Analytical Balances

Minus K vibration isolation systems enable analytical balances to operate in vibration environments not previously possible, such as in manufacturing facilities with heavy equipment and on upper floors of buildings.

Analytical balances are particularly sensitive to vibrations because they introduce g-loads that interfere with the basic weight measurement mechanism - the effect of gravity on a mass. Vibrations reduce the resolutions and prevent the balances from achieving their performance capabilities. High-resolution balances with resolutions down to 1 or 0.1 microgram are particularly sensitive to vibrations, even with the built-in electronic averaging techniques used to compensate for vibrations. A reduction of even one decimal place can seriously affect the usefulness of balances for some research studies.

Low-frequency vibrations are particularly difficult to attenuate, such as floor and ground vibrations caused by vehicles or heavy equipment in manufacturing plants. Low-frequency vibrations are also present in upper floors of buildings, particularly horizontal vibrations caused by wind sway and vertical vibrations from footfall or nearby equipment. Consequently, some metrology labs have not been located in manufacturing facilities where they would be most useful, and some laboratories on upper floors of buildings have not been able to use high-resolution balances to their maximum effectiveness.

Traditionally, vibration problems have been solved with “balance tables” made from marble or other heavy material. These balance tables reduce vibrations by adding mass and rigidity, but they have limited effectiveness in high vibration environments. Air tables have been used with limited success because they are not effective against low-frequency vibrations and have limited attenuation of typical ground and building vibrations. Active or electronic force-cancellation systems have also been used but these are very expensive and also have limited dynamic range and cannot handle large amplitude vibrations.

Minus K vibration isolation platforms perform 10-100 times better than air tables, depending on the vibration frequency, and even better than active systems for a fraction of the cost. They have been effective in allowing analytical balances to operate in severe vibration environments and achieve improvements in resolution of not just one, but in some cases, two and three decimal places.