HP power sensor question
 

Hi all,
I have two HP power sensors: a HP 8481A and a HP8485A. After extensive
calibration etc I learned that they differ about 0.4 dB at 12 GHz. No real
difference (0.03 dB) on 500 MHz. Is that due to vswr alone or is one of the
sensors maybe damaged? I use a HP 435B and a HP 438A. Please advise.
Regards,
Harke PA0HRK