The HI96769 portable photometer is for the measurement of anionic surfactants. 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.
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 - Allows the use of a timer to ensure the appropriate 3 minutes and 30 seconds reaction time is used for the chemical reaction. At the end of the timer countdown 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
Present in waters and wastewaters, surfactants are discharged via aqueous waste from households, industrial laundering, and other cleansing operations. Generally present in detergents and other cleaning agents, a surfactant molecule consists of a strongly hydrophobic group and a strongly hydrophilic group, permitting solubility in both aqueous and nonaqueous media. When the hydrophilic group is negatively charged, it is deemed an anionic surfactant; when the hydrophilic group is positively charged, it is deemed a cationic surfactant.
The HI96769 uses an adaptation of the USEPA method 425.1 and the Anionic Surfactant as MBAS method per Standard Methods for the Examination of Water and Wastewater to measure anionic surfactant concentrations of less than 3.50 mg/L (ppm) (as sodium dodecylbenzenesulfonate [SDBS]). When the methylene blue reagent is added to samples containing anionic surfactants, the sample will turn a blue 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 anionic surfactant determination, a narrow band interference filter at 610 nm (orange) allows only orange 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 HI96769 is available as a kit (HI96769C) which includes:
- Portable Photometer
- Sample cuvettes (2)
- 25 mL glass vial with cap
- Plastic pipettes (3)
- CAL Check™ standards with certificate
- Cuvette cleaning cloth
- Rugged carrying case
- Carrying case has thermoformed insert for meter and accessories
CAL Check™ standards with certificate
The HI96769-11 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
- Light tight
- Protects from accidental breakage
Anionic Surfactants Range 0.00 to 3.50 mg/L (ppm) (as SDBS) Anionic Surfactants Resolution 0.01 mg/L (ppm) Anionic Surfactants Accuracy ±0.04 mg/L ±3% of reading Anionic Surfactants Method adaptation of the USEPA method 425.1 and Standard Methods for the Examination of Water and Wastewater, 20th ed, 5540C, Anionic Surfactants as MBAS Battery Type/Life 9V battery Automatic Shut-Off after ten minutes of non-use in measurement mode; after one hour of non-use in calibration mode; with last reading reminder Environment 0 to 50°C (32 to 122°F); RH max 95% non-condensing Weight 360g (12.7oz.) Dimensions 193 x 104 x 69 mm (7.6 x 4.1 x 2.7”) Ordering Information HI96769 is supplied with sample cuvettes (2) with caps, 9V battery, instrument quality certificate and instruction manual. CAL Check™ standards and testing reagents sold separately.