Using a Horizontal Push Rod Dilatometer to Measure the Thermal Expansion Coefficient and Softening Point of Glass

The thermal properties of glass materials, including the thermal expansion coefficient (CTE), glass transition temperature, and softening point, are key parameters that characterize the performance of glass materials. The push rod dilatometer can conveniently and quickly test these properties. Our company's DIL 0809 PC dilatometer integrates numerous advantages: it is very easy to operate, has a wide range of applications, and excellent testing performance. The optimized design of the differential sensor allows the instrument to provide ultra-high reproducibility even without additional temperature control equipment. This instrument measures the dimensional changes of the sample as a function of temperature or time under a specific temperature program and with a load close to zero. The instrument features a horizontal design, which makes the furnace easy to operate and simplifies sample loading. Even samples of non-ideal dimensions can be easily placed into the grooves of the tubular sample holder. The thermocouple is positioned close to the sample for temperature measurement, ensuring the repeatability of temperature measurements. Additionally, the c-DTA function of this instrument allows it to measure the heat absorption and release effects of the sample while testing the thermal expansion coefficient. The specific experimental operation steps are as follows: 1. Prepare the test sample into a cylinder of Φ(6–8)×50 or a square of (6–8)×(6–8)×50 using a cutting machine or other tools as required by the experiment; due to different preparation processes, the actual length of the test sample may be slightly less or more than 50mm, in which case the actual length of the sample should be recorded for reference. 2. Turn on the power of the instrument, open the furnace, expose the sample holder, and place the sample in the designated area of the sample holder. The sample should be parallel to the sample holder and in good contact with the end face of the displacement push rod (note: the steps are reversed when taking the sample). 3. Observe the displacement display instrument to check if its value is around 2000; if it is too high or too low, adjust the displacement adjustment knob, and if the data is suitable, this step can be skipped. (Note: Some instruments do not have this function.) 4. Push the furnace so that the sample holder is in the center of the heating zone of the furnace, then press the 'Start Work' button on the instrument panel. At this point, the green working indicator light on the panel will light up, and then let the instrument sit for 5 to 10 minutes to allow the displacement display to stabilize. 5. In the parameter setting window of the testing software, you can directly set the temperature control curve through the 'Temperature Control Curve' item. After filling in the sample length and termination temperature experimental parameters, click the 'Start Test' button in the 'Test Control' section. At this point, the instrument will start to heat up and automatically record and process data. The testing software will automatically handle the calculation of the average linear expansion coefficient of the test sample at each temperature point. The image shows the analysis report of the glass samples produced by the Korean E-glass company, measured by our technicians.

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