PH: Acidity and alkalinity (0.00–14.00 range).
TDS: Total Dissolved Solids, measuring minerals or pollutants in ppm.
EC: Electrical Conductivity, used to gauge nutrient levels in hydroponics.
Salinity: Salt content, critical for saltwater pools and marine tanks.
Temperature: Often includes Automatic Temperature Compensation (ATC) to ensure accuracy across different conditions.