Hanna HI96711 Offers

The portable photometer is for the measurement of free and total chlorine, and features 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 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.

Features

• CAL Check™ - Allows for performance verification and calibration of the meter using a CAL Check NIST traceable secondary standard
• GLP - 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
• Error messages - Messages on display alerting to problems including no cap, over range and under range readings, and light source error
• Auto-shut off - 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 reaming 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

Significance of use

As one of the oldest and most common forms of disinfection, chlorine improves water quality by destroying disease-producing microorganisms and by reacting with other organic and inorganic substances. Chlorine levels must be actively monitored to ensure sufficient chlorine is present for disinfection, as well as to control adverse effects such as taste, odor, and potential reactions with organic matter to form harmful disinfection byproducts.

The photometer uses an adaptation of the USEPA method 330.5 and Standard Method 4500-Cl G to measure free and total chlorine concentrations of less than 5.00 mg/L (ppm). When the DPD reagent is added to samples containing free chlorine, the sample will turn a pink 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 complimentary color, and the emitted radiation is dependent upon concentration. For free and total chlorine 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.

Simple to use

1. Press "CAL Check" to enter validation procedure
2. Insert CAL Check Standard A cuvette and press "Zero." When the display reads "0.0," remove cuvette
3. Insert CAL Check Standard B cuvette and press "Read"
4. Compare the displayed reading with the value on the Certificate of Analysis. If the reading is not in the stated range, the meter needs to be calibrated