of diameters, any choice.
6) Special temperature measuring instrument for hot-sleeve type thermal resistance thermal power generating unit. The general temperature measuring instrument in the power station can be selected in the General Category of this selection sample. The design of the product is based on the American EBASCO specification, and fully considers the opinions of design institutes and power station users. It adopts the internationally popular separation protection tube structure, and elastically compresses the measuring component method to add a high temperature limit of 650 °C. Install platinum resistance.
1. All armored components are used, shockproof and compressive, high stability and long service life.
2. The bottom of the armored component and the protective tube is an elastic pressing structure, which shortens the thermal response time and further improves the earthquake resistance.
3. Large cavity junction box and novel wiring device make the wiring more convenient and reliable.
4. The thermocouple main body and the protection tube are separated structures, and the temperature measuring components can be quickly replaced without stopping the machine.
5. The whole protection tube for deep blind hole processing has uniform wall thickness at the end, no welding stress and hidden danger of crystal dielectric corrosion, so it is resistant to pressure, impact, reliable and long life, which can ensure the safe operation of the unit.
6, the overall stretch of 650 ° C high temperature armored palladium platinum resistance components, its shock resistance and upper temperature limit can meet the high-precision and high reliability of the main unit steam temperature. Precautions:
It is made of cold metal extraction and silver spiral processing by a combination of metal maintenance pipe, insulation data and resistor body. The resistor body in the armored type of thermistor is made of a platinum-plated thermocouple ceramic or a glass crucible holder, and the lead wire is usually a steel wire or a silver wire.
Armored thermal resistors have the following characteristics:
(1) The thermal inertia is small, and the reaction speed is fast. For example, the ordinary platinum resistance of the maintenance tube diameter is 2mm, the time constant is 25s; and the diameter of the metal sleeve is twisted. 0mm armored thermal resistance, the time is only effective. 5 . about.
(2) With bendability, the armored thermal resistor can be bent in any direction except the head, so it is suitable for the construction of the temperature side Ao of the small device.
(3) It has good vibration and impact resistance.
(4) Using a long life, the resistor body of the armored thermal resistor is not easily protected by the harmful medium due to the twisted cover of the iron-insulated material and the maintenance of the metal sleeve, so its thermal resistance and life Longer than ordinary thermal resistance.
When using the thermal resistance, pay attention to the following items:
(1) According to the measurement temperature range and the measurement object, select the model, specification and maintenance pipe data of the appropriate thermal resistance.
(2) The maximum operating temperature and working pressure of the thermal resistance shall not exceed the rated value of the thermal resistance.
(3) If the thermal resistance needs to be used in corrosive media, a maintenance pipe made of stainless steel should be used.
(4) The length of the sensitive component of most thermal resistors is about 120mm. When selecting the insertion depth of the thermal resistor, it should be considered that the thermal resistor can only measure the uniformity of the measured medium in the left-right range of the sensitive component.
(5) When wiring the RTD, first open the junction box and then wire it. There are two methods of wiring: two-wire and three-wire. The advantage of the three-wire connection is that it prevents the indication error of the meter from appearing due to the resistance of the bimetal thermometer.
(6) The connecting wire of the thermal resistance and the display instrument shall be insulated copper wire, and the compensation wire of the thermocouple shall not be used. The resistance value of the copper wire should be selected according to the data of the technical condition of the instrument, which is usually 2-50. The resistance value of the wire can be adjusted by the DC equalization bridge.
(7) A thermal resistor cannot be used in parallel with two display instruments, as long as the double-armed thermal resistor can be used together with two display instruments.
(8) The thermal resistance and its accessories must be stored in the center of the tungsten-rhodium thermocouple without vibration and collision when it is not used. The most suitable storage conditions are: ambient temperature 10-35 ° C; relative humidity is not more than 80%; ambient air should not contain substances that may form corrosion of the parts of the thermal resistance.