Abstract: To ensure high-precision calibration of gear measuring instruments

the international standard ISO / TR 10064-5:2005 recommends a Double-Ball Artifact (DBA) as calibration reference. The DBA employs a high-precision sphere instead of the involute

by means of error compensation technique

to reach high-precision involute for traceability. The theoretical issues relating to the DBA are discussed in this paper to supply theoretical basis of the design and application of DBA. The error of measurement principle of DBA and its calculation function are given under the conditions of ideal installation and being installed with error for the electronic generative metrology; according to the optimized arc thoughts

the formula of optimized center distance of two ball is derived by the least square method; finally

this paper describes the error compensation method. The DBA software was designed based on the above theory and a DBA was developed with parameters of module 2.2681mm

number of teeth 40

and pressure angle 20 °.