These economical, simple-to-use pocket testers quickly measure conductivity, TDS, or salinity levels accurately while simultaneously displaying the temperature. A large dual-line display makes viewing measurements easy and features indicators for measurement stability, calibration, and battery life. Additional features include a long-lasting, durable electrode with polymer reference electrolyte, auto recognition of calibration standards, and self-diagnostics. The IP67-rated housing features an easy-to-grip design and floats if accidentally dropped in water when sensor cap is on. The testers, powered by four AAA batteries, can operate up to 400 hours continuously. The unit will auto power-off after 8 minutes of nonuse to conserve power.