Greetings all! I am using a Micsig DP10013 probe to measure the signal voltage across the primary of the audio output transformer in a push-pull tube amplifier. The probe's maximum ratings are 1300v (DC+ACp-p) in differential mode. Common mode maximum is either 1000V(DC+ACpeak) CATIII according to the Micsig web site or 1300V (DC+ACp-p) according to the manual. Maximum input signal to earth voltage is 1000V CATII.
For my application the common mode voltage is 540v DC, which is the supply voltage on the plates of the output tubes. The differntial ac signal voltage is 1200V p-p. This would result in a maximum peak voltage of 1140V from each probe tip to earth. I would like to know whether the max signal to earth rating for the DP10013 is 1000V RMS, 1000V DC+ACp-p or 1300V (DC+ACp-p).
Thanks for your input.