HP 5315B Universal Counter

The HP 5315B Universal Counter is a precision instrument for frequency, period, time interval, ratio, and event totalization measurements across professional testing and calibration environments. Its metal cabinet design provides enhanced EMI reduction and enables rack mounting or stacking. Functionally identical to the 5315A, the 5315B delivers measurement capabilities from 0.1 Hz to 100 MHz on Channels A and B, with an optional Channel C extending frequency measurement to 1 GHz.

– Technical Specifications

Measurement Range
• Frequency: 0.1 Hz to 100 MHz (Channels A/B); 50 MHz to 1 GHz with Option 003
• Period: Direct measurement of input signal period
• Time Interval: Single-shot from 100 ns to 100,000 seconds; averaged resolution to 10 ps
• Ratio: Two-signal ratio measurement
• Totalize: Event counting with manual or external gating

Input Specifications (Channels A and B)
• DC coupling: 0 to 100 MHz; AC coupling: 30 Hz to 100 MHz
• Sensitivity: 10 mV rms to 10 MHz; 25 mV rms to 100 MHz; 75 mV peak-to-peak minimum 5 ns pulses; continuously variable to 500 mV rms
• Impedance: 500 Ω nominal (VSWR <2.5:1 typical)
• Input protection: ±18 V (DC + AC peak), fuse protected
• Features: Attenuator (X1, X20), adjustable trigger slope and level, AC/DC coupling; 100 kHz low-pass filter on Channel A

Input Specifications (Optional Channel C)
• Range: 50 MHz to 1000 MHz (prescaled by 10)
• Sensitivity: 15 mV rms to 650 MHz (-23.5 dBm); 75 mV rms to 1000 MHz (-9.5 dBm)
• Dynamic Range: 36 dB (50–650 MHz); 20 dB (650–1000 MHz)
• Impedance: 50 Ω nominal (VSWR <2.5:1 typical)
• Input protection: ±8 V (DC + AC peak), fuse protected

Time Base
• Frequency: 10 MHz
• Aging: <3 parts in 10⁷/month (standard)
• Temperature Stability: ±5 parts in 10⁷ (0° to 50°C)
• Optional TCXO (Option 001): <1 part in 10⁷/month aging; ±1 part in 10⁹ temperature stability (0° to 40°C)

– Key Features

• Dual-channel baseline with optional third channel for GHz-range measurements
• Prescaled Channel C input for extended frequency range
• Variable sensitivity and adjustable trigger controls for signal conditioning
• Switchable low-pass filtering and impedance coupling options
• Metal cabinet for electromagnetic shielding and mechanical stability

– Typical Applications

Frequency calibration, precision timing analysis, signal ratio verification, and event counting in RF, communications, and instrumentation test environments.