HI93703 Hanna portable turbidimeter (0.00 to 1000 FTU)

Device description

• The HI93703 portable turbidity meter is specially designed for water quality measurements, providing reliable and accurate readings, even within low turbidity ranges.
• The instrument is based on a state-of-the-art optical system that guarantees accurate results, ensures long-term stability, and minimizes stray light and color interference.
• Periodic calibration with the supplied standards compensates for any variation in the intensity of the tungsten lamp.
• The 25 mm cuvettes made of special optical glass guarantee the repeatability of turbidity measurements.
• Calibration of up to three points
• Bucket security system
• Waterproof keyboard

This turbidimeter complies with RD 487/2022 of Legionellosis

• RD 487/2022 Legionellosis

Turbidity description

• Turbidity is one of the most important parameters for determining the quality of drinking water.
• It was regarded as essentially an aesthetic feature of drinking water, however there is now significant evidence that controlling turbidity is competent protection against pathogens.
• In natural waters, turbidity measurements are taken to determine the general quality of the water and its compatibility in applications involving aquatic organisms.
• The control and treatment of wastewater were based solely on the control of turbidity.
• Currently, it is necessary to measure the turbidity at the end of the wastewater treatment process to verify that the values are within the regulations.
• The turbidity of water is an optical property that causes light to be scattered and absorbed, rather than transmitted.
• The scattering of light passing through a liquid is mainly caused by the suspended solids present.
• The higher the turbidity, the greater the amount of scattered light. Even a very pure liquid will scatter light to some degree, since no solution has zero turbidity.
• The ISO standard for turbidity measurement uses the infrared wavelength of light, which is outside the visible spectrum.
• The main benefit of the ISO method over the EPA method is the reduction of color interference.
• The EPA method uses a tungsten lamp that produces light containing all visible wavelengths that we perceive as white.
• A colored solution will be adsorbed by a complementary wavelength which will affect the turbidity reading.
• Since the ISO method is outside the visible wavelength of light, the color of the sample does not interfere with the measurement.
• The USEPA uses the tungsten lamp because it provides better accuracy at low ranges and drinking water should be colorless.

ISO 7027:1999 requirements

The requirements for an optical turbidimeter to perform the measurement of diffuse radiation used in low range measurements (i.e. drinking water), expressed in nephelometric units of formazin according to ISO 7027:1999 are:

• Measurement of diffuse radiation for water with low turbidity (0 FNU to 40 FNU)
• The wavelength of the incident radiation will be 860 nm.
• The spectral bandwidth of the incident radiation shall be less than or equal to 60 nm
• There shall be no divergence from the parallelism of the incident radiation and any convergence shall not exceed 1.5°.
• The measurement angle, between the optical axis of the incident radiation and that of the diffuse radiation will be 90 or +/- 2.5°.
• The opening angle should be between 20° and 30° in the water sample
• HI93703 equipment meets and exceeds the measurement criteria specified by ISO 7027.

Operating principle

• The light beam passing through the sample is scattered in all directions.
• The intensity and pattern of the scattered light is affected by many variables, such as the wavelength of the incident light, the size and shape of the particles, the refractive index, and the color.
• The HI93703 optical system includes an LED and a scattered light detector (90°).
• The lower detection limit of a turbidimeter is determined by the stray light that is detected by the sensors, but not by that which is caused by light scattering from suspended particles.
• The HI93703 optical system is designed to have very little stray light, providing highly accurate results for low turbidity samples.

General characteristics

• Simple Beam Design: The HI93703 measures turbidity using a 90° light detector for stray light detection. Turbidity measurements can be made in the range of 0.00 to 1000 FTU.
• ISO Compliance – The HI93703 meets and exceeds the requirements of ISO 7027 method for turbidity measurements using an infrared LED light source. As this meter has been designed to follow this ISO method, units are displayed in FTU (Formazine Turbidity Unit); FTU is equivalent to the other internationally recognized unit of NTU (nephelometric turbidity unit).
• Calibration – The HI93703 has a powerful calibration function that compensates for variation in light intensity. Calibration can be performed using the supplied calibration solutions or with user-prepared standards. A two or three point turbidity calibration can be performed using the supplied standards (0, 10, and 500 FTU).
• AMCO AEPA-1 Primary Turbidity Standard: The standards supplied by AMCO AEPA-1 are recognized as a primary standard by the USEPA. These standards are non-toxic and are made from styrene-divinylbenzene polymer spheres, which are uniform in size and density. The standards are reusable and stable, with a long shelf life.
• Last Calibration Date – Allows the user to store the last calibration date. Retrieving the last calibration date is simple, you just need to press the “DATE” button on the front of the meter.
• Low Battery Indicator: The “LO BAT” indication will appear in the lower right corner of the screen when the batteries are low and need to be replaced. At this point, the instrument can still perform approximately 50 measurements. When the battery is too low to make reliable measurements, a message will appear and the meter will automatically turn off.

Technical data

• Range: 0.00 to 1000 FTU
• Resolution: 0.01 (0.00 to 50.00 FTU); 1 (50 to 1000 FTU)
• Accuracy: ±0.5 FTU or ±5% of reading (whichever is greater)
• Calibration: Three points (0 FTU, 10 FTU and 500 FTU)
• Light detector: Silicon photocell
• Light Source: Infrared LED
• Battery type / life 1.5V AA (4): approximately 60 hours of continuous use or 900 measurements; automatic shutdown after 5 minutes of inactivity
• Environmental conditions: 0 to 50°C ; max HR 95% (non-condensing)
• Dimensions: 220 x 82 x 66mm
• Weight: 510g

Presentation

• 1 HI93703 Turbidimeter
• 4 AA size 1.5V batteries
• 1 glass bowl