Settings reference¶

Open via the Settings button or menu. Four tabs: Measurement, Display, File, Output. All values are persisted per-user-profile in config.json (gitignored, in the working directory). Cross-references in this page link to Concepts for term explanations.

Measurement tab¶

General instrument¶

Setting	Default	Range / type	What it does
GPIB Address	`GPIB0::24::INSTR`	VISA resource string	Where to find the instrument. Detect Devices scans all available VISA buses and offers the result in a picker. Machine-local: stored keyed by hostname rather than in the shared profile, so a NAS-shared `config.json` works across lab PCs with different wiring. Any legacy single-address slot is auto-lifted on first save.
Sampling Rate	`10.0 Hz`	`0.1 – 100 Hz`	Default readings per second. Each measurement tab has its own spinbox that overrides this. Each per-tab spinbox is dynamically capped based on the active (NPLC × auto-zero × filter × offset-comp) combination; if you commit a value above the cap the status bar reports the cap and suggests the cheapest single setting change to reach the requested rate. See Concepts → Rate-cap predictor.
NPLC	`1`	`0.01 – 10`	Integration time per reading. Lower = faster + noisier; higher = slower + cleaner.
Settling Time	`0.2 s`	`0 – 10 s`	Delay after output enable before the first reading. Lets DUT + instrument stabilize.

Resistance defaults¶

Applied to the Resistance tab on launch; the tab itself has live widgets that override these per-run.

Setting	Default	Notes
Test Current	`1 mA`	DC current sourced through the DUT
Voltage Compliance	`5 V`	Maximum allowed across the DUT
Measurement Type	`2-wire`	Or `4-wire` for Kelvin

Voltage Source defaults¶

Setting	Default	Notes
Source Voltage	`1.0 V`	Accepts negative values
Current Compliance	`100 mA`
Duration (hours)	`0` (= run until stopped)	Set non-zero for unattended runs

Current Source defaults¶

Setting	Default	Notes
Source Current	`1 mA`	Accepts negative values
Voltage Compliance	`5 V`
Duration (hours)	`0` (= run until stopped)
Stop on compliance	`False`	Auto-Stop when compliance is reached. Useful for protecting sensitive samples in source-V too.

Advanced instrument settings¶

Setting	Default	Notes
Enable Hardware Filter	`True`	Use the Keithley's built-in averaging filter (see Concepts → Hardware averaging filter)
Filter Type	`repeat`	`repeat` (N readings → 1 result, then repeat) or `moving` (running average)
Filter Count	`5`	`1 – 100`
Enhanced accuracy in Resistance mode	`True`	Offset-compensated ohms. See Concepts → Enhanced R mode.
Touch-safety warn threshold	`30 V`	`0 – 1100 V`. Voltage at or above this triggers the warning modal before run start. `0` disables. See Concepts → Touch-safety warning.
Suppress touch-safety warning for this profile	`False`	Equivalent to clicking "Don't show again" on the modal. Uncheck to re-enable.

Auto-Zero lives on each tab, not in Settings

Pre-v1.10 it was here, but per-tab makes more sense: 4PP and vdP force auto_zero='on' regardless; sensor modes (resistance, source_v, source_i) expose the knob on the tab itself so re-tuning the speed/accuracy trade doesn't require a Settings dialog detour.

Display tab¶

Setting	Default	Notes
Enable Real-time Plots	`True`	Disable for high-rate runs (>50 Hz) where rendering eats CPU
Resistance Plot Color	`#D55E00` (Wong vermillion)	Matches the V/I/R/P live-readout label colors
V Source Plot Color	`#0072B2` (Wong blue)
I Source Plot Color	`#009E73` (Wong green)
Data Buffer Size (points)	`0` (Unlimited)	`0` = no cap. pyqtgraph downsamples on render (peak-mode + `clipToView`) so a 17-hour / 270k-sample run is ~13 MB and stays smooth. Set a finite cap only if RAM is tight.

Pre-v1.10 buffer-size default was 1000

Old configs that explicitly set buffer_size to a small number silently truncated the live trace on overnight runs. New default is unlimited; existing configs override unless you reset.

File tab¶

Setting	Default	Notes
Auto-save Interval	`60 s`	How often to flush data to disk during a measurement. Lower = less data loss on crash, but more I/O.
Data Directory	`measurement_data`	Root for run output. A subdirectory is created for each user. Browse... button opens a folder picker.

Output tab¶

See Data Outputs for the full format reference; this tab just selects which backend to use.

Setting	Default	Notes
Output format	`csv`	One of: `csv` (default, single `.csv` with `#`-prefixed metadata header), `hdf5` (requires `h5py`), `csv+legacy_json` (pre-2.0 dual emit for back-compat with downstream pipelines)
Compression	`never`	Applies only to the `csv` backend. `never` / `always` / `auto`. Default is `never` because Excel, Origin, and most lab tools can't open `.csv.gz` directly. HDF5 is always internally gzip-compressed regardless.
Auto-compression threshold	`5 MB`	Only used by the `auto` compression policy

HDF5 grayed out?

If h5py isn't installed, the HDF5 option is disabled with a tooltip explaining why. pip install h5py and restart to enable it.

Configuration storage¶

Settings are kept in config.json in the working directory (gitignored — per-user, not portable). Structure mirrors the four Settings tabs:

{
  "measurement": {...},
  "display": {...},
  "file": {...},
  "output": {...},
  "users": ["alice", "bob"],
  "last_user": "alice",
  "user_settings": {
    "alice": {"measurement": {...}, ...},
    "bob": {"measurement": {...}, ...}
  }
}

When a user is selected, their per-user overrides deep-merge on top of the global defaults. Editing this file by hand works but is error-prone — prefer the dialog. If the file gets corrupted, delete it and ResistaMet will recreate from DEFAULT_SETTINGS (in resistamet_gui/constants.py).

The top-level Profiles menu has two entries that operate on the currently-active tab (Resistance / Voltage Source / Current Source / Four-Point Probe — Sweep and vdP are excluded):

Save Profile for Current Mode... writes the active tab's measurement settings to a .json file (suggested name <mode>_profile.json). Useful for "sensor A typical run" vs "sensor B typical run" templates that you swap between samples.
Load Profile to Current Mode... reads a .json and applies known fields to the active tab's widgets. Unknown fields are ignored. Legacy fpp_thickness_cm is auto-converted to fpp_thickness_um for backward compatibility.

These are file-level profiles distinct from the per-user settings stored in config.json. They don't move the GPIB address (which is machine-local).

Results Viewer tab¶

A 7th tab "Results Viewer" is included by default. It lets you:

Open any v2.0 .csv or .csv.gz file produced by ResistaMet GUI (also accepts older legacy CSVs)
Pick any column from the dropdown to plot vs elapsed_s
Read the trailing metadata (run mode, sample name, start time) into the status log

No write-back — it's strictly a post-run viewer.

Per-tab settings (not in this dialog)¶

Some settings live on the individual mode tabs because they're per-measurement-context, not session-wide:

Auto Zero — Resistance / Voltage Source / Current Source tabs (each)
Enhanced accuracy — Resistance tab (separate from the global Settings checkbox, which sets the default)
Source Range Auto / Voltage Range Auto — every tab
Cable null — Resistance tab
Delta mode (current reversal) — Four-Point Probe tab Advanced section
Geometry / dopant / temperature — Four-Point Probe tab (drive F84 corrections)
Sample thickness — Four-Point Probe and Van der Pauw tabs
Sweep start / stop / step / direction / per-step delay — I-V Sweep tab

These follow the same per-user persistence — they're written into the user's section of config.json when the user clicks Save Settings on the active tab.