Test pen with AC and DC voltage measurement (includes three-phase alternating current (AC) measurements, three-phase AC phase indicator, on, single pen measurement can be the zero line and the Firewire) Phase rotation test: operating voltage 100V ~ 690V, frequency 50Hz ~ 60Hz Single wire voltage detection (L2) Operating voltage voltage: 100V ~ 690V, frequency: 50Hz ~ 400Hz Continuity test: 0 ~ 100k resistance, beeper and LED indicator RCD test Operating voltage: 230V (50Hz ~ 400Hz) Can be applied to: smelting, electronics, manufacturing, petroleum, national defense, power, chemical and other industries. Also used to solve complex problems in electronics, industrial automation, power distribution, and mechanical and electrical equipment. features< /p> Waterproof (IP65): Low battery indicator: two wire short circuit, LED and beep when battery is low low. LCD display (voltage + frequency): 6V ~ 690V (40Hz ~ 400Hz) Over voltage: range of voltage 713V ~ 788V Auto standby: standby current &lt; 10uA Low battery indicator: voltage range: 2.2V ~ 2.4V. use It can be applied: foundry, electronics, manufacturing, petroleum, national defense, energy, chemical and other industries. It is also used to solve complex problems in electronics, industrial automation, power distribution, and mechanical and electrical equipment.