How are Ultrafine Bubbles measured?

Laser diffraction scattering method

When the light hits a particle, the light is either diffracted or scattered, and the intensity pattern of diffraction/scattering depends on the particle size. The intensity pattern (intensity distribution), which varies depending on the diffraction/scattering angle, can be observed. Particle size distribution can therefore be measured with Fraunhofer diffraction equation and/or Mie scattering theory.

Laser diffraction scattering method

Particle tracking analysis method

With particle tracking analysis method using NTA (Nano Tracking Analysis) technology, the Brownian motion of nano particles in liquid can be observed in real time. Because the speed of particle depends on the diameter, the particle size distribution graph of diameter and number of particles can be obtained by measuring the Brownian motion pattern.

Particle tracking analysis method

Resonance mass measurement method

Resonance mass measurement method is an innovative method to detect and count the number of invisible particles in the sample liquid, to measure the size, weight, and distribution of particle. The MEMS (Micro Electro-Mechanical Systems) sensor with a resonant cantilever equipped with the micro fluid channel is located in the center of a measuring device. When a particle in diameter of 50nm to 5µm passes through the fluid channel, the resonant frequency of cantilever changes, and the weight of suspended particle, dry weight, and particle diameter can be obtained.

Resonance mass measurement method 1

Resonance mass measurement method 1

Resonance mass measurement method 2 (Archimedes)

Resonance mass measurement method 2 (Archimedes)

Electrical resistance method

In electrical resistance method, Coulter theory is utilized to measure the particles. The change in electrical resistance between the two poles, when a particle passes through a pore, is measured. The electrical resistance is precisely proportional to the volume of particle passing through the pore. Because the volume of sample suspension passing through the pores is closely supervised, the volume, diameter, and concentration of particles can be measured with a high degree of accuracy. Measuring the particle distribution at ultra-high resolution, and measuring the concentration (number) of coarse particles (foreign particles and aggregated substance) are possible as well.

Electrical resistance method

Dynamic light scattering method

In dynamic light scattering method, laser light is radiated to the particles in the solution to observe the scattered light with a photon detector. The scattered lights interfere with each other as seen in Young's light interference experiment. The particles are constantly moving due to Brownian motion, and the intensity distribution is also fluctuating constantly, due to the scattered light interference. Using optical system such as pinhole or light fiber, the Brownian motion can be observed as the fluctuation of light.

How to measure particle diameter distribution

Particle tracking analysis method

Visualizing and analyzing particles in liquids that relate the rate of Brownian motion to particle size
LM20 / NS500 by NanoSight Ltd

Electrical resistance method

Measuring volume and number of particles from the resistance that rise and fall as particles pass through the aperture.
Multisizer 4 by Beckman Counter, Inc.

Laser diffraction scattering method

Measuring particle diameters from the distribution of scattered light.
SALD-700 (Shimadzu Corporation)

Ultrafine bubble measurement examples

Ultrafine bubble measurement examples

Particle tracking analysis method

NS500 : NanoSight

Laser diffraction scattering method

SALD7100HH : Shimadzu

Resonance mass measurement method

Archimedes : Malvern

Dynamic light scattering method

ELSZ-2plus: Otsuka Electronics
Zetasizer Nano.: Malvern
NANOPHOX: Sympatec

Ultrafine bubble measurement examples

Measuring ultrafine bubbles (3 min. 39 sec.)