Thermal resistance PT100

Thermal resistance PT100Shanghai Instrument Third FactoryTemperature sensing element at 100 ℃Resistance value at time (R100）And it's at 0℃Resistance value R at time0The ratio: (R100/ R0）

Division number Pt100: A-level R0= 100±0.06Ω

B-grade R0= 100±0.12Ω

Index number Cu50: R0=50 ± 0.05 Ω

Thermal response time

When there is a step change in temperature, the time required for the output of the thermal resistor to change to 50% of the step change is called the thermal response time, which is T0.5express.

Thermistor nominal pressure

Thermal resistance PT100Shanghai Instrument Third FactoryGenerally refers to the external pressure (static pressure) that the protective tube can withstand at the working temperatureDurable and unbreakable. 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, placement depth, as well as the flow rate and type of the measured medium.

Small insertion depth of thermistor

︱min＝︱yuan+15D

︱Min - Small available insertion depth

︱yuan- Length of temperature sensing element

D - outer diameter of protective tube

natural influence

When measuring a current of 5mA through a thermal resistor, the measured resistance increment converted to temperature value should not exceed 0.30 ℃.

insulation resistance

The test voltage for insulation resistance at room temperature can be taken as 10 DC～100V at any value, with an ambient temperature of 15～Within the temperature range of 35 ℃, the relative humidity should not exceed 80%. The insulation resistance value at room temperature should not be less than 100MΩ

working principle

Industrial thermal resistors are divided into two categories: platinum thermal resistors and copper thermal resistors.

Thermistor measures temperature by utilizing the characteristic that a substance's own resistance changes with temperature. The heated part (temperature sensing element) of a thermal resistor is uniformly wound around a skeleton made of insulating material with thin metal wires. When there is a temperature gradient in the measured medium, the measured temperature is the average temperature in the dielectric layer within the range of the temperature sensing element.

Prefabricated thermistor mainly consists of a junction box, protective tube, terminal block, insulation sleeve, and temperature sensing element, and is equipped with various installation and fixing devices.

The temperature sensing element of WZP type platinum resistor is a platinum wire winding, and dual platinum resistors are mainly used in situations where two sets of display, recording, and regulating instruments are required to simultaneously detect the temperature at the same location. The temperature sensing element of WZC type copper resistor is a copper wire winding.

Model

Unified design type thermistor

Non fixed device type thermistor

Note: 1. Mark the "*" division mark for special specification ordering

2. Models 120 and 121 are splash proof junction boxes, while models 130 and 131 are waterproof junction boxes.

Thermal resistance length specification