Introduction
The RD-31 is a versatile three-phase reference standard with a typical accuracy of ±0.01% at power factor (PF) of 1, and a worst-case accuracy of ±0.02% at PF ≥ 0.5. It is designed to accurately measure real-world waveforms using a unique analog to digital signal converter and electronically compensated input transformers.

Characteristics
The RD-31 includes a Harmonic Analysis option for analyzing loads up to the 64th harmonic order and a built-in Comparator for automatic test result calculations. It can test revenue meters and reference standards using a controlled current source and perform three-phase meter accuracy tests in field applications.

Technical Data

• Current Range: 3 × 1mA to 120 (200)A, auto-ranging
• Voltage Range: 3 x 30 to 630V at 60Hz, 3 x 30 to 525V at 50Hz, auto-ranging
• Auxiliary Power Range: 3 × 60 to 630V, auto-ranging
• Frequency: 40 to 70Hz
• Power Factor Range: Any
• Operating Temperature: -20°C to +70°C
• Humidity: 0 to 95%, non-condensing

Measurement Modes
The RD-31 supports various measurement modes including 2-wire active/reactive, 3-wire active/reactive, and 4-wire active/reactive modes, among others.

Accuracy and Drift

• Power/Energy Accuracy: Typical ±0.01% at PF=1, Worst Case ±0.02% at PF≥0.5
• Current Accuracy: ±0.014%
• Voltage Accuracy: ±0.01%
• Long Term Drift: Power/Energy: ±0.0028% first year, ±0.0062% first five years, ±0.0088% first ten years; Current: ±0.0021% first year; Voltage: ±0.0014% first year
• Angle Accuracy: ±0.006°
• Temperature Drift: None between +20°C and +30°C, ±0.0005%/°C outside this range

Additional Features
The RD-31 offers optional features such as a built-in comparator and harmonic analysis. For further technical details, contact the sales department at [email protected].