HI99191 pH Meter For Low Ionic Strength Water

​​​​​​​Features

•   Easy to clean and keep clean•   Specialized electrode•   Mulit-level LCD display•   On-screen tutorial messages for calibration and set up•   Automatic Temperature Compensation•   Automatic one or two point calibration•   BEPS, Alerts the user in the even that low battery power could adversley affect the readings•   Battery % displayed on startup•   Compact, heavy duty, and waterproof

The Hanna Instruments HI 99191 is a waterproof portable pH/temperature meter designed specifically for measuring the pH of drinking water.

The pH of drinking water is a vital measurement. If the pH is on the acidic side then the water will be corrosive to the distribution system and water pipes in homes. The pH of water also influences other properties including taste, odor, clarity, and disinfection. In the United States the pH of water is determined by a pH meter according to EPA method 150.1 and Standard Methods 4500-H.

Most drinking water plants use either surface water  (lakes, rivers, and streams) or groundwater as their point source. Surface water is typically lower in mineral content resulting in lower conductivity/TDS readings. Groundwater that has percolated through limestone, dolomite or gypsum will have a higher mineral content than surface water. There are sources of groundwater that are also very low in mineral content.

Measuring pH of water low in minerals is difficult. The lower the mineral content the less conductive the water will be. Low conductivity water presents a challenge since the pH meter is an electrochemical system that relies the solution being measured to be conductive. The HI 99191 uses the FC 215 amplified pH electrode. The FC 215 has three ceramic junction s in the outer reference call that allows for pH measurement in low conductivity solutions. 

The 99191 measures pH from -2.00 to 16.00 pH and temperature from -5.0 to 105.0 oC  (23.0 to 221.0 oF). Automatic calibration is done at 1 or 2 points and all readings are automatically compensated for temperature variations. Indicators for stability, battery percentage, and calibration instructions are viewed on the primary display. The HI 99191 uses three 1.5V AAA batteries for an exceptional battery life of 1200 hours of continuous use.