Volcraft dvm digital panel meters voltmeter modules voltcraft dvm230rn the volcraft dvm 230rn dc digital voltmeter module is a panel meter for installation in power supplies lab equipment control panels etc din dimension 48 x 24mm and 10mm digit height includes a led backlight for dark conditions with an additional current consumption of about 50ma virtually any measuring range may be achieved by simply adding resistors voltage divider shunt example electrical connection via sol