The FUNDAMIX® is a well established mixing technology for products which require mixing at low shear forces, which is typically the case in the biotech environment. While cGMP practices intend to control production processes to guarantee quality of products, it means that the mixing quality of an agitated vessel needs to be monitored to assure compliance.
Vibratory action on a mixing plate produces a vertical flow of the fluid. The displacement volume is basically a function of frequency x amplitude. When the drive unit is connected straight to the power supply the oscillating frequency is equal to twice the grid frequency, i.e. either 2x50Hz = 100Hz or 2x60Hz = 120Hz. In case a frequency converter is applied its frequency can be monitored on the device and is a fixed value.
For the amplitude, however, it is a different issue. It depends on many other influencing factors, such as weight of mixing device, fluid density and viscosity or size and shape of mixing plate. This leaves no other option but measure the actual physical displacement of the plate.