There are several different techniques employed in osmometry:
- Vapor pressure depression osmometers determine the concentration of osmotically active particles that reduce the vapor pressure of a solution.
- Membrane osmometers measure the osmotic pressure of a solution separated from pure solvent by a semipermeable membrane.
- Freezing point depression osmometer may also be used to determine the osmotic strength of a solution, as osmotically active compounds depress the freezing point of a solution.
Osmometers are useful for determining the total concentration of dissolved salts and sugars in blood or urine samples. Osmometry is also useful in determining the molecular weight of unknown compounds and polymers.
- Clifton nanolitre osmometer, an example of a freezing point depression osmometer.