• Hall effect probe measuring both AC and DC current
• Single range: 0.5 to 1000 Aac and up to 1400 Adc
• Output 1 mV/A; accuracy 2.5 percent or better at 800 A; phase shift 1.5 degrees or less at 800 A, 50 Hz
• Bandwidth DC to 30 kHz (-3 dB, depending on current value)
• Automatic DC zero on both ranges; internal temperature compensation
• Jaw for cables up to 1.5 in (39 mm) or two 1 in (25.4 mm), plus bus bar openings
• Power: 9 V alkaline battery (about 50 hours typical) or 5 V micro-USB Type B; low battery and overload LEDs
• 5 ft (1.5 m) lead with 4 mm safety banana plugs; 600 V CAT III

• High-current AC and DC measurement on feeders, switchgear, and bus bars
• DC power systems, battery banks, and charging infrastructure
• Variable speed drives and power electronics
• Power and energy logging where both AC and DC currents are present, up to 600 V CAT III

• Type: AC/DC current probe, Hall effect, single range
• Current range: 0.5 to 1000 Aac; up to 1400 Adc
• Output signal: 1 mV/A
• Accuracy (50/60 Hz): 2.5 percent or better at 800 A
• Phase shift (50 Hz): 1.5 degrees or less at 800 A
• Frequency range: DC to 30 kHz (-3 dB), depending on current value
• Load impedance: above 1 megohm and 100 pF or less
• Overload: 3000 Adc or 1000 Aac continuous below 1 kHz
• Zero adjust: automatic on both ranges
• Power supply: 9 V alkaline battery (NEDA 1060A, 6LR61) or 5 V DC micro-USB Type B
• Battery life: 50 hours typical; low battery green LED, overload red LED
• Output termination: 5 ft (1.5 m) lead with two 4 mm safety banana plugs
• Maximum conductor size: cables one 1.5 in (39 mm) or two 1 in (25.4 mm); bus bar one 1.97 x 0.49 in (50 x 12.5 mm), two 0.98 x 0.2 in (25 x 5 mm) or 1.24 x 0.30 in (31.5 x 10 mm), or three 0.98 x 0.31 in (25 x 8 mm)
• Dimensions: 9.31 x 3.82 x 1.73 in (236.5 x 97 x 44 mm); weight with battery: 1.15 lb (520 g)
• Operating temperature: 14 to 131 F (-10 to 55 C); storage: -40 to 176 F (-40 to 80 C)
• Relative humidity: up to 85 percent at 35 C
• Safety: IEC 61010-1, EN 61010-2-32, Pollution Degree 2, 600 V CAT III; IP40; EMC EN 61326-1
• Status: active, replaces MR520 (confirmed June 2026); AEMC list reference $329.00; AV-TEK selling price to be set
• Replaces: Model MR520 (Cat. #1200.71)

The AEMC MR525 is a high-current Hall effect probe that measures both AC and DC, which a transformer-type probe cannot do. Clamp it around a cable or bus bar and it outputs 1 mV per amp to a DMM, data logger, or power analyzer, covering 0.5 to 1000 Aac and up to 1400 Adc in a single range. Bandwidth runs from DC to 30 kHz (-3 dB, depending on current value), so it tracks DC levels and AC content together. Accuracy is 2.5 percent or better at 800 A, with a phase shift of 1.5 degrees or less at 800 A and 50 Hz.

Field-ready details: automatic DC zero on both ranges, internal temperature compensation, a 5 ft lead with 4 mm safety banana plugs, and power from a 9 V battery (about 50 hours typical) or a 5 V micro-USB source. Its jaw takes cables up to 1.5 in (39 mm) or bus bars, which is what makes it suited to high-current feeders and switchgear.

The MR525 fits DC and AC current work in drives, DC power and battery systems, and high-current distribution. It replaces the discontinued Model MR520.