Instruments suitable for measuring the osmotic strength of a solution, colloid, or compound, or for determining the average molecular weight of a sample. Products include accessories and replacement parts for osmometers.

Osmometers and micro-osmometers (osmotic meters) are devices for measuring the osmolality (osmotic concentration or osmotic strength) of aqueous solutions. Osmolality is defined as the total concentration of all osmotically active dissolved solutes present in a given volume of solution. Osmolality is usually measured in mOsm/L or Osm/L.

Modern, automated electronic osmometers offer user-programming and digital displays and can analyze very small volumes of samples down to 20 µL.

What are the Different Types of Osmometers?
Different osmometers work based on different operating principles:
• Freezing point osmometers: industry-preferred models; provide the greatest accuracy and precision since the freezing point of water is depressed in proportion to the level of dissolved solute
• Vapor pressure osmometers: avoid issues associated with high viscosity or suspended particulates that may interfere with freezing point depression
• Other: osmometers based on the principles of specific gravity, refractive index, semi-permeable membrane flow or conductivity; are less favored and are considered less reliable

Most osmometers are supplied with a range of calibration standards and reference solutions (osmometer controls) and osmometer accessories.

How Are Osmometers Used in the Lab?
Osmometers are key items of equipment in a range of laboratory environments:
• Clinical chemistry: for testing whole blood, serum, plasma, urine and other body fluids for metabolic and electrolytic disorders and intoxication
• Pharmaceutical industry: bioprocess monitoring at critical points during manufacturing
• Organic and inorganic chemistry: to determine the average molecular weight of polymers or other unknown compounds or mixtures
• Other biology applications: analysis of plant saps, hydroponic or cell culture media