Add isolated inputs to your oscilloscope using passive probes.

Siglent's Isolated channel module (ISFE - https://www.saelig.com/product/M0011018.htm  enables floating ground differential signal analysis.

 
The ISFE provides isolated input capabilities to any oscilloscope. Independently developed by SIGLENT, it is designed to measure signals that do not share earth ground with the oscilloscope. It is suitable for use with SIGLENT’s full range of oscilloscope products. It adopts USB port 5V power supply of the oscilloscope, and its maximum input voltage is up to ± 600Vpp.

Features and Benefits:
● Plug-and-play oscilloscope option
● USB 5 V power supply, power consumption less than 1 W, ease of use
● Single channel isolation voltage 1000 Vrms, channel segregation voltage 2000 Vrms
● Can be used to measure: Household 220 VAC signals, three-phase AC, three phase power, etc.
● Achieve common oscilloscope channel isolation, measured signal and ground isolation

Input voltage range	-600 Vpk ～ +600 Vpk
Voltage attenuation ratio	about 200:1
Bandwidth	≤ 1 MHz
Output voltage range	-3 Vpk ～ +3 Vpk
Working voltage	5 V±5%，USB supplies power
Working current	< 200 mA
max isolated voltage to ground	1000 Vrms
max isolated voltage between channels	2000 Vrms
Input impedance	10 MΩ

DSO (with data recorder) + ISFE (isolated channel option) + PSA (power software analysis) can be used to measure high currents or circuits without ground references.

View the ISFE Users Manual