scope:

This International Standard specifies requirements for heat test source (H.T.S.) lamps used for carrying out those thermal tests of IEC 598 primarily check the influence of heat conducted through the lamp cap as well as of convection. For a description of the origin and philosophy of this standard see annex A.

Where H.T.S lamps are not available, an alternative heat test source (A.H.T.S.) lamp may be used.

A guideline of the selection and preparation of such lamps is given in annex B of IEC 598-1.

Some consideration has been given to radiation test sources (R.T.S.) in annex A.