Rishabh Insulation Tester Rish Insu 10Dx+ is a Digital Insulation Tester with selectable test voltage upto 10kV and Insulation Resistance measurement upto 20 TΩ. Ideal for testing insulation in live switchyards. It comes with a facility to measure PI, DAR, DD and conduct Step Voltage, Ramp test, Burn/Breakdown test automatically.