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🧪 Experimental Tools

Documentation for tools that are functional but still evolving. Interfaces and file formats may change between releases.

Contents

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Export to MATLAB

Experimental
Open Export to MATLAB →

Converts FRF files from your Data Folder into a single .mat file that MATLAB can open directly. Supports TRF, AvC, and AvR formats. Complex FRF data is preserved for AvC files so phase information is available in MATLAB.

In Explore and Convolve, .mat FRF files can be loaded directly. Coherence data (if present in the yspec variable) is shown automatically as a dotted overlay in Explore.

Quick start

  1. Click 📁 Data Folder to select your measurement folder.
  2. Check the boxes next to the files you want to export.
  3. Click Export .mat. The file downloads immediately.

Output variables

Each selected file contributes a set of variables named after the file stem (special characters replaced with underscores). For a file named H01.trf:

VariableContents
labels1×N cell array of all dataset names
H01_freqColumn vector of frequencies (Hz)
H01_mag_dbColumn vector of magnitude (dB)
H01_HColumn vector of complex FRF — AvC files only

Supported formats

FormatNotes
.trf / .trvMagnitude only
.avcComplex FRF + magnitude; exports _H variable
.avrMagnitude only
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WAV Viewer

Experimental
Open WAV Viewer →

Lets you browse the raw WAV captures saved by Acquire and inspect the time-domain waveforms and computed FRF for any individual hit. Useful for diagnosing trigger problems, checking for double-hits, and verifying channel assignment.

Quick start

  1. Click 📁 Data Folder to select your Acquire data folder.
  2. Select a .wav file from the list on the left.
  3. The hammer and microphone time-domain plots update immediately.
  4. The FRF computed from that single hit is shown in the lower plot.

Plots

PlotDescription
HammerTime-domain signal from the impact channel. The trigger threshold is shown as a dotted line; the hammer cutoff as a vertical green line.
MicrophoneTime-domain signal from the mic channel with its cutoff line.
FRFH1 estimate computed from this single hit, overlaid with coherence.

Settings

Click Settings in the toolbar to adjust the trigger threshold, pre/post trigger window lengths, and channel swap (hammer on left vs. right input). These settings are shared with Acquire.

WAV file format WAV files saved by Acquire are two-channel (stereo): by default channel 1 (left) is the hammer and channel 2 (right) is the microphone. When Swap channels is enabled in Acquire's Template & Settings, the channels are reversed. The WAV Viewer reads the same setting automatically.
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WAV Reader

Experimental
Open WAV Reader →

Turns one long two-channel recording into a complete test run. Where Acquire captures hits live, WAV Reader works after the fact: you record the whole session in any audio app, then split it here into per-tap WAVs and per-position TRFs. It is a browser port of the LabVIEW Main_WAV_Reader.vi.

Quick start

  1. Click 📂 Open WAV… and pick your recording. It must be two-channel — hammer and microphone.
  2. Check First channel matches your file. The default, Microphone, means the left channel is the mic and the right is the hammer — the order Acquire writes.
  3. Drag the two yellow cursors on Complete Data Set to bracket the section you want. Type into the Window boxes for exact values.
  4. Set Threshold so every tap is found and nothing else is. Drag the purple line on the Hammer plot to adjust it visually, and watch the hit count in the status line.
  5. Set Positions and Taps/Position. The status line tells you when the hit count does not match what you declared.
  6. Click Export…, name the instrument and test, choose the destination folder, and export.
Getting the threshold right The default of 0.2 comes from the LabVIEW panel and suits a strongly-driven hammer channel. Quieter recordings need a much lower value — check the hammer peak on the plot first. The sidebar flags any position that came up short of its declared tap count.

Parameters

ParameterMeaning
Duration (s)Length of each extracted segment. Also the minimum spacing between hits — a second crossing inside this window is ignored, which is what rejects double-bounces.
offset (s)Pre-trigger lead-in kept before each threshold crossing.
Positions / Taps per PositionHow the detected hits are grouped. Hits are assigned in time order: the first Taps/Position hits become position 1, and so on.
Set TypePrefix for the position labels. H gives H01, H02, … matching Acquire.
ThresholdLevel the hammer channel must cross to register a hit.
Hammer / Microphone cutoffIn Settings. Each channel is zeroed past its cutoff, measured from the trigger — the same treatment Acquire applies.
MethodSqrt(H1·H2) (the LabVIEW default) or plain H1. See below.

Plots

PlotDescription
Complete Data SetThe whole recording, both channels. The yellow cursors and the shaded band show the selected window.
HammerThe selected tap's impact pulse, zoomed to the live part. The purple dashed line is the threshold and can be dragged.
MicrophoneThe same tap's mic response, with its cutoff marked.
Hammer SpectrumThat pulse's spectrum, normalised to a 0 dB peak. A pulse that rolls off inside your band of interest will distort the FRF there.
FRFAveraged over all hits, or over one position via the Showing selector. Coherence is overlaid along the bottom.

What Export writes

Into the folder you choose, using exactly the layout Acquire produces, so the result opens directly in Explore and Modal Analysis:

PathContents
<instrument>/<test>/raw/<test> H01_001.wavOne 16-bit stereo WAV per tap — left channel microphone, right channel hammer.
<instrument>/<test>/TRF/<test> H01.trfOne TRF per position, averaged over that position's taps, written with fComplex=2.0 so it carries complex FRF plus coherence.
<instrument>/<test>/<test> H.avcComplex (phase-coherent) mean of the per-position FRFs.
<instrument>/<test>/<test> H.avrMean of the per-position magnitudes. Always at or above the AvC in magnitude.
<instrument>/<test>/Settings.jsonRun-settings snapshot, same shape as a desktop Acquire run, plus a source block naming the WAV it came from.
<instrument>/<test>/Notes.txtRun header plus “Translated from <file>.wav by WAV Reader” and the section of the recording used.
Sqrt(H1·H2) The exported magnitude is the geometric mean of the H1 and H2 estimators, carried on H2's phase. H1 under-reads when the hammer channel is noisy and H2 over-reads when the mic channel is; the geometric mean sits between them. Where H2 is undefined — at the nulls of a short hammer pulse, where the input spectrum vanishes — that bin falls back to H1. Choose H1 from the Method selector to match Acquire's estimator instead.