Active Current Shunt

Model 2575A

2575A Active Current Shunt Front View
2575A Active Current Shunt Back View
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  • Precision AC-DC Active Current Shunt
  • AC & DC Current Measurement to 100 Amps
  • Built-In Chopper Stabilizer Amplifier
  • Measurement tool for AC and DC
  • Working Calibration Standard
  • Calibration Traceable to NIST
  • Six Independent Switch Selectable Current Ranges
  • Fan-cooled Shunts for Thermal stability
  • Low Resistance Lab Standard Resistance Bank


  • HC: 2555A to 2575A 100A Cable Set
  • RX-3: 19″ Rack Mount Adapter Kit
  • BBL:  Banana-to-Banana Cable Set
  • M2575:  Additional User / Maintenance Manual

A versatile, powerful calibration tool.

The 2575A Precision AC-DC Active Current Shunt measures both AC/DC current and works as a standard for low-level resistance calibration requirements. 

What’s New?

Built-in precision gain 10  chopper stabilizer buffer amplifier.

What’s Wrong With Using DC Resistors to Certify AC Current?

Plenty! To start with most lab standard resistors are designed to permit close trimming to a nominal DC value. These DC resistors contain inductive components, which even though very small, can result in significant AC voltage error (especially in the lower resistance values). To this end, each range of the 2575A utilizes a specially designed non-inductive resistance element which insures a flat frequency response to 10KHz.

AC & DC Current Measurement to 100 Amps

In the current measurement mode, the 2575A offers six independent switch selectable ranges from 1 milliamp full scale to 100 amperes. All but the maximum range feature 100% overrange capability. The 100A, 10A and 1A range shunt resistors are fan cooled to insure minimum heat rise and thereby maximize thermal stability (<0.001% per°C).

Four-Terminal Performance You Can Bank On

When used as a lab standard resistance bank, the 2575A provides six decade values of 4-terminal resistors from .001 ohm to 100 ohms all ranges independentlhy calibratable. is independently adjustable.

Built-In Chopper Stabilizer Amplifier

The full scale voltage drop across the shunt is 100.00 millivolts at rated current. A precision gain of 10.000 wide-band chopper amplifier is incorporated to provide a higher level output, capable of driving thermal transfer standards. The amplifier is available for use with external inputs and features an input impedance of 10,000 megohms.

Key Specifications

Range Name & Maximum Input Shunt Value DC Accuracy (% of Range) AC Accuracy (% of Range) Frequency Response
100A 0.001Ω ±0.05% ±0.1% DC to 1kHz
20A 0.01Ω ±0.02% ±0.1% [1] DC to 10kHz
2A 0.1Ω ±0.02% ±0.1% DC to 10kHz
200mA ±0.01% ±0.1% DC to 10kHz
20mA 10Ω ±0.01% ±0.1% DC to 10kHz
2mA 100Ω ±0.01% ±0.1% DC to 10kHz
NOTES: [1] AC accuracy is ±0.5% of range above 1kHz

Amplifier Characteristics:

  • Amplitude Gain: 10.000
  • Gain Accuracy: ± 0.01% 10µV RTI @ DC
  • Frequency Response: ± 0.1% to 10 Khz
  • Input Resistance: Greater than 1010Ω
  • Output Resistance: Less than 0.1Ω
  • Temperature Range: 0 to 50°C
  • Temperature Coefficient: Less than .001% per °C
  • Voltage Drop (before amplifier): 100.00 mV for full scale input current
  • Power: 115/230 VAC 50-60 Hz 12 Watts
  • Size: 3.5″H x 17″W x 10″D (8.9cm x 43.2cm x 25cm)
  • Weight: 8 lbs. (3.6KG) Net 13 lbs. (5.9 KG) Shipping