Micro bubbles and Ultra Fine bubbles are generally called Fine Bubbles.

Micro Bubbles are defined as the diameter bigger than 1μｍ and smaller than 100μｍ. 1μｍ is 1/1000 ｍｍ. 。（ISO 20480-1:2017）

Micro bubbles have competence of minus ion which contributes to all kinds of performances link to micro bubbles.

Micro bubbles may be visible but difficult to be seen when they are smaller than 5μｍ.

Nano bubbles are smaller than １µm which are difficult to be identified by bare eyes.

June 2017, ISO defines bubbles with diameter less than 100㎛ as Fine Bubbles, while diameter bigger than 1㎛ as Micro Bubbles, less than 1㎛ as Ultra Fine Bubbles.

Reference sizes to be compared (1 μm and 10 μm):

  • 1–10 μm – length of a typical bacterium
  • 3–8 μm – width of strand of spider web silk
  • about 10 μm – size of a fog or mist

Reference sizes to compare (10 μm and 200 μm):

  • about 10–12 μm – thickness of plastic wrap 
  • 10 to 55 μm – width of wool fiber
  • 17 to 181 μm – diameter of human hair
  • 70 to 180 μm – thickness of paper
  • 200μm– diameter of human pores