• Fast 250,000 measurements/sec to internal memory
• Ultrahigh 50 ps single-shot time interval resolution
• 12 digits/sec frequency resolution
• 2,600 individual measurements/sec via GPIB/USB bus
• Internal memory storage of 3.5M measurments
• Zero dead-time frequency, period
• Continuous data streaming during, not after, measurements
• Graphic display and numeric presentation modes
• Programmable pulse output 0.5 Hz to 50 MHz
• Modulation Domain Analysis using TimeView software
• Frequency range to 300 MHz – options to 3, 8, 14 and 20 GHz

Fast Speed and Ultrahigh Resolution

The CNT-91 frequency counter / timer / analyzer, is the highest performance counter for measurement, analysis and calibration of frequency, time interval and phase. In production test systems, R&D, calibration lab, or in the field; the CNT-91 outperforms any counter on the market for speed, resolution, statistical analysis and processing capabilities.

The CNT-91 provides high 50 ps single shot time resolution or 12 digits/sec frequency resolution for capturing very small time and frequency changes. And, displays up to 14 digits on values obtained.

The CNT-91 frequency counter processes an exceptionally fast 250,000 measurements/sec to internal memory with a maximum of 3.5M measurements stored.

Graphic Display and Multi-mode Presentation

Pendulum Instruments are the only frequency counters supporting unique graphic presentation of results including histograms, trend lines, and modulation. On-screen statistical processing of random signal distribution and measurement changes vs. time, from slow drift, to fast jitter and modulation. Complete analysis including mean, min., max. p-p, standard deviation, and Allan deviation are viewable in both graphic and numeric format.

With TimeView, Modulation Domain Analyzer software (optional), the CNT-90XL statistical processing is more powerful and provides expanded analysis capabilities.

Zero Dead-Time Captures Individual Periods

Unlike standard gated frequency counters, the CNT-91 provides continuous time-stamping of events capturing all individual periods, back-to-back without dead-time, measuring every complete event cycle without event interpolation errors. This process allows for a least-squares linear regression of multiple measurements, adding 3 or more digits to the measurement resolution.

Microwave Frequency Range and Time Base

The CNT-91 features a frequency range of 0.001Hz to 300 MHz standard with options to 3, 8, 14 and 20 GHz. All models are available with optional internal OCXO time-bases for applications requiring higher measurement stability. Two OCXO options are available: one with very high stability (0.01ppm/month), and one with an ultra-high stability (0.003ppm/month).

GPIB/USB Increased Throughput and Efficiency

USB and GPIB (IEEE 488.2) interfaces are standard with the CNT-91. The GPIB interface is SCPI/1999 compliant and includes a HP53131A emulation mode for easy inclusion in test systems designed for older model counters. This eliminates the need to re-program system commands when replacing older counters with the modern CNT-91.

With a fast bus transfer speed of 2,600 individual measurement results/sec via GPIB or USB, the CNT-91 saves test system time and money by increasing throughput, up to 90%.

Technical Documentation

CNT-91 Specifications (376 kB)
EC Declaration of Conformity (46 kB)
TimeView, Modulation Domain Analyzer, Specifications (229 kB)
LabView Driver for CNT-90