MI 9332 Precision High Current Shunts

Standard DC current shunts for precision applications up to 3000 amps

The 9332 Series from Measurements International is engineered for ultra-precise DC current measurements up to 3000 A. These four-terminal standard shunts combine years of materials research with advanced thermal and electrical optimization. The result is a robust, air-cooled current shunt with exceptionally low temperature coefficients, minimal self-heating, and long-term stability that meets the highest standards of calibration laboratories and industrial measurement setups.

Construction and Thermal Design

Each shunt is built from carefully selected resistive elements soldered to copper terminations using a specialized low-thermal solder. These elements undergo a controlled annealing process that minimizes internal stress and optimizes the temperature coefficient. The copper ends are designed to distribute current evenly across the element, ensuring stable power dissipation in air.

The housing features a perforated protective cover that allows free airflow while shielding the element from physical damage. This design enables full-power operation without external cooling. For applications requiring enhanced thermal control, an optional forced-air cooling module (9332-FAN) is available. This module mounts directly to the shunt guard and reduces the power coefficient at high current levels.

Electrical Performance and Calibration

The 9332 Series offers exceptionally low measurement uncertainty, with typical accuracy better than 0.01% at full power. Temperature coefficients are below 3 μΩ/Ω/°C for most models, and one-year stability remains within 10 μΩ/Ω for standard values. Each unit is supplied with a calibration report detailing resistance and uncertainty at 10% and 75% of nominal current.

All shunts include an integrated temperature sensor, allowing users to model resistance variation as a function of temperature. This makes the 9332 Series suitable not only as a current shunt but also as a standard resistor in air or in a temperature-controlled air bath such as the MI 9300A.

Models overview Measurements International 9332-series

Applications

The 9332 Series is ideal for use in calibration laboratories, national metrology institutes, and industrial environments where precise current measurement and standardization are required. Thanks to its low uncertainty and high stability, these shunts are suitable as primary standards or transfer standards in interlaboratory comparisons.