Extech EX330 digitalmultimeter, 4000 counts, CAT III 600V, True RMS, auto-ranging

Electricians, HVAC technicians, and electronics hobbyists use the Extech EX330 on service calls and bench work to measure voltage, current, resistance, capacitance, frequency, and temperature. This compact auto-ranging multimeter fits in one hand and delivers True RMS accuracy for reliable readings on both linear and non-linear loads.

Key specifications

• Display: 4000 counts with backlight
• Safety rating: CAT III 600V
• True RMS: Yes
• Auto-ranging: Yes
• DC voltage: 0.1 mV to 600 V
• AC voltage: 0.1 mV to 600 V
• DC current: 0.1 µA to 10 A
• AC current: 0.1 µA to 10 A
• Resistance: 0.1 Ω to 40 MΩ
• Capacitance: 0.01 nF to 100 µF
• Frequency: 0.001 Hz to 10 MHz
• Temperature (Type K): -20 to 750°C (-4 to 1400°F)
• Diode test: Yes
• Continuity test: Yes (audible beeper)
• Data hold: Yes
• Min/Max function: Yes
• Auto power off: Yes
• Power source: 2 x AAA batteries
• Calibration: Factory standard (without certificate)

Why choose it

The EX330 combines essential measurement functions with True RMS accuracy and a backlit display, making it suitable for troubleshooting in dimly lit panels or tight spaces. Its auto-ranging feature reduces setup time, and the Min/Max function helps capture signal fluctuations.

Ideal use cases

• Electrical installation and maintenance
• HVAC system diagnostics
• Appliance repair
• Electronics testing and hobby projects

Good to know

The meter is calibrated to factory standards without a certificate. It operates on two AAA batteries and includes auto power off to conserve battery life.