ASTM C518 Steady-State Thermal Conductivity Properties Tester by
Heat Flow Meter
Description:
The popular way that using the heat flow meter to test the thermal
conductivity and resistivity, together with the computer can
achieve the auto inspection and report generation.
This testing method easy, quick and good repeatability, which is
suitable for the heat transferring R&D of the metal materials.
It can also used for the test of plastic, rubber, ceramic, glass,
graphite and other heat insulating material.
Standard:
ISO 8301 Thermal insulation -- Determination of steady-state
thermal resistance and related properties -- Heat flow meter
apparatus
GB/T 10295 Thermal insulation -- Determination of steady-state
thermal resistance and related properties -- Heat flow meter
apparatus
ASTM C518 Standard Test Method for Steady-State Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus
EN 12667 Thermal performance of building materials and products -
Determination of thermal resistance by means of guarded hot plate
and heat flow meter methods - Products of high and medium thermal
resistance;
Specification:
1. The area of heat conductivity: sheet sample 0.01-10W/mk,
accuracy less than 3%.
2. Thermal resistance measurement: 0.1~8 m2K/W
3. Sample dimensions: 100*100mm, thickness 5 ~20mm.
4. Cold surface: 10℃~ 50℃, digital displayer to detect the
temperature, 0.1 level accuracy. DPI 0.01℃.
5. Heat surface temp control: room temp.- 99.99℃, use high temp
digital displayer to detect the temperature, 0.1 level accuracy.
DPI 0.01 ℃. The flat type heater, two-way controllable.
6. Cold surface use water bath cooling.
7. Use computer to test automatically.
8. Use WPY heat flow meter, heat flow feature 23.26w/m2*mV.
9. Use Plexiglas’s wind cover, so that the whole test course can be
observed directly.
10. Cold and hot plate heat transferring area: 150×150(mm)
11. Cold and hot plate adjustable gap distance: 0-160(mm).
Test Procedure:
This test uses a Heat Flow Meter Apparatus (HFM). The Heat Flow
Meter consists of a cold plate and a hot plate that incorporate
heat flux transducers for measuring heat flow. The material to be
measured is placed between the two plates that are controlled to
different temperatures to create a heat flow from hot to cold
plate, which is measured by the transducers. The device is
calibrated against materials of known thermal conductivity and can
be used to measure flat materials in a wide range of thickness and
conductivity. Tests are commonly performed with a mean temperature
between 35ºF and 110ºF, with the most common being 75ºF. A
temperature difference of 40ºF – 50ºF is commonly used.
End Result:
The thermal conductivity (k-Value) and thermal resistance (R-Value)
are determined. These values can be used to determine energy losses
through a material. This test can be used to satisfy R-Value
regulations for insulation materials, such as the US Federal Trade
Commission’s “R-Value Rule” (10 CFR 460).
Special Notes:
This method can often be used as an alternative to ASTM C177, which
determines the same properties using a different device known as a
Guarded Hot Plate Apparatus (GHP).
