Instrument Data Log (.dat / .log / .asc)
.dat.log.ascSpectrophotometers, chromatographs, sensor loggers, and general scientific instruments exporting text with comment preambles
What it is
Text-based instrument export format that contains comment lines (#, %, ;), key-value metadata blocks, and delimited numeric data tables. Also supports gzip-compressed .dat.gz, .log.gz, and .asc.gz files.
Who produces it
Laboratory instruments, environmental data loggers, and scientific acquisition devices that export structured text logs with header information before the numerical data.
What we read / what we don't read
What we read
- Metadata key-value pairs from comment preambles (# Key: Value, % Key: Value)
- Auto-detected column delimiters (whitespace, comma, tab, semicolon)
- Numeric data columns (float and integer) into high-performance columnar buffers
- Text columns with preserved cell values
- Transparent decompression of gzip-compressed .dat.gz, .log.gz, and .asc.gz files
- Header autodetection with numeric guard: if the first data line is numeric, column names are parsed from the closest preceding comment line or named Column 1..N
What we don't read
- Ragged or multi-block files where the column count changes abruptly mid-stream
- Files with trailing proprietary binary payloads attached after the text data
How to import it into AltaiPlot
- Open AltaiPlot and drag your .dat, .log, or .asc file onto the window, or use File → Import.
- AltaiPlot detects the instrument log structure and parses header comments automatically.
- Preview the extracted metadata and data columns in the preview panel.
- Click Import — the data lands as ready-to-plot columns with metadata attached.
Auditability note: this page's capability claims are sourced fromsrc/renderer/src/engine/v7/import/importers/DatLogImporter.ts:53 — see the full format list for every extension AltaiPlot recognizes.