The HP/Agilent 53131A is a 225 MHz universal frequency counter/timer engineered for precision time and frequency measurements across laboratory, system integration, and production environments. This dual-channel instrument delivers 10-digit frequency resolution and 500 ps time interval resolution, with real-time digital signal processing enabling simultaneous analysis and measurement throughput up to 200 fully formatted readings per second via GPIB. The 53131A measures frequency, period, time interval, pulse width, rise/fall time, phase angle, duty cycle, event totalization, and peak voltage—supported by built-in statistics (average, min, max, standard deviation), automated limit testing with pass/fail indication, and configurable math functions for scaling and offset.
## Technical Specifications
• **Frequency Measurement:** Dual 225 MHz channels; optional third channel extends capability to 3 GHz, 5 GHz, or 12.4 GHz
• **Frequency Resolution:** 10 digits per second
• **Time Interval Resolution:** 500 ps
• **Measurement Throughput:** Up to 200 measurements per second via GPIB
• **Input Impedance:** Selectable 1 MΩ (≈30 pF) or 50 Ω
• **Trigger Level Range:** ±5.125 V with ±(15 mV + 1% of trigger level) accuracy
## Key Features
• Real-time digital signal processing for enhanced speed and accuracy
• Flexible triggering options for precise event capture
• Automated limit testing with visual pass/fail status and external device trigger output
• Analog display mode for at-a-glance measurement status
• 20 stored front-panel setups for rapid configuration recall
• One-button access to frequently used functions
## Typical Applications
Frequency and period analysis, precision timing measurements, phase relationship characterization, pulse parameter analysis, and production-level limit testing with automated reporting.
## Compatibility & Integration
GPIB connectivity supports direct integration with automated test systems and data logging frameworks. Configurable setups enable rapid deployment across multiple test scenarios without manual reconfiguration.

















