School of Physics Lecture Demonstration Manual

Hf-1 Critical Point of Ether

Published: Monday 13 March 2006 - Updated: Monday 28 March 2011


To demonstrate the disappearance of the liquid-vapor boundary (the meniscus) at the critical point for ether.



Click on pictures to enlarge.

Critical Point of Ether Diagram


The critical point apparatus consists of a glass tube containing a small amount of ether. The tube is surrounded by a heating element that is connected to a 12 Volt power supply. The apparatus is placed on the Portalab projector and the meniscus made clearly visible by focussing.

Safety notes

Electrical safety 

Sharps Safety 


top of page