Schematic Diagram Diagram 1: The basic setup of coulter counter method. Test tube containing conducting fluid placed in the beaker containing same conducting fluid. Orifice in the test tube connect the circuit. Electrodes are placed in beaker and test tube and voltage is applied. Vacuum is applied in the test tube to allow fluid movement from beaker to test tube. Counting circuit will calculate the amount of particle and pulse height analyser will measure the particle size.
Principle of Operation:
Coulter Counter method is a technique that is able to measure the size and count the particles of experimented item suspended in the electrolyte using coulter counter instrument.
For measurement of the amount of particle, coulter counter operates by measuring the changes in the current intensity between two electrodes that submerged in the suspension of particles in conducting fluid. The conducting fluid is flow between anode and cathode through a small hole called as orifice. Presence of a particles in the orifice cause changes in resistant. Following the Ohm’s formula: Intensity = Voltage / Resistant.
The changes in resistance is also related with particle diameter where larger …show more content…
One of the advantages is this method is able to measure transparent particle as it need only for the particle to be volume occupied at the orifice. Second, this technique is very sensitive, having a good linearity and reproducibility (Rhyner, 2011). Third, this technique is able to measure wide range of particle size from 0.4µm up to 1200µm, however, with different orifice setting. Another advantage of Coulture counter method is usage of it in pharmaceutical science is well established particularly in measurement of crystal growth in the suspension, counting particulates in parenteral formulation and changes of poorly water-soluble particle size in dissolution (Storer & Ymen,