With a built-in Rubidium atomic resonance-controlled frequency reference, the PM 6685R is the most accurate frequency counter on the market and it has the additional benefit of full portability.

High stability, high accuracy and short warm-up time make this instrument ideal for high-accuracy calibration procedures outside the calibration laboratory environment, such as in base station transmitters of large telecommunications networks like GSM.

The short warm-up time makes that the PM 6685R is ready for use quickly, for example after transport or change of location inside a building.