Pressure experiment

<p>Pressure experiments are <a href="/facts/Experiment/esltM54f">experiments</a> performed at <a href="/facts/Pressure/eyc37GRG">pressures</a> lower or higher than <a href="/facts/Atmospheric_pressure/wJLMSaVG">atmospheric pressure</a>, called low-pressure experiments and high-pressure experiments, respectively. Pressure experiment are necessary because substances behave differently at different pressures. For example, <a href="/facts/Water/0lkXnJPK">water</a> boils at a lower <a href="/facts/Temperature/QyGe4gmj">temperature</a> at lower pressures. The equipment used for pressure experiments depends on whether the pressure is to be increased or decreased and by how much. A <a href="/facts/Vacuum_pump/QTkV5dXr">vacuum pump</a> is used to remove the air out of a <a href="/facts/Vacuum/BTk3goyV">vacuum</a> vessel for low-pressure experiments. High-pressures can be created with a <a href="/facts/Piston-cylinder_apparatus/8A9e3V9z">piston-cylinder apparatus</a>, up to 5 <a href="/facts/Pascal_(unit)/Am1To2Qm">GPa</a> (50 000 bar) and ~2000 <a href="/facts/Celsius/okAEu1CA">°C</a>. The piston is shifted with <a href="/facts/Hydraulics/KSIqLovc">hydraulics</a>, decreasing the volume inside the confining cylinder and increasing the pressure. For higher pressures, up to 25 GPa, a <a href="/facts/Anvil_press/4cMorcG8">multi-anvil</a> cell is used and for even higher pressures the <a href="/facts/Diamond_anvil_cell/vpsaLRrr">diamond anvil cell</a>. The diamond anvil cell is used to create extremely high pressures, as much as a million <a href="/facts/Atmosphere_(unit)/aTbYALII">atmospheres</a> (101 GPa), though only over a small area. The current record is 560 GPa, but the sample size is confined to the order of tens of micrometres (10−5 m).
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Pressure experiment open-in-new

Pressure experiment