Microprocessor based designed, and rugged housing with splash proof keyboard. The large backlight LCD displays pH or ORP or Conductivity or DO and Temperature simultaneously. Automatic Temperature Compensation(ATC), Manual Salinity(MSC) and Altitude(MAC) Compensation. Memory function stores and recalls up to 150 points. MAX/MIN and data Lock. Degree ℃/℉ are switchable. Combine special platform and electrode holder, or stirrer(Optional) for measuring convenient. The TDS value is determined by multiplying a conductivity reading by a known ratio in the range of 0.50 to 1.00. Output data for capturing on PC directly via USB or Bluetooth