Calibration¶

Overview¶

Lab-grade accuracy requires regular sensor calibration. Uncalibrated sensors produce readings that may be accurate enough to detect gross failures but not suitable for precise nutrient dosing. Calibration should be performed at initial setup and periodically thereafter.

pH Sensor¶

A 3-point calibration yields the best accuracy across the operating range (5.5–6.5).

• Deactivate the sensor input before calibrating.
• Rinse probe with distilled water between solutions.
• Allow probe to stabilise in each solution before confirming calibration.
• Frequency: TBD (typically every 1–3 months, or when readings drift).

EC Sensor¶

A 2-point calibration:

• Temperature-compensate calibration solutions to the operating water temperature.
• Frequency: TBD (typically every 1–3 months).

Peristaltic Pumps¶

Volume calibration ensures each pump dispenses the commanded volume accurately.

1. Prime tubing (remove all air bubbles).
2. Command the pump to dispense a target volume (e.g. 10 ml).
3. Measure actual volume with a graduated cylinder.
4. Enter the measured value into the pump calibration (correction factor applied automatically).
5. Repeat for all pumps independently.

Calibration Schedule¶

Sources¶

• Kyle Gabriel: Calibration