Low Drift, High Accuracy
frequency counter with rubidium timebase
SR625 ... $6,950 (U.S. list)
The SR625 combines the atomic accuracy of a rubidium timebase with the best available
single-shot time resolution ( 25 ps) of any counter — at an unbelievable low price. It measures time
interval, frequency, period, phase, pulse width, event counting, and much more.
• Rubidium atomic timebase
• 2 GHz prescaler input
• 25 ps single-shot time resolution
• 11-digit frequency resolution (1 s)
• Statistical analysis & Allan variance
• GPIB and RS-232 interfaces
The SR625 Frequency Counter consists of a frequency counter (SR620), a high-accuracy
rubidium timebase (PRS10), and a 2 GHz input prescaler. The rubidium timebase ensures
excellent frequency accuracy with a long-term drift of less than 5 × 10–11/month.
The SR625 is ideal for critical measurements like clock jitter, pulse-to-pulse timing, oscillator
characterization, and frequency stability. Please contact us for details.
Stanford Research Systems (408)744-9040