PM51A - Amprobe Pocket Autoranging Digital Multimeter

The Amprobe PM51A is a shirt-pocket-sized autoranging digital multimeter that packs full functionality into a form factor just 10 mm thick and under 85 g. It measures AC/DC voltage to 600 V, resistance to 40 MΩ, capacitance to 3,000 µF, and frequency to 1 MHz — plus continuity with beeper and diode test.

Fully autoranging with seven measurement functions across 27 ranges, the PM51A features an oversized display with large digits. Despite its compact size, it carries full safety ratings of CAT III 300 V and CAT II 600 V (UL approved).

Key Features

• Ultra-Compact – Pocket-sized, ~10 mm thick, under 85 g
• Full Autoranging – 7 functions, 27 ranges
• DC Voltage – 400 mV to 600 V (1–2.5% accuracy)
• AC Voltage – 4 V to 600 V, 50–500 Hz (2–3.5% accuracy)
• Resistance – 400 Ω to 40 MΩ (1–2.5% accuracy)
• Capacitance – 500 nF to 3,000 µF (~3.5% accuracy)
• Frequency – 400 Hz to 1 MHz (~0.5% accuracy)
• Diode Test – 0.25 mA test current, 1.6 V open circuit
• Continuity – Audible beeper, 65 Ω ± 55 Ω threshold
• Safety Rated – CAT III 300 V, CAT II 600 V, UL approved

Detailed Specifications

• DC Voltage:
  • 400 mV (~1% accuracy), 4/40/400 V (~2%), 600 V (~2.5%)
  • Input impedance: 10 MΩ, 30 pF (1,000 MΩ on 400 mV range)
  • NMRR: >50 dB @ 50/60 Hz
• AC Voltage:
  • 4/40/400 V: ~2% (50–60 Hz), ~3% (60–500 Hz)
  • 600 V: ~3.5% (50–500 Hz)
  • Input impedance: 10 MΩ, 30 pF
• Resistance: 400 Ω (~1.5%), 4/40/400 kΩ (~1%), 4 MΩ (~1.5%), 40 MΩ (~2.5%)
• Capacitance: 500 nF, 5/50/500 µF, 3,000 µF (~3.5%)
• Frequency: 400 Hz, 4/40/400 kHz, 1 MHz (~0.5%)
• Sensitivity (V-Peak): >1.3 Vp (5 Hz–100 kHz), >2.2 Vp (100–500 kHz), >4.2 Vp (500 kHz–1 MHz)

Package Contents

• 1× Amprobe PM51A digital multimeter
• 1× Battery (included)