Key features of the YK-2005WA Multi-Function Water Quality Meter include: * Integrated pH/ORP, conductivity, dissolved oxygen, and TDS measurement functions * pH measurement range: 0 to 14.00 pH, ORP measurement range: ±1999 mV * Conductivity measurement range: 200 uS/2 mS/20 mS/200 mS * Dissolved oxygen measurement range: 0 to 20.0 mg/L * Automatic temperature compensation feature * Built-in real-time data logger storing up to 16,000 data points * Supports RS-232/USB output * Equipped with a large LCD display * Operates on DC 1.5V or DC 9V power supply