What is the difference in single-shot time interval resolution between the 53131A and 53132A?

The Keysight 53131A provides a time interval resolution of 500 ps, while the Keysight 53132A offers a higher resolution of 150 ps.

Does the 53181A support frequency ratio measurements?

Yes, the Keysight 53181A can perform frequency ratio measurements, but this functionality requires the installation of the optional Channel 2.

What low-pass filtering options are available on these counters?

Both the Keysight 53132A and the Keysight 53181A feature a switchable 100 kHz low-pass filter to eliminate high-frequency noise from measurements.

Keysight 53130 Series Frequency Counters

3 models with full specifications from Keysight Technologies (Agilent HP).

The Keysight Technologies (formerly Agilent HP) 53130 Series consists of the 53131A, 53132A, and 53181A high-performance frequency counters. This series is designed for engineers, system integrators, and technical professionals who require precise frequency and time-interval measurements on the benchtop or within automated test equipment (ATE) environments. While all three models share a common mechanical chassis and standard DC to 225 MHz base channel architecture, they are differentiated by their channel counts, measurement resolutions, and application focus. The 53131A and 53132A function as universal counters with dual standard channels, whereas the 53181A is designed specifically as a single-channel RF frequency counter. Understanding the distinct performance tiers of these instruments—such as the 12-digit resolution of the 53132A versus the 10-digit resolution of the 53131A and 53181A—allows engineers to select the exact model that aligns with their signal measurement and resolution requirements.

Base Frequency Range: DC to 225 MHz
Standard Timebase: 10 MHz
Common Dimensions: 212.6 × 88.5 × 348.3 mm
Operating Temperature: 0 to 55 °C

Models in this series

Model	Type	Dimensions (W×H×D)	Display	Frequency Range
53131A	Universal	212.6 × 88.5 × 348.3 mm	Vacuum fluorescent	Up to 12.4 GHz (frequency-option dependent)
53132A	Universal	212.6 × 88.5 × 348.3	Vacuum Fluorescent Display (VFD)	DC to 225 MHz
53181A	Universal	212.6 × 88.5 × 348.3	Vacuum Fluorescent Display (VFD)	dc to 225 MHz

Common Platform Specifications

All models in the Keysight 53130 Series share a standard physical form factor and several fundamental hardware characteristics. Built in a 2U half-rack chassis, they feature a high-visibility Vacuum Fluorescent Display (VFD). The standard front-panel input channels cover a frequency range of DC to 225 MHz with user-selectable input impedance of 1 MΩ or 50 Ω, and switchable AC or DC coupling.

For connectivity, GPIB comes standard across the series. Additionally, these instruments share identical operating temperature envelopes of 0 to 55 °C and are powered by a universal supply accommodating 100-120 V (50, 60, or 400 Hz) and 220-240 V (50 or 60 Hz) systems, drawing a maximum of 170 VA.

Channel Configurations and RF Options

The primary distinction between models lies in their input channel architecture:

Keysight 53131A and 53132A: These universal counters feature two standard channels (Channels 1 and 2). Both models can be expanded with an optional Channel 3, extending the frequency range up to 12.4 GHz.
Keysight 53181A: Optimized for RF applications, this model provides one standard channel (Channel 1). An optional Channel 2 can be integrated to extend frequency range capabilities to 1.5 GHz, 3.0 GHz, 5.0 GHz, or 12.4 GHz.

While the universal counters are optimized for time-interval measurements, the 53181A RF counter is tailored for frequency, period, peak voltage, and frequency ratio measurements (when the optional Channel 2 is installed).

Resolution and Analysis Capabilities

The models offer different performance tiers for demanding precision applications:

Keysight 53131A: Offers 10 digits per second frequency resolution and 500 ps time interval resolution. It features basic math functions, including Scale and Offset, alongside automated limit tests.
Keysight 53132A: Delivers 12 digits per second frequency resolution and 150 ps single-shot time interval resolution. It adds RS-232 to the standard GPIB interface and includes integrated statistical analysis (Average, Min/Max, Standard Deviation) alongside a switchable 100 kHz low-pass filter.
Keysight 53181A: Provides 10 digits per second resolution. It supports a switchable 100 kHz low-pass filter, scale/offset math, and full statistics calculations. It also accepts external reference input frequencies of 1 MHz, 5 MHz, or 10 MHz.

Frequently asked questions

What is the difference in single-shot time interval resolution between the 53131A and 53132A?: The Keysight 53131A provides a time interval resolution of 500 ps, while the Keysight 53132A offers a higher resolution of 150 ps.
Does the 53181A support frequency ratio measurements?: Yes, the Keysight 53181A can perform frequency ratio measurements, but this functionality requires the installation of the optional Channel 2.
What low-pass filtering options are available on these counters?: Both the Keysight 53132A and the Keysight 53181A feature a switchable 100 kHz low-pass filter to eliminate high-frequency noise from measurements.