Vanguard Auto-Ohm 10 Micro-Ohmmeter | 10 A true DC, 0.1 µΩ resolution, ±0.2%, approx. 2,900 tests per Li-ion charge

Vanguard Auto-Ohm 10 Micro-Ohmmeter: 10 A True DC

Overview

The Auto-Ohm 10 is Vanguard's 10 A battery-operated micro-ohmmeter for low-resistance measurement of circuit breaker contacts, bushing connections, welds and similar joints. A rotary knob switches between two modes: "contact resistance" and "transformer resistance". It has four built-in 3.7 V / 3400 mAh Li-ion batteries and a charger; each charge allows approx. 2,900 tests (10 A, 2 seconds), and it can also run continuously on mains power.

Key Specifications

• Test current and range: 10 A: up to 250 mΩ; 5 A: up to 999.99 mΩ; 1 A: up to 5,000 mΩ; 100 mA: up to 50 Ω; 10 mA: up to 500 Ω; 1 mA: up to 5,000 Ω
• Accuracy: ±0.2% ± least significant digit (±0.2 µΩ at 0.1 µΩ resolution on the 10 A range), bidirectional current mode
• Battery: Four 3.7 V, 3400 mAh Li-ion batteries; 4-hour charge; approx. 2,900 tests (10 A / 2 seconds)
• Power: 100–240 Vac, 50/60 Hz
• Display: Backlit LCD (128 × 64), readable in bright sunlight and in the dark
• Protection and environment: Input protection 600 V; operating temperature -10 to 50 ℃
• Dimensions and weight: 36 × 19.4 × 30.4 cm; 3.54 kg

Applications

• Contact resistance measurement of high-voltage circuit breaker contacts and busbar joints.
• Low-resistance testing of transformer windings and welds.

Specifications per the specification table on the Vanguard Auto-Ohm 10 product page (doble.com, retrieved 2026-10-23).