... Voltage Tester 1,Small volume, light weight, easily to operate. 2,Unlike DC test, 0.1HZ Digital Very-low-Frequency ... ultra-low frequency source.Advantage of 0.1Hz SVLF series1,Small volume, light weight, easily to operate. Theoretically speaking, ... to dielectric during the testing.Features of function1. Adopting digital convention technology and microcomputers controlling system make the testing ...