The HP 3561A is a classic single-channel Fast Fourier Transform (FFT) dynamic signal analyzer featuring a frequency range up to 100 kHz. Known for its high accuracy in acoustic, audio, and vibration analysis, it delivers an 80 dB dynamic range alongside comprehensive 1/3 octave and full octave formatting capabilities. Built-in mathematical operations, an internal source generator, and HP-IB programmability make it a highly capable instrument for benchtop and system applications.

Specifications

General

ParameterValue
InterfacesHP-IB (IEEE-488)
DisplayBuilt-in CRT
Built-in Self-TestPower-on and user-initiated self-tests
Calibration ReferenceInternal calibration signal

Physical

ParameterValue
Power Supply110 / 120 / 220 / 240 VAC (+5%, -10%), 48 to 66 Hz, 150 VA max
Operating Temperature0 °C to 55 °C
Dimensions (W×H×D)425 mm × 222 mm × 533 mm
Weight15 kg

Frequency Characteristics

ParameterValue
Frequency RangeUp to 100 kHz
Real-time Bandwidth13 kHz
Frequency Resolution (Narrow Band)400 lines
Resolution at Maximum Span250 Hz (for 100 kHz display span)
Resolution at Minimum Span25.6 microHz (for 0.01024 Hz display span)
Display Span Range0.01024 Hz to 100 kHz

Amplitude & Input Characteristics

ParameterValue
Number of Channels1 channel
Maximum Safe Input Voltage42 V peak
Minimum Full Scale Input Range-51 dBV (2.82 mVrms)
Dynamic Range80 dB
ICP Transducer PowerIntegrated Circuit Piezoelectric current source available
Acoustic FilterA-weighting filter available

Measurement & Analysis Functions

ParameterValue
Measurement FormatsNarrowband, 1/3 octave, full octave
Averaging ModesRMS, RMS exponential weighting, time averaging
Peak Hold ModeCaptures maximum amplitude
Overload Reject ModeExcludes overloaded measurements from averaging
Mathematical OperationsAddition, subtraction, multiplication, division, integration, differentiation
Time Buffer CaptureCaptures narrowband data for post-processing

Display & User Interface

ParameterValue
Display Presentation FormatsSingle trace, top-bottom dual trace, front-back dual trace, map-type format
Waterfall Map CapacityUp to 60 traces
Amplitude ScalingLinear or logarithmic

Connectivity, Interfaces & Storage

ParameterValue
Internal Storage (Standard)Nonvolatile memory for 6 setups and 2 traces
Optional StorageBubble memory (setups, traces, and time capture storage)
HP-IB Plotter and Printer SupportDirect output plotting and printing via HP-IB
Remote ProgrammabilityFully remote programmable via HP-IB

Signal Source (Generator) Characteristics

ParameterValue
Source WaveformsPeriodic chirp, random noise, impulse

Input Characteristics

ParameterValue
Input Impedance1 MΩ shunted by < 100 pF
Input CouplingAC, DC
Common Mode Rejection> 80 dB at 50/60 Hz

Environmental

ParameterValue
Storage Temperature-40 °C to +75 °C
Relative Humidity< 95% at 40 °C (non-condensing)

Frequency

ParameterValue
Number of Lines400 lines
Frequency Accuracy±0.003% of reading

Amplitude

ParameterValue
Spurious Responses<-80 dB relative to full scale
Anti-alias Filter Attenuation>80 dB

Signal Source

ParameterValue
Source Output Impedance50 Ω (nominal)
Source Output Level+10 dBV to -50 dBV (1 V to 3.16 mV rms)

Signal Processing

ParameterValue
Window FunctionsFlat Top, Hann (Hanning), Uniform

Technology

FFT Dynamic Signal Analysis

Applications

Acoustic, audio, and vibration analysis