Advantest R5361B Frequency counter

The Advantest R5361B is a dual-channel frequency counter designed for precision frequency and period measurements in research, development, and production environments. Channel 1 covers 60 mHz to 1000 MHz with 10 mV sensitivity; Channel 2 extends down to 200 Hz and reaches 100 MHz. The instrument delivers 9-digit resolution and measurement times as short as 0.9 ms, making it suitable for characterizing RF sources, oscillators, and signal generators across multiple frequency bands.

Measurement capability extends beyond simple frequency counting. Period measurements range from 10 ns to 5000 s on Channel B, while positive pulse width measurements span 200 ns to 9000 s. Totalize function operates DC to 50 MHz.

The 8-digit LED display updates with 0.08 s measurement throughput.

Technical Specifications

• Channel 1: 60 mHz to 1000 MHz


• Channel 2: 200 Hz to 100 MHz Measurement Functions


• Frequency measurement


• Period measurement: 10 ns to 5000 s (Channel B)


• Positive pulse width measurement: 200 ns to 9000 s


• Totalize: DC to 50 MHz Input Specifications


• Channel 1: 10 mV sensitivity, 5 V maximum input, 50 Ω impedance, x1/x20 attenuation, AC coupling


• Channel 2: 10 mV sensitivity, 25 mV maximum input, 1 MΩ impedance, AC coupling Performance


• Resolution: 9 digits/s


• Time base stability: 0.0000002 /yr


• Measurement throughput: 0.08 s


• Measurement time: 1 ms to 1000 s


• External time base reference: 10 MHz Physical & Electrical


• Display: 8-digit LED


• Dimensions: 210 mm (W) × 90 mm (H) × 300 mm (D)


• Weight: 2.5 kg


• Power: 100–240 V AC, 50/60 Hz

Key Features

• Dual-channel architecture for simultaneous or independent measurements


• Wide frequency range from 200 Hz to 1 GHz


• High-stability timebase ensures accurate long-term measurements


• GPIB interface for remote control and data acquisition


• Compact benchtop form factor

Typical Applications

• Oscillator and clock frequency verification


• RF source characterization


• Pulse and timing analysis


• Production test and verification


• Laboratory measurement and calibration

Compatibility & Integration The R5361B interfaces via GPIB for integration into automated test systems. Documentation including manuals is available for both R5361B and R5362B models. This is a discontinued product.