SR625 Rubidium Stabilized Frequency Counter
The SR625 Frequency Counter is a NIST traceable frequency counting standard for calibarating base stations, transmitters and many other types of communication systems. It combines the high resolution and wide variety of features found in the SR620 counter with the atomic accuracy of a rubidium timebase.
Low Drift, High Accuracy
The SR625 Frequency Counter consists of a SR620 Time Interval Analyzer plus a high accuracy rubidium timebase and 2 GHz input prescaler. The combination of the SR620 and the prescaler allow direct frequency measurements up to 2 GHz with twelve digits of resolution in a 100 second gate. The rubdium timebase ensures both excellent short term stablity (<1.0x10 -11 Allan Variance (10 s)) and low long term drift (<5x10-11/month).
Simple, Portable Operation
The SR625's warmup time is less than ten minutes, making it ideal for field applications. An additional back panel output provides a rubidium stablized 10 MHz signal which can be used to drive other test equipment such as synthesizers or spectrum analyzers. The standard GPIB and RS-232 interfaces allow for complete control and data acquisition from any laboratory computer. The SR625's performance makes it the standard for remote applications or laboratory calibration.