GT668 measurements include Time Interval Error, 1 PPS Monitoring, Jitter measurements, PLL & Clock Jitter, Spread Spectrum Modulation, PLL Lock Time, Frequency, Period, Pulse Width, Skew, Tpd, Rise/Fall Time, and more. GuideTech’s GT668 has high-accuracy 10MHz OCXO time-base & NIST traceable calibration.