Amplitude and speed about shaking incubator

Views: 14     Author: Site Editor     Publish Time: 2020-07-01      Origin: Site

Pay Attention to the Orbit Diameter of shaking incubator:

Inexperienced buyers of shaking incubators often neglect to take into account orbit diameter when selecting an instrument, not realizing how important it is. The orbit diameter of an instrument determines what applications and vessels it is more suitable for.

As a rule of thumb, consider the following when determining which orbit is right for you:

  1. 3 mm (about 1/8"): Best for microplates, microcentrifuge tubes, and other very small vessels.

  2. 15 mm - 25 mm (about 1/2" - 1"): Best for cell culture dishes, and flasks and beakers up to about 2 liters.

  3. 30+ mm: Best for large vessels above 2 liters or especially wide vessels.

What if your vessel is on the cusp? 

For instance, say you want to shake 50 ml centrifuge tubes in a vertical position? The good thing about orbital shakers is that many vessels aren't overly sensitive to the orbit diameter. In the case of 50 ml tubes, you could use a shaker with a 3 mm diameter or an ~20 mm diameter.

That said, for applications that aren't simple mixing, such as cell culture, things get a little more complicated and involve things like aeration. Let's say you have a protocol that says you should shake at 25 mm but your orbital shaker has a 15 mm diameter. What can you do?

You can usually compensate for a somewhat different orbit diameter (say, +/- 50% of what a protocol calls for) by changing the speed. If your orbit diameter is smaller than what your protocol calls for, simply turn up the RPM a bit to compensate. Conversely, if the orbit diameter was too large you would decrease the speed somewhat.

So don't worry about orbit diameter - it doesn't need to be perfect - but do be aware of orbit diameter, as it's more important than a lot of people realize.


Zhichu provides shaking incubator with amplitudes of Ø1.5mm, Ø3mm, Ø26mm, and Ø50mm.


Correlation between amplitude and speed of shaking incubator:

The centrifugal force in the shake flask can be calculated by the following formula:  FC=rpm2 × amplitude

There is a linear relationship between centrifugal force and amplitude: 

If use Ø25mm to Ø50mm (same speed), the centrifugal force is increased by 2 times.


There is a square relationship between centrifugal force and speed:

If the speed is increased to 2 times (same amplitude), the centrifugal force is increased by 4 times. If the speed is increased to 3 times, the centrifugal force is increased by 9 times!

If using Ø25mm, incubate at a given speed. If you want to use Ø50mm to achieve the same centrifugal force, the rotation speed should be calculated as the square root of 1/2, so you should use 70% rotation speed to achieve the same cultivation conditions.


Please note that the above is just a theoretical method of calculating centrifugal force. There will be other influencing factors in real applications. This calculation method can get approximate values for operation reference.

(Disclaimer: The article comes from the Internet, only for learning and communication, please contact us to delete if infringement is involved. For specific use of Zhichu shaking incubator, please follow the product manual or consult Zhichu engineers)

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