The Combo HI 991404 and HI 991405 series meters from HANNA® are designed for continuous, high accuracy pH, EC/TDS and temperature measurements. These microprocessor indicators continuously monitor the three most important nutrient parameters in hydroponics, greenhouses and horticultural applications with a single instrument. These indicators feature a large, dual-level, backlit LCD to give you instantaneous readings of pH, EC or TDS and temperature, even from a distance.

At startup, these indicators perform a self-check to assure proper working condition. HI 991404 and HI 991405 stability indicator and hold features prompt the user when to take the reading and freezes the display for easy and accurate recording.

Calibration and temperature compensation is automatic, while the EC/TDS conversion factor and temperature coefficient (ß) are user adjustable for application-specific measurements.

These instruments are supplied with an advanced, non-clogging double junction pH electrode and a rugged conductivity probe that will withstand even the most aggressive environments. The instruments are powered by a 12 Vdc transformer and are easy to install and use, making them ideal for all continuously monitoring applications.