BS ISO 21940-21:2012

1   Scope This part of ISO 21940 specifies requirements for evaluating the performance of machines for balancing rotating components by the following tests:

       a)  test for minimum achievable residual unbalance,   U   mar  test; 
   
   
     
       b)  test for unbalance reduction ratio, URR test; 
   
   
     
       c)  test for couple unbalance interference on single-plane machines; 
   
   
     
       d)  compensator test. 
   
 

These tests are performed during acceptance of a balancing machine and also later, on a periodic basis, to ensure that the balancing machine is capable of handling the actual balancing tasks. For periodic tests, simplified procedures are specified. Tests for other machine capacities and performance parameters, however, are not contained in this part of ISO 21940. For these tests, three types of specially prepared proving rotors are specified, covering a wide range of applications on horizontal and vertical balancing machines. An annex describes recommended modifications of proving rotors prepared in acccordance with ISO 2953:1985. [2]

Moreover, this part of ISO 21940 also stresses the importance attached to the form in which the balancing machine characteristics are specified by the manufacturer. Adoption of the format specified enables users to compare ...