Stanford Research SR430 – Multichannel Scaler/Averager

The Stanford Research SR430 Multichannel Scaler/Averager is a high-speed data acquisition instrument designed for photon counting, event timing, and signal analysis. It combines amplification, discrimination, bin clocking, and real-time averaging into a single unit, eliminating the need for external analysis systems. The SR430 handles count rates to 100 MHz with no interchannel dead time, making it ideal for time-resolved measurements in LIDAR, time-of-flight mass spectrometry, and fluorescence decay analysis.

Technical Specifications

• Count Rate Capacity: 100 MHz maximum


• Bin Width: 5 ns to 10 ms (selectable); external bin clock input supported for custom sizing


• Bins per Record: 1,024 to 32,768 in 1k increments


• Records per Scan: 1 to 65,536, or continuous free-run mode


• Input Impedance: 50 Ω


• Analog Input Range: ±300 mV


• Input Sensitivity: 10 mV minimum pulse amplitude


• Discriminator Range: ±300 mV, adjustable in 0.2 mV steps


• Discriminator Accuracy: 2 mV + 1%


• Pulse-Pair Resolution: 10 ns (typical)


• Discriminator Output: NIM level (0 to –0.7 V, active low) with 20 ns insertion delay


• Trigger Input Impedance: 10 kΩ


• Trigger Threshold: –2.000 V to +2.000 V in 1 mV steps


• Power Consumption: 60 W


• Power Supply: 100, 120/220, 240 VAC, 50/60 Hz

Key Features

• Selectable positive or negative slope for discriminator and trigger functions


• Record-by-record averaging with add/subtract capability and polarity control


• External inhibit input for selective record exclusion


• External toggle input for dynamic polarity selection


• Real-time on-screen data display and analysis


• Hardcopy output to Epson-compatible dot-matrix and HP LaserJet printers, plus HP-GL plotters


• Data transfer to hardcopy at 16,384 bins in 500 ms


• 3.5" DOS-compatible floppy drive (720 kB) for program and data storage

Interfaces IEEE-488.2, RS-232, and Centronics printer connectivity enable remote instrument control and data retrieval.

Typical Applications Time-of-flight systems, single-photon detection experiments, temporal correlation measurements, and any application requiring synchronized event counting with high timing resolution.