IEC 62037-1:2021 is available as IEC 62037-1:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 62037-1:2021 deals with the general requirements and measuring methods for intermodulation (IM) level measurement of passive RF and microwave components, which can be caused by the presence of two or more transmitting signals. The test procedures given in this document give the general requirements and measurement methods required to characterize the level of unwanted IM signals using two transmitting signals. The IEC 62037 series addresses the measurement of PIM, but does not cover the long-term reliability of a product with reference to its performance. This second edition cancels and replaces the first edition published in 2012. This edition includes the following significant technical changes with respect to the previous edition:
a. clarification added that test equipment may utilize pulsed generators to reduce power consumption;
b. heating effect differences in the device under test noted in Annex B for tests conducted using pulsed generators;
c. guidance added in Annex B to improve probability of detection of short duration PIM events while dynamic testing.