HPS Series High Power Precision Shunt Resistors

What are the HPS Series High Power Precision Shunt Resistors?

The HPS is a high-power precision shunt resistor designed for accurate current measurement at continuous currents up to 387A and sustained dissipation levels up to 250W. It combines the very tight tolerance and low temperature coefficient of resistance associated with laboratory-grade current sensing components with a robust copper-flanged body capable of direct heatsink mounting, bridging the gap between the precision achievable in bench instrumentation and the power-handling capacity required in industrial and energy test environments. The copper flange provides an efficient thermal path from the resistive element to an external heatsink, enabling continuous high-current operation provided that terminal and flange temperatures are maintained at or below 60°C through adequate heatsinking and forced-air cooling where necessary.

The resistance range of 1mΩ to 100mΩ covers the sub-milliohm and low-milliohm values demanded by high-current sensing circuits, where minimising the voltage burden across the shunt is essential to avoid disturbing the circuit under test. Four tolerance grades are available: ±0.05%, ±0.1%, ±0.5%, and ±1%, allowing selection of the accuracy level appropriate to the measurement system. TCR options of 3, 5, and 10 ppm/°C represent among the lowest available for a shunt resistor of this power class, ensuring that the resistance value remains stable across the temperature excursions inherent in high-power operation. The tightest TCR grade of 3 ppm/°C, combined with the ±0.05% tolerance, makes the HPS suitable for applications where measurement uncertainty must be maintained at the lowest possible level even as the component operates at elevated temperature.

Stability under sustained load is a defining characteristic of the HPS. Short-term stability is specified as the change in resistance after one hour of continuous operation at rated current, with values of ≤±0.02%, ≤±0.03%, ≤±0.05%, or ≤±0.1% depending on the tolerance grade, confirming that the component does not drift significantly during a measurement session. Long-term stability of ≤±0.2% after 1,000 hours of operation under rated conditions provides confidence in calibration intervals appropriate for test and measurement equipment and reference standards. These stability figures, combined with the dielectric withstanding voltage rating of AC 500V, confirm the HPS as a component designed for the demanding accuracy and reliability requirements of precision laboratory and industrial power measurement systems.

Model: HPS
Resistor type: Current sensing
Description: High power precision
Power Rating: 250W
Rated Current: 387A max.
Resistance (Ω): 1m~100m
Tolerance (%): ±0.05, ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10

Model: PSS
Resistor type: Current sensing
Description: High power precision
Power Rating: 100W
Rated Current: 1400A max.
Resistance (Ω): 50u~1m
Tolerance (%): ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10

Model: IRHF
Resistor type: Current sensing
Description: High power precision
Rated Current: 30A~500A
Resistance (Ω): 0.2m~3.333m
Tolerance (%): ±0.1, ±0.5, ±1
TCR (ppm/C): 15, 30

Model: LT
Resistor type: Current sensing
Description: High power precision
Rated Current: 50A~500A
Resistance (Ω): 0.2m~2m
Tolerance (%): ±0.1, ±0.5, ±1
TCR (ppm/C): 30

Model: UHPS
Resistor type: Current sensing
Description: Ultra high power precision
Power Rating: 100W
Rated Current: 707A max.
Resistance (Ω): 0.2m~1m
Tolerance (%): ±0.05, ±0.1, ±0.5, ±1
TCR (ppm/C): 3, 5, 10