Control Panel Cooling units Technical Information
3-4. Thermal expansion coefficient
(1) If there is a difference of 10℃, there is a difference of over 0.1mm per 1m in iron.
Main materials list of thermal expansion coefficient
(2) Comparison in thermal expansion coefficient between general air conditioning and precision air conditioning
There is a significant difference in the size of the substances due to temperature changes between general air conditioning and precision air conditioning.
Under general air conditioning, the ambient temperature where the products, examination and research materials, and manufacturing and testing machines are placed changes significantly due to outside temperature or such.
Those materials and the equipment change their size due to thermal expansion from this temperature change.
The precision air conditioning is available to adjust its temperature ±0.1℃, compared to the general air conditioning, which controls its temperature ±5℃ from preset.
Here, the general air conditioning is set at 10 ℃ and the precision air conditioning is set at 0.2 ℃ throughout the year. Compare the displacement in the case where the materials' temperature becomes the same as the ambient temperature.
Thermal expansion ratio under general air conditioning and precision air conditioning
(Unit: mm, the length of the material is 1m)
| Material | Under general air conditioning | Under precision air conditioning |
|---|---|---|
| Iron | 0.117 | 0.00234 |
| Aluminum | 0.238 | 0.00476 |
| Gold | 0.142 | 0.00284 |
| Silver | 0.189 | 0.00378 |
| Copper | 0.168 | 0.00336 |
| Zinc | 0.33 | 0.0066 |
| Chromium | 0.082 | 0.00164 |
| Tin | 0.2 | 0.004 |
| Lead | 0.291 | 0.00582 |
| Nickel | 0.128 | 0.00256 |
| SUS304 | 0.173 | 0.00346 |
| SUS430 | 0.104 | 0.00208 |
| Solder | 0.25 | 0.005 |
| Polyester | 1 | 0.02 |
| Polyethylene | 1.8 | 0.036 |
| PVC | 0.8 | 0.016 |
| Polystyrene | 0.8 | 0.016 |
| Polycarbonate | 0.7 | 0.014 |
| Rubber | 1.1 | 0.022 |
| Polyimide | 0.54 | 0.0108 |
| Epoxy | 0.62 | 0.0124 |
| Carbon fiber | 0 | 0 |
| Glass | 0.09 | 0.0018 |
| Carbon steel | 0.108 | 0.00216 |
| Ceramic (silicon carbide) | 0.044 | 0.00088 |
| Silicon | 0.026 | 0.00052 |
Comparison in thermal expansion coefficient between general air conditioning and precision air conditioning
Suppressing the temperature change can reduce the change in the size of the substances to this level.
Temperature change all year
If the general air conditioning is =±5℃ : the precision air conditioning is =±0.1℃, the change per 1m of material is...
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