Ultra-Precision & Reference Resistors
Tolerances to ±0.005% · TCR to 0±1 ppm/°C · Stability ±0.001%/year. Wire wound components approaching secondary measurement standard performance.
Performance approaching secondary measurement standards.
PRC’s ultra-precision resistors deliver the stability and accuracy demanded by calibration laboratories, metrology systems, precision test equipment, and reference-grade instrumentation. With tolerances as tight as ±0.005%, TCRs as low as 0±1 ppm/°C, and long-term stability of ±0.001%/year, these wire wound components offer performance characteristics approaching those of secondary measurement standards.
The HR, HVA, and RX series share a common design philosophy: epoxy-encased enclosed shell construction, artificially aged resistance wire, and pure copper terminals, optimized for minimal drift and maximum repeatability. These are the components engineers specify when a general-purpose resistor’s stability and accuracy are insufficient for the application.
Ultra-Precision Series
Each series shares PRC’s proven enclosed shell construction with artificially aged resistance wire and pure copper terminals.
HR Series
Axial Lead Ultra-Precision Resistors
- Tolerances from ±0.01% down to ±0.005%
- Standard TCR: 0±5 ppm/°C (special to 0±1 ppm/°C)
- Resistance: 0.1Ω to 10MΩ
- Ideal for DMM calibration, bridge circuits, voltage dividers
HVA Series
- Tolerances to ±0.005%, TCR to 0±1 ppm/°C
- Rectangular body for low-profile mounting
- Resistance: 0.1Ω to 10MΩ
- Higher packing density on PCBs
RX Series
- Radial lead for direct PCB integration
- No overhang of axial lead packages
- Same tolerance, TCR, and stability as HR/HVA
- Perfect for precision instrumentation on-board
DMM Calibrator
- Matched to specific DMM calibration requirements
- Leading calibration protocol compliance
- Custom resistance values available
- Contact PRC engineering for your application
Series Comparison
Compare key specifications across all precision power resistor series to find the right fit for your application.
| Specification | HR Series | HVA Series | RX Series |
|---|---|---|---|
| Form Factor | Axial lead, round body | Axial lead, rectangular body | Printed circuit / radial lead |
| Resistance Range | 0.1Ω to 10MΩ | 0.1Ω to 10MΩ | 0.1Ω to 10MΩ |
| Tolerance | ±1% to ±0.005% | ±1% to ±0.005% | ±1% to ±0.005% |
| TCR (Standard) | 0±5 ppm/°C | 0±5 ppm/°C | 0±5 ppm/°C |
| TCR (Special) | To 0±1 ppm/°C | To 0±1 ppm/°C | To 0±1 ppm/°C |
| Stability | ±0.001%/year @ 25°C | ±0.001%/year @ 25°C | ±0.001%/year @ 25°C |
| Temp. Range | -65°C to +125°C | -65°C to +125°C | -65°C to +125°C |
| Best For | General ultra-precision; widest size selection | Space-constrained high-precision; low-profile | PCB-mount precision; direct board integration |
Need a Custom Solution?
PRC engineers can help you select the right resistor for your precision application — from calibration labs to reference-grade instrumentation.