Does isolation help to solve my test gear noise issue?

Clearly yes! Measurement gear like PicoScope is usually not isolated. The input ground of the device is connected to the USB ground.

Now, if both your host PC and your DUT are connected to PE, you very likely run into a ground loop that will mess up your results.

Even if you don't have ground loop issues, your noise will go down 1-2 dB.

Our 7055-B (USB 2.0 only) and 7055-D (USB 2.0+3.0) models work with all kind of oscilloscopes and spectrum analyzers. Please note that we explicitly do not recommend our model 7055-C in this context. Further, for Picoscope Series 5, we recommend 7055-E.

But be aware that these devices are power hungry. You will need to connect an external power supply to the AUX port of the isolator. Any mobile phone charger should do. The scopes are usually designed to deal with potential ripple coming from the charger.

We have tested following products intensively (as we are using them in our daily lab work):

PicoScope 2000 (tested: 2205A, 2406B)
PicoScope 3000 (tested: 3204D MSO)
PicoScope 4000 (tested: 4444, 4262)
PicoScope 5000 (tested: 5443D with Intona 7055-E)
SignalHound BB60C
PrismSound dScope III
All sorts of FTDI-based UART/JTAG/SPI/I2C adapters