Naturally any water that comes out of a pressurized water supply will contain dissolved gases and these gases need to be removed or degassed from the solution for maximum ultrasonic cleaning performance.  The reason for removal is gases are easier to compress than liquids; therefore, when the ultrasonics cavitate the solution, some of the cavitation energy is absorbed by the gases.  

Degassing solution is easily achieved by either letting the solution sit out for number of hours.  This is why a glass of water tastes “different” when first out of the faucet vs. drinking it hours later.   Running the ultrasonics in a tank will expedite the degas process significantly typically down to 5-10 minutes.  Keep in mind solution only needs to be degassed when first dispensed from a pressurized supply.

Although 5-10 minutes is much shorter than hours achieved by letting the solution sit, 5-10 minutes is still too long to wait for our automated cleaning and passivation systems to degas each time the solution is pumped from the storage tank to the process tank.  Our system feature a fast-degas feature at the start of the ultrasonic cycle which allows the solution to degas in a matter of seconds vs. minutes.

The fast degas feature can be heard in the video below (note high pitch of ultrasonic degas and tuning amplified for video demonstration)

How to tell if a solution is degassed or not?

Solution de-gases by simply releasing the dissolved and entrapped air in solution.  During a degas process with ultrasonics,  fine bubbles will suddenly appear and begin to rise to the surface of solution (similar to that seen after first pouring a glass of beer) This implosion or cavitation of solution with dissolved gases can result in high pitched audible sound from the ultrasonic tank until the solution is degassed as heard in the video above.

Once a solution or fluid is degassed either by letting it sit, ultrasonic cavitation energy, or heating, it does not need to be degassed again unless the solution replaced with new fluid.