Voltcraft vc 330 ac dc true rms digital current clamp meter voltcraft vc 330 p the voltcraft vc 330 is an ac dc true rms digital current clamp meter that combines ergonomic technology and very good value for money the semi professional clamp meter enables contactless measuring and displays electrical parameters in the range of the overvoltage categories cat ii 600v and cat iii it is able to measure dc and ac voltages to a maximum of 600v direct and alternating currents to a maximum of 1