Most frequency counters work by using a counter which accumulates the number of events occurring within a specific period of time. After a preset period known as the gate time (1 second, for example), the value in the counter is transferred to a display and the counter is reset to zero. If the event being measured repeats itself with sufficient stability and the frequency is considerably lower than that of the clock oscillator being used, the resolution of the measurement can be greatly improved by measuring the time required for an entire number of cycles, rather than counting the number of entire cycles observed for a pre-set duration (often referred to as the reciprocal technique). The internal oscillator which provides the time signals is called the timebase, and must be calibrated very accurately.


The MF2400C series lineup is composed of three frequency counters: the MF2412C (20 GHz), the MF2413C (27 GHz), and the MF2414C (40 GHz). This series is ideal for evaluating mobile radio communications devices and circuits, and can also measure the carrier frequency and pulse width of burst signals. In addition to displaying measurement results on the 12-digit vacuum fluorescent display (VFD), frequency values can be read using the analog display function, which can be used for monitoring and is especially useful for adjusting the frequency of oscillators. Furthermore, the template function is perfect for assessing whether or not results fall within upper and lower frequency limit specification. Because the evaluation result is output from the AUX connector on the back panel as a Go/No-go signal, an easy-to-use, automatic measurement system can be configured using the GPIB function.

Keysight Technologies Inc.

Keysight's frequency counter product family includes RF, Universal, and Microwave Frequency counter products, Time-To-Digital Converters.

Marvin Test Solutions Inc.

The GTX22x0 family of PXI universal time interval counters offer many of the measurement and timing functions of high-end stand-alone frequency counters, including accumulate, auto ratio, frequency, fast frequency (GTX2220 and GTX2230 only), period, ratio, single period, test clock, time interval, time interval delay, totalize, totalize gated, totalize gated once, & pulse width.