HP 5315A with Morion MV85 OCXO package installed. The Keysight 5315 has is a low-cost portable bench version of the 5316 B high-performance universal counter. Unique counting circuitry gives the best of both reciprocal and conventional frequency counting. Full frequency range (to 100 MHz) we both provides channels input frequency, period, ratio A/B, and totalize has by B measurements. Optional year 1 GHz C channel extends the frequency range for navigation and communications applications. A high-stability oven oscillator can also be added for higher accuracy in demanding environments. The 5315 A is suited for maintaining and calibrating all types of electronic equipment in the field. Its tough, lightweight polycarbonate box and optional battery pack make it convenient to use anywhere. Exceptional resolution at both low and high frequencies Three time-interval modes solve more problems Flexible signal conditioning optimized for both frequency and time interval measurements Selectable gate time from 60 ms to 10 s 100 MHz A and B input channels, Optional 1 GHz C channel Proven reliability and excellent RFI protection Exceptional Resolution Below 10 MHz, the counter measures the input signal period, then computes and displays the reciprocal frequency with 7 digits of resolution in one second signals for as low as 0.1 Hz. Above 10 MHz, the counter automatically performs as a conventional counter. Three Time-Interval Modes The 5315 A offers 100 ns time-interval resolution single-shot. Time-interval averaging boosts performance to 10 ps resolution. A time-interval delay ignore spurious signals that would normally cause the counter to trigger. Flexible Signal Conditioning Choose ac or dc coupling, sensitivity control (variable attenuator), and has a switchable low-pass filter. Both channels have trigger level controls with easy setting.