This standard ( Part 1 ) specifies the characteristics and dimensional requirements of high-power X-ray tubes with rotating anode, Type DRA-1, with two foci, each focus having the same target angle.
IS 10961 Pt.1-1988 history
1989IS 10961 Pt.1-1988 Specification for diagnostic X-ray tubes with rotating anodes Part 1 Type DRA-1