Description
The HI97720 is an advanced portable photometer for measuring calcium hardness in water. This meter offers a superior optical system that uses a reference detector and narrowband interference filters for extremely fast and repeatable measurements.
Water, with the exception of distilled water, contains dissolved salts (magnesium and calcium carbonates). The concentration of these salts determines the hardness of the water, which can be expressed as calcium carbonate or magnesium carbonate. The sum of these two represents the total hardness level. In addition, water hardness is also related to the phenomenon of oxidation of pipes in water heating and cooling systems, reverse osmosis and demineralization plants.
The HI97720 uses an adaptation of the Standard Methods for the Examination of Drinking Water and Wastewater, 23rd Edition, a calmagite method for measuring calcium hardness concentrations up to 2.70 mg/L (ppm). When the reagent is added to samples containing calcium salts, the sample turns red; The higher the concentration, the deeper the color. The associated color change is analyzed colorimetrically according to Lambert-Beer’s Law. This principle states that light is absorbed by a complementary color and the radiation emitted depends on the concentration. For the determination of calcium hardness, a narrowband interference filter at 525 nm allows the silicon photodetector to detect only green light and omits the rest of the visible light emitted by the LED lamp. As the color change of the reacted sample increases, so does the absorbance of the specific wavelength of light, while the transmittance decreases
FEATURES/BENEFITS of the HI97720:
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Stable Light Source:
The photometer’s internal reference system HI97720 compensates for any deviations due to energy fluctuations or ambient temperature changes. With a stable light source, readings are fast and stable between measuring the target (zero) and measuring the sample.
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 energy. They also produce little heat, which could otherwise affect electronic stability.
High Quality Filters:
Improved optical filters ensure higher wavelength accuracy and allow for a brighter, stronger signal. The end result is greater measurement stability and less wavelength error.
Increased Light Output:
A focusing lens collects all the light that comes out of the bucket, eliminating errors due to imperfections and scratches that may be present in the glass. The use of convex lenses reduces the need to index trays.
CAL Check functionality:
Hanna’s unique CAL Check feature enables verification of meter performance and calibration 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 Bucket Size:
The sample cell of the HI97720 fits a round glass cuvette with a path length of 25 mm. The relatively long path length of the sample cuvette allows light to pass through a larger amount of the sample solution, ensuring accurate measurements even in low-absorbance samples.
Intuitive Point Matrix Display:
The HI97720 is designed with a backlit graphic LCD display. With virtual keys, battery status indicator and error messages. Users will find the meter interface intuitive and easy to read. A dedicated help key provides information related to the current operation of the meter and can be used at any stage of the setup or measurement process to display contextual help.
Automatic Shut-Off:
The meter uses three common AA batteries that allow about 800 measurements to be taken. The auto-off feature automatically turns off the meter after 15 minutes of inactivity to conserve battery life.
Specs:
– Hardness (Calcium) Range: 0.00 to 2.70 mg/L (as CaCO3)
– Resolution Hardness (Calcium): 0.01 mg/L
– Hardness Accuracy (Calcium): ±0.11 mg/L ±5% of reading at 25°C
– Hardness (Calcium) Method: adaptation of the Standard Methods for the Analysis of Drinking Water and Wastewater, 23rd Edition, Calmagita Method
– Light Source Photometer/Colorimeter: LED with 525 nm bandpass filter
– Light Detector Photometer/Colorimeter: silicon photocell
– Filter Bandwidth: 8 nm
– Wavelength Accuracy Band Filter: ±1.0 nm
– Type of Bucket: 24.6 mm diameter round (22 mm inside)
– LPG: Yes
– Display: 128 x 64 pixel B/W LCD with backlight
– Log Memory: 50 readings
– Battery Type/Duration: 1.5V AA alkaline (3 pcs.)(Not included) /> 800 measurements (without backlight)
– Auto Power Off: after 15 minutes of inactivity (30 minutes before a READ measurement)
– Ambient: 0 to 50°C (32 to 122°F); HR 0 to 100% (IP67)
– Weight: 380 g (13.4 oz.)
– Dimensions: 142.5 x 102.5 x 50.5 mm (5.6 x 4.0 x 2.0″)
