Device Dialog — Calibration

The Calibration tab is where you configure what your device measures (Role) and how raw hardware values are converted into real-world units (Strategy). Without calibration, sensor readings are meaningless raw numbers.

Concepts

Role

A Role defines what the device measures. For example, an ultrasonic sensor can measure either distance (mm) or volume (L) from the same raw data. The role determines:

  • Which unit the sensor reports in
  • Which strategies are available for calibration
  • Which display units are offered

Strategy

A Strategy defines the mathematical method used to convert raw hardware values to real-world values.

Calibration Key

Calibration data is stored per role:strategy combination (e.g., ph:multi_point). This means you can switch between roles without losing calibration data — each combination keeps its own record.

Section 1: Role Selection

Shown when the device template defines multiple roles. Click a role card to select it:

  • The default strategy for that role is automatically applied
  • The strategy selector updates to show only strategies allowed by this role
  • If the role allows only one strategy, it is auto-locked

Section 2: Strategy Selection

Shows available calibration strategies as cards.

ElementDescription
Radio buttonGreen filled circle = Active strategy. Click to set as active.
”Cal” badgeGreen — shown if this strategy has existing calibration data
”No Cal” badgeOrange pulsing — active strategy but no calibration data yet
”Set as Active” buttonMakes a non-active strategy the active one used by the system

You can view and calibrate a strategy without making it active — allowing you to prepare calibration data before switching.

Available Strategies

For Sensors

StrategyIDDescription
OffsetoffsetAdds a fixed correction value to every reading. Simplest calibration.
Linear (2-Point)linearMaps two known raw→real pairs to create a linear equation (y = mx + b). Good for sensors with linear response.
Multi-Pointmulti_pointMaps 3+ reference points for polynomial interpolation. Most accurate for non-linear sensors.
pH Smartph_smartSpecialized wizard for pH sensors using standard buffer solutions (pH 4.0, 7.0, 10.0).
EC Smartec_smartSpecialized wizard for EC/TDS sensors using standard calibration solutions.

For Actuators

StrategyIDDescription
Volumetric Flowvolumetric_flowMeasures the flow rate of a pump (ml/s) by running it for a set time and measuring the output. Used for precise dosing calculations.

Section 3: Calibration Wizard

When you select a strategy card, the calibration area appears below.

If calibration data already exists:

ElementDescription
✓ CalibratedGreen status indicator
Last CalibratedDate and time of most recent calibration
Recorded DataShows the stored calibration points
RecalibrateOpens the wizard to overwrite with fresh data
DeleteRemoves the calibration data

Calibration Wizards

Offset Wizard

  1. Read the current sensor value (or enter manually)
  2. Enter the known correct value
  3. The system calculates the offset = known − measured
  4. Save

Linear Wizard (2-Point)

  1. Place the sensor in solution #1 → click Read → enter the known value
  2. Place the sensor in solution #2 → click Read → enter the known value
  3. Save — the system calculates slope (m) and intercept (b)

Multi-Point Wizard (3+ Points)

  1. For each reference point: click Read → enter the known real-world value → click Add Point
  2. Review all captured points
  3. Save — the system performs polynomial interpolation

pH Smart Wizard

  1. Place sensor in pH 7.0 buffer → Read
  2. Place sensor in pH 4.0 buffer → Read
  3. (Optional) Place sensor in pH 10.0 buffer → Read
  4. Save

EC Smart Wizard

  1. Similar guided wizard for EC calibration solutions
  2. Step-by-step with known standard values
  3. Save

Volumetric Flow Wizard

  1. Enter the test duration (seconds)
  2. Click Run Pump — the system activates the actuator for the specified time
  3. Measure the output volume (ml) and enter it
  4. Save — this rate is used for all future dose calculations