Physics Lab Equipment

    LETI-50-1.jpg

Schematic diagram of apparatus panel      LETI-50-2.png

Measurement of  thermal resistance using constant current method

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Measurement of  thermal resistance using DC bridge method

    LETI-50-4.png   Temperature properties of  3 types of  thermal resistances

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PN-junction temperature sensor

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Current-mode integrated temperature sensor

LETI-50 Temperature Properties of Various Temperature Sensors

LETI-50 Temperature Properties of Various Temperature Sensors

Introduction


Temperature plays an important role in scientific research and industrial production process where temperature sensing and control is widely required. Temperature sensors are made of materials such as metals and semiconductors based on their temperature-related properties.


This apparatus consists of a precise temperature control system, a constant-current source, a DC bridge, DC power supplies, a digital voltmeter, and a set of temperature sensors including Pt100 thermocouple, NTC1K thermistor, PN-junction temperature sensor, AD590 current-mode integrated temperature sensor, and LM35 voltage-mode integrated temperature sensor.


The heating device of the apparatus adopts a high accuracy dry-well thermostatic furnace. The accuracy of temperature control is assured by a temperature control system P.I.D. The control accuracy is up to ± 0.1 °C at a preset temperature point and ± 0.3 °C for the entire temperature measurement range. Furthermore, using the internal setting of "UU" fine-tuning, temperature control accuracy can be up to ± 0.1 °C in the entire temperature range. The thermostatic block of the dry-well furnace is made of pure copper, which has excellent thermal conductivity that results in a very good temperature consistency for the four dry wells as well as the central dry well. Compared with a thermostatic tank, this kind of dry well is compact and does not need a blender. The power supply of the heater is DC 24V with current up to 2A (total power 48W). The time for heating the dry well furnace from room temperature to 100 °C is about 10 minutes. At the same time, in order to quickly repeat an experiment, the apparatus is equipped with a fan that can quickly reduce the temperature inside the dry well.


By measuring the property variations with temperature change of a few commonly used temperature sensors, the working principle of these temperature sensors can be understood. Using this apparatus, the following experiments can be conducted:

 

1. Learn to use constant current method to measure thermal resistance;

2. Learn to use DC bridge method to measure thermal resistance;

3. Measure temperature properties of a platinum resistance temperature sensors (Pt100);

4. Measure temperature properties of a thermistor NTC1K (negative temperature coefficient) ;

5. Measure temperature properties of a PN-junction temperature sensor;

6. Measure temperature properties of a current-mode integrated temperature sensor (AD590);

7. Measure temperature properties of a voltage-mode integrated temperature sensor (LM35).


The instruction manual contains experimental configurations, principles, step-by-step instructions, and examples of experiment results. Please click Experiment Theory and Contents to find more information about this apparatus.


Specifications

DescriptionSpecifications
Bridge source+2 V ± 0.5%, 0.3 A
Constant current source1 mA ± 0.5%
Voltage source+5 V, 0.5 A
Digital voltmeter0 ~ 2 V ± 0.2%, resolution, 0.0001V; 0 ~ 20 V ± 0.2%, resolution 0.001 V
Temperature controllerresolution: 0.1 °C
stability: ± 0.1 °C
range: 0 ~ 100 °C
accuracy: ± 3% (± 0.5% after calibration)
Power consumption100 W


Part List

DescriptionQty
Main unit1
Temperature sensor6 (Pt100 x2, NTC1K, AD590, LM35, PN Junction)
Jumper wire6
Power cord1
Experimental instruction manual1


    LETI-50-1.jpg

Schematic diagram of apparatus panel      LETI-50-2.png

Measurement of  thermal resistance using constant current method

    LETI-50-3.png

Measurement of  thermal resistance using DC bridge method

    LETI-50-4.png   Temperature properties of  3 types of  thermal resistances

   LETI-50-5.png

PN-junction temperature sensor

     LETI-50-6.png

Current-mode integrated temperature sensor

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