MI AccuLoss 2500A High-Voltage Divider

The MI AccuLoss® 2500A series from Measurements International offers unmatched precision in measuring and scaling high AC voltages up to 960 kV. Thanks to its innovative design based on a current comparator, this high-voltage divider is ideally suited for applications in energy measurement, calibration, and power analysis.

Technical Description
The 2500A, 2501A, 2502A, and 2503A models constitute the low-voltage arm of a capacitive high-voltage divider. By utilizing a compensated current comparator, the current in a high-voltage capacitor is compared to that in a reference capacitor. A feedback loop automatically corrects the output voltage for dissipation and magnitude errors, resulting in a self-balancing and highly accurate output voltage.

Each unit features seven gain factors (1, 2, 5, 10, 20, 50, 100), allowing the input voltage range to be flexibly adjusted. The output voltage is standardized at 120 V AC, regardless of the input level, with a 10% overrange margin.

Key Features

> Voltage range: 120 kV to 960 kV AC (depending on model and capacitor)
> Output voltage: 120 V AC RMS (with 10% overrange)
> Accuracy: < 20 ppm (both magnitude and phase)
> Frequency range: 40 Hz to 400 Hz
> Calibration interval: 3 to 5 years
> Interface: IEEE-488 for automated control
> Warm-up time: < 5 minutes to full accuracy
> Environment: 10–34 °C, 10–18% relative humidity

Practical Benefits

The MI AccuLoss® 2500A series stands out not only for its technical specifications, but above all for the practical benefits it offers to users in the field and in the laboratory:

Exceptional Accuracy and Stability
Thanks to its design based on a compensated current comparator, the instrument achieves unmatched accuracy, with an uncertainty of less than 20 ppm. Automatic correction of dissipation and phase errors ensures that measurements remain reliable, even in the face of temperature changes or component aging.
> Flexibility in voltage range
With seven built-in gain factors and compatibility with various input capacitors, a single instrument can measure a wide range of voltages—from a few hundred volts to nearly one million volts. This makes the system scalable and future-proof.
> Rapid Deployment
With a warm-up time of less than five minutes, the system is quickly operational, saving time during routine measurements or calibrations.
> Automated and manual operation
The 2500A can be controlled via both the front panel and the IEEE-488 interface. This makes it possible to integrate the system into automated test setups or operate it manually for ad hoc measurements.
> No recalibration required between measurements
Thanks to its self-balancing operation and high stability, there is no need to constantly readjust or recalibrate the system. This increases reliability and reduces maintenance costs.

With its relatively small size and a weight of 18 kg, the 2500A is easy to move and integrate into existing measurement setups without compromising performance or safety.

Application

The MI AccuLoss® 2500A series is designed for demanding applications in high-voltage metrology and power analysis. Thanks to its high accuracy, stability, and versatility, this high-voltage divider can be used in a wide range of environments, from calibration laboratories to power plants. Some typical applications include:

1. Loss Measurements on Transformers and Reactors
   The 2500A can be integrated into loss measurement systems to determine the efficiency of transformers and inductive components. When used in combination with a power analyzer such as the MI 2020A, it enables accurate measurements of active and reactive losses at high voltages.
2. Calibration of Standard Voltage and Resistance Dividers
   Thanks to its high linearity and low uncertainty, the 2500A is ideal for calibrating other voltage dividers or standard measuring transformers. This makes the instrument suitable for national metrology institutes and calibration laboratories.
3. AC High-Voltage Measurement Systems
   The dividers can be used for the reliable measurement of AC high voltages in test setups, validation environments, or production processes where accurate voltage verification is required.
4. Power Calibration Systems
   In combination with reference capacitors and precision instrumentation, the 2500A can be used to calibrate power meters and energy measurement instruments, both in the laboratory and in the field.
5. Precision Current-to-Voltage Conversion
   Thanks to its current comparator technology, the system can also function as a highly accurate current-to-voltage converter, for example, in combination with standard AC resistors.
6. Research and Development
   For R&D departments in the energy sector, the 2500A provides a reliable measurement platform for developing and testing new high-voltage components and systems.

Model Overview and Compatibility

For more information and other available capacitor values, please contact one of our consultants.