GPM-001 is a digital multimeter/voltmeter/amperometer manufactured by GW Instek. It has a 3-1/2 digit liquid crystal display with a resolution of 2000 counts and a measurement accuracy of ±0.5%. The multimeter has a wide range of functions, including AC/DC voltage measurements, AC/DC current measurements, resistance measurements, frequency measurements and temperature measurements. It also allows for manual ranging, auto ranging and data hold. In addition, the GPM-001 has diode test, continuity test and buzzer functions.