• Fundamentals of diffusion: Fick‘s law
  • Derivation of the calculation formula for the diffusion coefficients for the given experimental conditions
  • Determination of the diffusion coefficient for the mass transport in liquid


  • Investigation of diffusion in liquids
  • Transparent tank with magnetic stirrer, conductivity meter and U-tube with capillaries for investigating diffusion in aqueous solutions
  • Heater with controller and sensor for adjusting the temperature in the water bath

Due to changes in concentration, microscopic mass transfer of particles like atoms, molecules, and ions occurs through diffusion. It is critical to a number of processes. Diffusion, for instance, can assemble the components of chemical reactions, and it sometimes acts as the process’s rate-limiting phase. The CRE-3301A has a feature for diffusion in liquids. A concentrated salt solution is used to study diffusion in liquids. A U-shaped tube holding the solution contains a disc at one end with a number of vertical capillaries. The disc with the capillaries is positioned below the water’s surface by submerging the U-tube into a tank filled with demineralized water. The salt ions are produced by the concentration gradient between the solution and the water. The ions only flow in one dimension thanks to the capillaries. The presence of a stirrer in the tank prevents concentration variations in the tank by preventing the salt concentration from rising close to the disc. The amount of salt in the tank is measured using a conductivity meter.


Technical Data

  • Tank with stirrer: approx.
  • 1000mL

Magnetic Stirrer with heater

  • Speed stirrer: 0~500rpm
  • Heater Power: approx. 300W
  • Magnetic stirrer bar: 1

Diffusion Tube

  • Type: U-Tube
  • Capillaries: 250~300
  • Diameter: 1mm
  • length: 5~8mm

Conductivity Meter

  • Range: 0~2000uS/cm
  • Graduation: 1uS/cm

Measuring ranges

  • Temperature: 100~400°C
  • Conductivity: 0~200mS/cm

Software: CRE-3301ASW (optional)

DAQ software specially designed in National Instrument™, LABVIEW™ environment to measure and calculate the results of apparatus. The software is optional and while using software a set of electronic sensors are included. Software can be run with any Windows™ environment.

Scope of Delivery

1 experimental unit for diffusion in liquids, 1 U-tube with capillaries, 1 display and control unit, 1 conductivity meter, 1 magnetic stirrer with heater, 1 stopwatch, 1 set of instructional material