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Precision frequency measurement and analysis
Keysight FC1-class frequency counters include the 53210A-53230A. They offer high-resolution capabilities, measurement accuracy, and robust connectivity options. With features like temperature-compensated timebases for long-term stability, built-in analysis tools, and the ability to conduct continuous measurements, Keysight frequency counters provide exceptional performance and ease of use. Optional microwave channels extend the frequency range, while advanced math functions and versatile measurement capabilities support a variety of applications. Easy calibration processes and durable hardware ensure consistent performance. With three models to choose from, select the one you need based on digits of resolution and number of channels. Need help selecting? Check out the resources below.
High resolution
Provides up to 12 digits/second resolution and 20 ps single-shot time interval resolution for precise frequency measurements.
Timebase stability
Incorporates high-quality, temperature-compensated timebases to deliver stable and accurate long-term measurements.
Built-in analysis
Includes integrated analysis and graphing capabilities for direct visualization and interpretation of measurement data enabling deeper insights.
Seamless data capture
Enables gap-free, continuous measurements to support thorough time-domain signal analysis over time.
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Digits of resolution
12 to 15
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Number of channels
1 to 3
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Bandwidth
350 MHz
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Memory
1 M readings
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Measurement functions
Frequency, Period, Frequency ratio, Level
Most popular configurations
FC1-class Frequency Counter, 350 MHz
FC1-class Frequency Counter, 350 MHz
FC1-class Frequency Counter, 350 MHz
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Frequently asked questions
A frequency counter is an electronic instrument used to accurately measure the frequency of a periodic signal, typically in the radio, microwave, or digital domain. Frequency refers to how often a repetitive event occurs in a specific period.
The counter works by counting the number of signal cycles (zero crossings or pulse edges) that occur within a precisely defined time window, known as the gate time. For example, if 1,000,000 cycles are counted during a 1-second gate time, the frequency is 1 MHz.
Frequency counters fall into two basic types: direct counting and reciprocal counting. Understanding the effects of the two different approaches will help you choose the best counter for your needs and use it correctly.
Direct counters simply count cycles of a signal over a known period of time. This period is known as the gate time. The resulting count is sent directly to the frequency counter's readout for display.
Reciprocal counters measure the input signal's period and then reciprocate it to get the frequency. A reciprocal frequency counter will always have the same number of digits of resolution regardless of the input frequency.
If your resolution requirements are flexible and you are not too concerned with speed, a direct counter is the economical choice. However, you will need a reciprocal counter for faster, higher-resolution measurements. Reciprocal counters also offer continuously adjustable gate times, allowing you to achieve the desired resolution within the minimum time frame.
The measurement accuracy of a frequency counter is strongly dependent on the stability of its time base. The time base establishes the reference against which the input signal is measured. The better the time base, the more accurate the frequency counter measurements.
The quartz crystal which is the heart of every frequency counter's time base, is a mechanical device. Since it is a mechanical device, the crystal is susceptible to physical disturbances that can change the frequency at which it vibrates, which ultimately impacts the frequency counter's accuracy. The cumulative effect of these various disturbances is known as crystal aging. It is this aging that you are compensating for when you calibrate the counter.