Transient plane heat source method for thermal conductivity tester

ZHDL-S Transient Plane Heat Source Thermal Conductivity Meter

1、 Introduction

ZHDL-S is a thermal conductivity tester developed using transient planar heat source technology (TPS), which can be used to test the thermal conductivity performance of various types of materials. The transient planar heat source method is the latest type of method for studying thermal conductivity performance, which has taken measurement techniques to a whole new level. The ability to quickly and accurately measure thermal conductivity when studying materials provides great convenience for enterprise quality monitoring, material production, and laboratory research. The instrument is easy to operate, the method is simple and easy to understand, and it will not cause damage to the tested sample.

2、 Working principleTransient plane heat source method for thermal conductivity tester

Transient planar heat source technology (TPS) is a novel method for measuring thermal conductivity, developed by Professor Silas Gustafsson from Chalmer University of Technology in Sweden based on the hot wire method. The principle of determining the thermal properties of materials is based on the transient temperature response generated by a disc-shaped heat source with step heating in an infinite medium. Using thermal resistant materials to create a flat probe that serves as both a heat source and a temperature sensor. The thermal resistance coefficient of an alloy is linearly related to temperature and resistance, which means that by understanding the change in resistance, the heat loss can be determined, thereby reflecting the thermal conductivity of the sample. The probe of this method is a continuous double helix structure thin film formed by etching conductive alloy, with a double-layer insulating protective layer on the outer layer and a very thin thickness, which gives the probe a certain mechanical strength and maintains electrical insulation with the sample. During the testing process, the probe is placed in the middle of the sample for testing. When current passes through the probe, a certain temperature rise is generated, and the heat generated simultaneously diffuses to the samples on both sides of the probe. The speed of thermal diffusion depends on the thermal conductivity characteristics of the material. By recording the temperature and the response time of the probe, the thermal conductivity can be directly obtained from a mathematical model.

3、 Test objectTransient plane heat source method for thermal conductivity tester

Metals, ceramics, alloys, ores, polymers, composites, paper, fabrics, foamed plastics (thermal insulation materials and plates with flat surfaces), mineral wool, cement walls, glass reinforced composite plates CRC, cement polystyrene plates, sandwich concrete, glass reinforced steel panel composite plates, paper honeycomb plates, colloids, liquids, powders, granular and paste solids, etc., have a wide range of test objects.

4、 Instrument features

1. Instrument reference standard: ISO 22007-2 2008

2. The testing scope is wide, the testing performance is stable, and it is at the forefront among similar instruments in China;

3. Direct measurement, with a testing time of about 5-160 seconds that can be set, can quickly and accurately measure the thermal conductivity, saving a lot of time;

4. Will not be affected by contact thermal resistance like the static method;

5. No special sample preparation is required, and there are no specific requirements for sample shape. Solid blocks only need a relatively smooth sample surface and a length and width that is at least twice the diameter of the probe;

6. Performing non-destructive testing on samples means that they can be reused;

7. The probe adopts a double helix structure for design, combined with a dedicated mathematical model, and uses core algorithms to analyze and calculate the data collected on the probe;

8. The structure design of the sample table is clever, easy to operate, suitable for placing samples of different thicknesses, and simple and beautiful at the same time;

9. The data acquisition on the probe uses imported data acquisition chips, which have high resolution and can make the test results more accurate and reliable;

10. The control system of the host uses ARM microprocessors, which have faster processing speed than traditional microprocessors, improving the system's analysis and processing capabilities, and resulting in more accurate calculation results;

11. The instrument can be used for the determination of thermal properties such as block solids, paste solids, granular solids, colloids, liquids, powders, coatings, films, insulation materials, etc;

12. Intelligent human-machine interface, color LCD display, touch screen control, easy and simple operation;

13. Powerful data processing capabilities. A highly automated computer data communication and report processing system.

5、 Technical parameters:

Test range: 0.0001-300 W/(m * K)

Measurement sample temperature range: room temperature -130 ℃

Probe diameter: probe 1 7.5mm; probe 2 15mm; probe 3 30mm

Accuracy: ± 3%

Repetitive error: ≤ 3%

Measurement time: 5-160 seconds

Power supply: AC 220V

Whole machine power: ＜ 500w

Sample temperature rise<15 ℃

Test sample power P: Probe 1 power 0<P<1w;

Probe 2 power 0<P<14w

Probe 3 power 0<P<14w

Sample specification: Single sample measured by probe 1 (15 * 15 * 3.75mm)

Single sample measured by probe 2 (30 * 30 * 7.5mm)

Single sample measured by probe No. 3 (60 * 60 * 2mm)

Note: Probe 1 measures thin low conductivity materials, while probe 3 tests materials with a thermal conductivity of 50 or higher; If the surface of the tested sample is smooth, flat, and sticky, the sample can be stacked.

6、 Compared to other methods, it is faster, simpler, and more comprehensive

7、 The operation method is simple and easy to understand