Analyze: Software for 1-port or 2-port measurements

Impedance plot of 1000µ 63V electrolytic

Release: 0.3

This is a set of programs and scripts to do high precision impedance and transfer function measurements (network analyzer) with PC sound devices.

With an external amplifier and an instrumentation amplifier you will be able to characterize capacitors in the range from 1 pF to 10 mF and inductors in the range from 100 nH to 10 H.

It will also enable you to measure the response of loudspeakers or a listening room. Limited by the maximum frequency your sound device can handle it will also work as network analyzer. The latter may also be used to determine the length of a coaxial cable by measuring the delay.

▼ Index ▷ Usage ▷ Examples ▷ Parameters ▷ Calibration ▷ File format ▷ How it works
▾ Components ▾ Download ▾ Build ▾ History ▾ Contact

Software components

Function	Name	Type	Remarks
Access to the sound device	n/a	platform dependent, external tool required	You need a platform dependent way to record and play 16 bit two channel audio data via a pipe or provide an appropriate character device. On Linux `arecord` and `aplay` will fit your needs. OS/2 has the application `Playrec` 0.20b21. Windows: don't know.
Generation of reference signal and FFT analysis	analyze	C++ application	The core application
Sample configuration	`sample/*.cfg`	Configuration files for analyze	Here are some sample files for different measurement scenarios including calibration.
Helper scripts	`sample/*.sh`	Unix shell scripts	These are scripts to invoke the above sample configurations and setup the sound device. They are only available for bash or sh.
Show the result	`sample/*.gp`	Gnuplot 3.x macros	In general you can use any graphics application to show the results. But only macros for Gnuplot are part of this package.
Statistical analysis of sound data	sampledist	C++ application	General analysis of sound input. Might be used for diagnostics as well as to identify compressed audio content.

Download

Source code and scripts: Repository at github

The program is licensed under GNU GENERAL PUBLIC LICENSE.

Build the package

Preconditions

A C++11 compatible compiler like gcc.
The library FFTW, version 3.x is required. This must be available as shared or static library including the header files. E.g. package libfftw3-dev on Debian based Linux distributions.
Cmake version 2.6 or newer. This is usually available as package cmake in most Linux distributions.

Build

cmake .
make

If everything is fine the executables are built in the current folder. Feel free to contact me if you don't succeed.

Version history

Version 0.3

Added 3 point calibration for high precision impedance measurements.

Version 0.2

Port to Linux
Reworked command line options, breaks compatibility to 0.1x at several places.

Version 0.11

Source tree reorganized.
Fit of the delay.
English translation.

Version 0.1

Internal revision.

Contact

Suggestions, help, complaints (but not too much:-): Email: mueller Klammeraffe maazl Punkt de
Or use the github for bug reports.