Adding a sensor

This page walks through registering a sensor asset and configuring its measurement channel(s), field by field. Every field described here is also explained by an info tooltip (ⓘ) directly in the UI — clicking a tooltip brings you back to the matching section on this page.

1. Create the asset

Go to Assets → New Asset, choose asset type sensor, and fill in name, manufacturer/model, serial number, and (optionally) a datasheet, location, and owning team. Saving creates the asset with an auto-generated ID (e.g. OG-00042).

2. Add a channel

A sensor asset can have one or more channels — one per physical quantity it measures. Most single-purpose sensors (a thermocouple, a pressure transmitter) have exactly one channel; a multi-parameter probe might have several. On the asset detail page, use Add channel and give it a Channel ID (a short label unique to this asset, e.g. CH1).

3. Configure the channel

Physical quantity

The physical quantity defines the type of measurement (e.g. temperature, pressure) and determines the applicable units and calibration procedures. Choose the one that best matches the sensor's primary measurement — this drives which units appear in every unit dropdown below.

Measurement type

Some physical quantities have more than one measurement mode. The clearest example is pressure: a sensor can report absolute pressure (relative to a vacuum) or gauge pressure (relative to atmospheric pressure). Where a physical quantity has defined options, a Type dropdown appears under Physical quantity; where it doesn't need one (e.g. temperature), the field is hidden entirely.

Measurable range, unit & technology

Enter the channel's measurement range (min/max) and display unit. Once a range is set, every "% FS" (percent of full scale) option below becomes available, since a percentage needs a span to convert against. Technology (e.g. RTD, thermocouple, strain gauge) sits to the right of physical quantity, and the physical quantity's unit sits to the right of the range — purely descriptive fields with no effect on calculations.

Output signal

The sensor's raw output — type (analog / digital / frequency / resistance / capacitance), value range, and unit — sits directly under the measurable range, in the same min–max/unit column layout. This is what the sensor actually outputs electrically, which may differ from the physical unit (e.g. a 4–20 mA current loop representing 0–100 °C).

Accuracy value

Maximum deviation between the sensor output and the true value. Smaller means more accurate. Choose % FS as the unit to express this as a percentage of the measurable range instead of an absolute value — see The "% FS" convention below. This is the manufacturer/nominal accuracy spec, and it's what Open Gauge compares a calibration's measured error against to decide pass/fail — see Decision rules.

Resolution

Smallest change in input the sensor can detect and represent in its output. Resolution feeds automatically into every calibration's uncertainty budget as a Type B (rectangular) contribution — see The uncertainty budget.

Uncertainty (±)

Quantifies doubt about the measurement result, expressed as ±value. This is the manufacturer's nominal/expanded uncertainty spec. It pre-fills a per-calibration "Sensor nominal accuracy" field in the calibration wizard (still editable there) as an optional Type B contribution to that calibration's uncertainty budget — opt-in, because folding it in unconditionally risks double-counting against the fit-residual term computed from the calibration's own data.

Drift rate

Rate at which the sensor output shifts over time without any change in the measured quantity. Purely informational on the channel — Open Gauge's own drift detection is computed from actual calibration history, not from this manufacturer spec; see Drift metrics.

Response time (ms)

Time for the sensor output to reach a defined percentage of its final value after a step input change.

Bandwidth (Hz)

Maximum frequency of input changes the sensor can accurately follow.

Calibration role

A checkbox, "Reference standard" (default: unchecked/No). Check it to mark this channel as a reference standard, so it can be selected as the traceability reference when calibrating other assets against it — see Calibration overview for how internal calibrations use a reference asset.

The "% FS" convention

Accuracy, Resolution, and Uncertainty each pair a numeric value with a unit dropdown. That dropdown offers the channel's compatible physical units (e.g. °C for a temperature channel) plus, once Range min/max are filled in, a "% FS" option as the first choice. There's no separate "accuracy type" field to set — picking a real unit (like °C) means the value is absolute; picking % FS means it's a percentage of the range span, and Open Gauge converts it to an absolute value internally (value/100 × (range_max − range_min)) wherever it's used in a calculation.

After saving

Once a channel is saved, every filled-in value is visible directly in the channel list on the asset page — no need to re-open the edit form to check what was configured.

Next steps

With a channel configured, you're ready to run your first calibration — see Calibration overview, or work through a complete numeric example in Worked examples.