The Stanford Research SR810 DSP Lock-In Amplifier is a precision instrument designed to extract minute AC signals from noisy environments using advanced digital signal processing. Unlike traditional analog lock-in amplifiers, the SR810 eliminates input tracking band-pass filters, avoiding associated noise, amplitude, phase errors, and drift. Its >100 dB dynamic reserve enables drift-free measurements across optics, materials science, and advanced electronics applications.
Technical Specifications
Signal Channel
• Input: Single-ended (A) or differential (A-B) voltage; current inputs available
• Sensitivity: 2 nV to 1 V full-scale, adjustable in 1-2-5-10 sequence
• Current Input Gain: 10⁶ V/A or 10⁸ V/A
• Input Impedance: 10 MΩ ± 25 pF (voltage inputs), AC or DC coupled
• Input Noise: 6 nV/√Hz at 1 kHz (voltage); 0.13 pA/√Hz at 1 kHz or 0.013 pA/√Hz at 100 Hz (current, gain-dependent)
• Line Filters: Switchable 50 Hz or 60 Hz; 2× line filters at 100 Hz or 120 Hz
Reference Channel
• Frequency Range: 1 mHz to 102.4 kHz
• Frequency Accuracy: 25 ppm + 30 µHz
• Frequency Resolution: 4½ digits or 0.1 mHz
• Phase Resolution: 0.01 degrees
• Harmonic Detection: Capable of measuring any harmonic (2F, 3F, … nF) to 102 kHz without reference frequency changes
• Reference Source: Synthesized internal or external with phase-lock capability
Measurement & Processing
• Dynamic Reserve: >100 dB
• Stability: 5 ppm/°C
• Time Constants: 10 µs to 30 ks, with roll-off of 6, 12, 18, or 24 dB/octave
– Key Features
• DSP architecture eliminates pre-filtering requirements
• Exceptional noise floor and dynamic range for faint signal recovery
• Tunable line-frequency rejection for 50/60 Hz environments
• Adjustable sensitivity across nine decades with 1-2-5-10 scaling
• Harmonic measurement capability without reference adjustment
– Typical Applications
• Optical signal detection and characterization
• Materials property measurement
• Low-noise electronics development and testing
• AC signal analysis in electromagnetically noisy settings
