Agilent / HP / Keysight 5370B

This counter is achieved by a unique phase lockable phase startable oscillator, used with a digital vernier interpolation scheme that eliminates the ± count quantization error present in most time-interval counters.

It's statistical functions include mean, maximum, minimum, and standard deviation within the selected sample size.

This unit allows both positive and negative time interval measurements that are useful for differential phase measurement.

Other features include automatic calibration of systematic errors and easy display of triggers.

Performance, automation, and ease of use make this the premier time interval measurement counter for applications in component testing, radar/laser ranging, nuclear systems, calibrations labs, computer peripherals testing, digital communications (jitter analysis), and IC tester verification.