The dimensions of acrylic do not change significantly over time: this is why many measuring instruments are made from acrylic. Vigilance should however be exercised when acrylic is used in combination with other materials, since it expands with increasing temperatures. An acrylic rod of one metre length will thus become 0.7 mm longer if the temperature rises by 10 degrees. When acrylic is subjected to pressure within a steel frame, it is highly likely that the acrylic will burst with a change of temperature.