North Atlantic 321A

The North Atlantic 321A is a wideband phase angle voltmeter for precise measurement of voltage and phase relationships across a broad frequency spectrum. It measures total voltage, fundamental voltage, and in-phase/quadrature components relative to a reference input, making it essential for amplifier and network design, vibration analysis, telemetry systems, and biomedical research. The instrument employs a phase-locked loop circuit for automatic reference signal acquisition with LED lock indication, and uses proprietary circuit techniques that eliminate reactive phase shifters and filters to deliver superior accuracy and stability.

– Technical Specifications

• Voltage Measurement Range: 300 µV to 300 V RMS
• Voltage Accuracy (Total Mode): ±2% of full scale
• Phase Nulling Sensitivity: 2 µV
• Quadrature Overload Capability: Up to 10× full-scale in-phase voltage
• Phase Angle Range: 0° to 360° (4 quadrants)
• Phase Angle Accuracy: ±0.5° to ±1.5° (frequency-dependent)
• Phase Dial Resolution: 0.5° increments
• Frequency Range: 10 Hz to 100 kHz (four decade ranges)
• Input Impedance: 10 MΩ shunted by 50 pF
• Input DC Voltage: 400 VDC
• Reference Input Variation: 150 mV to 150 V (no calibration required)
• Harmonic Rejection: >40 dB

– Key Features

• Phase-locked loop circuit with automatic reference input acquisition
• Lock indicator LED
• Isolated reference input—floats independent of circuit ground
• Automatic gain control maintains independent reference channel operation
• Proprietary design eliminates phase shifters and reactive filters
• Measures in-phase (0°/180°) and quadrature (90°/270°) voltage components

– Typical Applications

• Amplifier and network characterization
• Vibration analysis systems
• Telemetry signal measurement
• Biomedical research instrumentation

– Compatibility & Integration

Options include extended voltage range (Option 03), communication interfaces such as RS-232 and GPIB (Option 04), and an economy configuration (Option 09) with reduced features.