# Math Calculation That Ensure The Balancing Machines Calibration

Before doing balancing machine calibration, we assumed that the machine is in compliance, then put standard rotor on the balance machine for calibration (that is to add a standard test mass), after the calibration is completed, if balancing machine displayed value difference is too large, you can think that the balance machine failed.

(A)  The minimum achievable residual unbalance calibration.
1.  Sequence add the test mass at 0&deg;, 30&deg;, 60&deg;, 90&deg;, 120&deg;, 150&deg;, 180&deg;, 210&deg;, 240&deg;, 270&deg;, 300&deg;, 330&deg;of rotor surface. Reading and record the number to a table.
2.  Sum up all the numbers and divide it by 12 and calculate the arithmetic level of each plane. The average recorded in the table "average" column, such as Table 1 shows. Then divide each reading by the average of its corresponding planes and record the results in the "average multiple" column.
3.  The resulting value is plotted as a graph, as shown in Figure 2.
The horizontal lines in the graph represent the arithmetic mean of each plane reading. Two dashed lines (0.88 and 1.12) characterize the average of each plane count has a limitation of &plusmn; 12%.

(B) The unbalance reduction rate calibration
1. put test mass at 0&deg;in the twelve "N" holes of the left test plane and 90&deg;On the right.
2. Doing the test. In each test, left move the mass to 30&deg;,60&deg;, 90&deg;, 120&deg;, 150&deg;, 180&deg;, 210&deg;, 240&deg;, 270&deg;,
300&deg;, 330&deg;. At the same time, move the mass to 60&deg;, 30&deg;, 0&deg;, 330&deg;, 300&deg;, 270&deg;, 240&deg;, 210&deg;, 180&deg;, 150&deg;,120&deg;at right. Each time you try to record data once. Draw the reading on the chart. All the readings are qualified in the corresponding permissible circle. The results are shown in Figure 3.
3. All the points of the calibration results are falling within 90% of the allowable circle, then the unbalance reduction rate is above 90%.

If the he minimum achievable residual unbalance and the unbalance reduction rate both pass the critical calibration, the balancing machine is qualified.