The HI96720 portable photometer is for the measurement of calcium hardness. Hanna’s portable photometers feature an advanced optical system; the combination of a special tungsten lamp, a narrow band interference filter, and silicon photodetector ensure accurate photometric readings every time. The Hanna exclusive CAL Check™ feature utilizes ready-made, NIST traceable standards to verify both meter validation and calibration. The exclusive cuvette locking system ensures that the cuvette is inserted into the measurement cell in the same position every time to maintain a consistent path length.
Allows for performance verification and calibration of the meter using a CAL Check NIST traceable secondary standard.
Records the date of the last user calibration performed.
Built in timer
Ensures the appropriate reaction time is used for the chemical reaction. At the end of the timer the meter will automatically take the reading. This feature ensures consistency across multiple users.
Indexing indent on meter
The meter has an indent that allows for a lock and key fit with the cuvette cap. This ensures that the cuvette is indexed consistently (same position) in order to maintain the same path length for accurate results.
Cooling Lamp Indicator
It is necessary to maintain a consistent temperature of the optical components in order to maintain a narrow wavelength band of light. This photometer has a cooling lamp indicator that is displayed for a short period of time before each measurement in order to allow the components to cool and obtain the highest accuracy possible.
Messages on display alerting to problems including no cap, over range and under range readings, and light source error.
Automatic shut off after 10 minutes of non-use when the meter is in measurement mode. Prevents wastage of batteries in the event the meter is accidentally not turned off.
Battery status indicator
The instrument has a battery level indicator to display remaining life as follows:
- 3 lines for 100 % capacity
- 2 lines for 66 % capacity
- 1 line for 33 % capacity
- Battery icon blinks when the capacity is less than 10 %.
Units of measure
Appropriate unit of measure is displayed along with reading.
Water, with exception to distilled water, contains dissolved salts (magnesium and calcium carbonates). The concentration of these salts determines the water hardness, which can be expressed in 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 pipe rusting in water heating and cooling systems, reverse osmosis, and demineralization plants.
The HI96720 uses an adaptation of the Standard Methods for the Examination of Water and Wastewater, 18th edition, calmagite method to measure calcium hardness concentrations of less than 2.70 mg/L (ppm). When the reagent is added to samples containing calcium salts, the the sample will turn a red hue; the greater the concentration, 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 calcium hardness determination, a narrow band interference filter at 525 nm (green) allows only green light to be detected by the silicon photodetector and omits all other visible light emitted from the tungsten lamp. As the change in color of the reacted sample increases, absorbance of the specific wavelength of light also increases, while transmittance decreases.
The HI96720 is available as a kit (HI96720C) which includes:
- Portable Photometer
- Sample cuvettes (2)
- Caps (2)
- CAL Check™ standards with certificate
- Cuvette cleaning cloth
- 1 mL syringe with tip
- Rugged carrying case
- Carrying case has thermoformed insert for meter and accessories
*Reagents ordered separately
CAL Check™ standards with certificate
The HI96720-11 CAL Check™standards are used for calibration and performance verification of photometers with the CAL Check™ function.
Supplied with Certificate of Analysis
- Lot number
- Expiration date
- Standard value @ 25°C
- Reference meter NIST traceable
Provided storage containers
- Light tight
- Protects from accidental breakage
|Hardness, Calcium Range
|0.00 to 2.70 mg/L (ppm) calcium hardness
|Hardness, Calcium Resolution
|Hardness, Calcium Accuracy
|±0.11 mg/L ±5% of reading
|Hardness, Calcium Method
|adaptation of the Standard Methods for the Examination of Water and Wastewater, 18th ed. Calmagite method
|after ten minutes of non-use in measurement mode; after one hour of non-use in calibration mode; with last reading reminder
|0 to 50°C (32 to 122°F); RH max 95% non-condensing
|192 x 104 x 69 mm (7.6 x 4.1 x 2.7”)
|320g (11.3 oz.)