225MHz Universal Counter/Timer, 10 Digits; no options The Agilent (now Keysight) 53131A universal counter has the capability to do the job quickly and correctly from fast signal processing to automated limit tests. The 53131A has frequency resolution of 10 digits per second, 500 ps time interval resolution and a complete set of test and analysis features. The unit comes with two 225 MHz channels, and you can choose an optional third channel that measures up to 3 GHz, 5 GHz, or 12.4 GHz. Features: Measurements include frequency, frequency ratio, time interval, rise/fall time, phase, duty cycle, positive/negative pulse width, totalize, peak voltage, time interval average and time interval delay Automated limit tests and one-button measurement setups for fast, easy operation Two 225 MHz input channels, plus optional third channel up to 12.4 GHz Built-in statistics feature lets you simultaneously measure average, min/max, and standard deviation 10 digits per second, 500 ps time interval resolution GPIB Standard, USB optional