The SR625 Frequency Counter is a NIST traceable frequency counting standard for calibrating base stations, transmitters and other types of communication systems. The SR625 Frequency Counter consists of frequency counter (SR620), high-accuracy rubidium timebase (PRS10), and 2 GHz input prescaler.
The combination of the SR620 and the prescaler allows direct frequency measurements up to 2 GHz with twelve digits of resolution in a 100s measurement. The rubidium timebase ensures excellent short-term stability (<2 × 10-11 Allan variance (1 s)) and long-term drift (<5 × 10-11/month). The SR625's warmup time is less than ten minutes rendering it ideal for field applications.