A method of measuring friction, comprising: providing an electromechanical liquid level gauge that uses a servo principle (ESG) including a controller having a processor , a displacer suspended on a measuring wire from a measuring drum for causing a torque on said drum having a servo motor with a gear coupled by moving parts including a drive shaft , and ball bearings associated with said servo motor for rotating said drum arranged to balance a weight of said displacer in a tank , wherein a change in a level of a liquid in said tank causes a change in a counterforce to move said ESG out of balance, a force transducer positioned for measuring said torque on said drum and converting said torque into a physical quantity, wherein said processor includes an associated memory storing a friction determination algorithm executed by said processor implementing: first moving said displacer in a first direction from an initial displacer position for at least one full step of said servo motor to reach at least a first displacer position; obtaining first physical quantity data including at least a first physical quantity (Q1) measured by said force transducer while said displacer is at said first displacer position; second moving said displacer in an opposite direction relative to said first direction for at least one full step of said servo motor to reach at least a second displacer position; obtaining second physical quantity data including at least a second physical quantity (Q2) measured by said force transducer while said displacer is at said second displacer position, characterised by determining a hysteresis measure from said first physical quantity data and said second physical quantity data, the step of determining comprises: generating a curve including a number of parameters of frequency that relates to a plurality of different positions of the servo motor with movement of said displacer in said first direction and said second direction, and determining a condition of said ball bearings from whether said curve shows a sawtooth pattern for upward movement of said displacer. first moving said displacer in a first direction from an initial displacer position for at least one full step of said servo motor to reach at least a first displacer position; obtaining first physical quantity data including at least a first physical quantity (Q1) measured by said force transducer while said displacer is at said first displacer position; second moving said displacer in an opposite direction relative to said first direction for at least one full step of said servo motor to reach at least a second displacer position; obtaining second physical quantity data including at least a second physical quantity (Q2) measured by said force transducer while said displacer is at said second displacer position, characterised by determining a hysteresis measure from said first physical quantity data and said second physical quantity data, the step of determining comprises: generating a curve including a number of parameters of frequency that relates to a plurality of different positions of the servo motor with movement of said displacer in said first direction and said second direction, and determining a condition of said ball bearings from whether said curve shows a sawtooth pattern for upward movement of said displacer. generating a curve including a number of parameters of frequency that relates to a plurality of different positions of the servo motor with movement of said displacer in said first direction and said second direction, and determining a condition of said ball bearings from whether said curve shows a sawtooth pattern for upward movement of said displacer. <EOS>