Total Hardness and pH Portable Photometer-Meter Only - HI97736

The HI97736 measures two important water quality parameters: pH and total hardness. Total hardness refers to the presence of magnesium and calcium. Hardness from magnesium and calcium is common in groundwater due to rainwater dissolving these minerals as it flows or filters through the ground. Hardness reduces the effectiveness of soaps and detergents. It can also cause scaling of pipes including in cooling and heating systems.

The HI97736 offers two methods within one meter. pH determination uses the phenol red method; total hardness uses an adaptation of the Standard Methods for the Examination of Water and Wastewater, 23rd
Edition, colorimetric method.

When the appropriate reagent is added to the sample, it will cause a color change. In most cases the greater the concentration in the sample the deeper the color. The associated color change is then colorimetrically analyzed according to the Beer-Lambert Law. This principle states that light is absorbed by a complementary color, and the emitted radiation is dependent upon concentration. For determination of pH and total hardness, a narrow band interference filter at 525 nm allows only green light to be detected by the silicon photodetector and omits all other visible light emitted from the LED. As the change in color of the reacted sample increases, absorbance of the specific wavelength of light also increases, while transmittance decreases. Using a pre-programmed curve a result is then displayed.

The HI97736 has an innovative optical system that offers superior performance in accuracy, repeatability, and the short amount of time it takes to perform a measurement. This compact, waterproof meter is extremely user friendly with a tutorial mode that walks the user graphically, step-by-step, in performing a measurement. The use of a backlit dot matrix LCD allows the use of virtual keys which makes the operation of the meter very intuitive including selecting different units of measure, reviewing GLP data, recalling the last 50 measurements, and customizing the meter to user preferences.

HI97736 is completely waterproof including the cuvette holder that is designed with ridges to protect the optical path from getting scratched by the cuvette and a gasketed battery compartment that holds three common AA batteries. The compact design fits comfortably in the hand for use in the field or on a table for benchtop use. The LCD is backlit for easy viewing under all conditions.

HI97736 FEATURES/BENEFITS:

Stable Light Source:

• The internal reference system of the HI97736 photometer compensates for any drifts due to power fluctuations or ambient temperature changes. With a stable source of light the readings are fast and stable between your blank (zero) measurement and sample measurement.

High Efficiency Light Source:

• LED light sources offer superior performance compared to tungsten lamps. LEDs have a much higher luminous efficiency, providing more light while using less power. They also produce little heat, which could otherwise affect electronic stability.

High Quality Filters:

• Improved optical filters ensure greater wavelength accuracy and allow a brighter, stronger signal to be received. The end result is higher measurement stability and less wavelength error.

Greater Light Yield:

• A focusing lens collects all of the light that exits the cuvette, eliminating errors from imperfections and scratches that may be present in the glass. The use of the convex lens reduces the need for indexing cuvettes.

CAL Check Functionality:

• Hanna's exclusive CAL Check feature allows for performance verification and calibration of the meter using NIST traceable standards. Our CAL Check standard vials are developed to simulate a specific absorbance value at each wavelength to verify the accuracy of subsequent readings.

Large Cuvette Size:

• The sample cell of the HI97736 fits a round, glass cuvette with a 25 mm path length. The relatively long path length of the sample cuvette allows the light to pass through more of the sample solution, ensuring accurate measurements even in low absorbance samples.

Intuitive Dot Matrix Display:

• The HI97736 is designed with a backlit, graphic LCD. With virtual keys, a battery status indicator, and error messages. Users will find the meter interface intuitive and easy to read. A dedicated help key provides information relating to the current meter operation, and can be used at any stage in the setup or measurement process to show contextual help.

Auto-off Protection:

• The meter uses three common AA batteries that allow for about 800 measurements to be taken. The auto-off feature automatically shuts off the meter after 15 minutes of inactivity in order conserve battery life.