The HI88713 is a high accuracy benchtop turbidity meter. The meter is supplied complete with AMCO-AEPA-1 turbidity standards used for calibration and performance verification. The HI88713 meets and exceeds the requirements of ISO Method 7027 for turbidity measurement.
Proportional and non-proportional turbidity measurement modes
USB for data transfer
The HI88713 benchtop turbidity meter is specifically designed for water quality measurements, providing reliable and accurate results, especially in the low turbidity range. It is based on an advanced optical system that ensures accurate and long-term stable results, and minimizes stray light and color interferences. Regular calibration with the supplied standards compensates for variations in the intensity of the tungsten lamp. The 25 mm round cuvettes made of special optical glass ensure repeatability of turbidity measurements.
Outstanding Features
4 measurement modes – The HI88713 has four options for turbidity measurement: FNU, FAU, NTU and non-ratio. The turbidity range for each mode is 0.00 – 1000 FNU, 10.0 – 4000 FAU, 0.00 – 4000 NTU (ratio mode), and 0.00-1000 NTU (non-ratio mode).
Multiple units of measure – Turbidity measurement results can be read in FNU, FAU, EBC and NTU Units
ISO Compliance – HI88713 meets the requirements of ISO 7027 method for turbidity measurement.
Calibration – The HI88713 features a robust calibration function that compensates for lamp aging or changes. Calibration can be performed using the supplied calibration solutions or user standards. Two, three, four, or five-point turbidity calibration is possible using the supplied standards (<0.1, 15, 100, 750, and 2000 NTU). Calibration points can be changed if user standards are used.
AMCO AEPA-1 – The AMCO AEPA-1 standard provided is recognized as a primary standard of USEPA. The non-toxic standard is made of styrene divinylbenzene polymer that is uniform in size and density. The standard solution is reusable and stable with a long shelf life.
GLP Data – The HI88713 features complete GLP (Good Laboratory Practice) functionality allowing traceability of calibration conditions. Data includes calibration points, date, and time.
Record data – Up to 200 measurements can be stored in internal memory and recalled at any time.
Data transmission– For further storage or analysis, recorded data can be downloaded to a Windows computer using the USB port and HI 92000 software
Tutorial Mode – Unique guidance modes provide additional information to assist the user during measurements. When activated, the instrument displays explanations and a confirmation button when further operations are required.
Contextual help – Context-sensitive help is always available by simply pressing HELP. Clear and easy-to-read on-screen instructions quickly and easily guide users through setup and calibration.
LCD graphic display – A graphical LCD display provides a user-friendly interface. All messages are in easy-to-read text.
Turbidity is one of the most important parameters used to determine the quality of drinking water. Turbidity is considered a characteristic for identifying pathogens in drinking water. In natural waters, turbidity measurements are performed to assess the general quality of water and its suitability for applications involving aquatic organisms. Wastewater monitoring and treatment were once based solely on turbidity control. Nowadays, turbidity measurements at the end of wastewater treatment are necessary to verify that values are within regulatory standards.
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 primarily caused by the suspended solids present. The higher the turbidity, the greater the amount of scattered light. Even a pure liquid will scatter light to some extent, meaning that no solution has a turbidity value of zero.
The ISO standard for measuring turbidity uses infrared wavelengths of light that are outside the visible spectrum. The main advantage of the ISO method over the EPA method is the reduction of color interference. The EPA method uses a tungsten lamp that produces light that contains all wavelengths of light that we see as white. A colored solution will be absorbed by the additional wavelength of light which will affect the turbidity value. Since the ISO standard method is the visible wavelengths of light that are external to the sample, it does not affect the measurement. The USEPA prefers the tungsten lamp because it provides better accuracy at low ranges and drinking water is colorless. The requirements of a photometer according to ISO 7027:1999 depend on the scale. Diffuse radiation measurement is usually used for low range turbidity measurements (drinking water) with FNU measurements. Reduced radiation measurement is for high turbidity samples (polluted water) and FAU measurements. The design criteria for each method are:
Measurement of diffuse radiation of low turbidity water (0 FNU to 40 FNU):
Measurement of attenuation of radiation flux at high turbidity (40 FAU to 4000 FAU)
HI88713 meets measurement standards according to ISO 7027.
Operating principle
Light beams passing through the sample are scattered in all directions. The intensity and pattern of scattered light are affected by many factors, such as the wavelength of the incident light, particle size and shape, refractive index, and color. The optical system consists of a tungsten lamp, a scattered light detector (90°), and a transmitted light detector (180°).
When measuring turbidity in proportions, the instrument's microprocessor calculates the NTU value from the signals arriving at the two detectors using a color correction and noise compensation algorithm. The optical systems and measurement technique also compensate for changes in lamp intensity, reducing the need for frequent calibration.
When measuring non-proportional turbidity, NTU and FNU values are calculated from the signals on the scattered light detector (90°).
In FAU mode, turbidity is calculated from the signal arriving at the scattered light detector.
The lower detection limit of a turbidimeter is determined by stray light that is detected by the sensors but not by light scattering from suspended particles. The optical system is designed to have very low stray light, providing highly accurate results for low turbidity samples.
The AMCO AEPA-1 HI88713-11 standards ensure measurements are traceable to a standard reference material. These standards are used to calibrate and verify turbidimeters.
Supplied with Certificate of Analysis (COA)
– Production batch number
– Expiration date
– Standard value @25°C
– NIST
Box:
– Light blocking
– Impact resistant
SPECIFICATIONS
FNU scale |
0.00 to 9.99 FNU, 10.0 to 99.9 FNU, 100 to 1000 FNU |
FNU Resolution |
0.01 FNU, 0.1 FNU, 1 FNU |
FNU Accuracy |
±2% stray light value |
FAU scale |
10.0 to 99.9 FAU, 100 to 4000 FAU |
FAU Resolution |
0.1 FAU, 1 FAU |
FAU Accuracy |
± 10% value |
NTU scale by ratio |
0.00 to 9.99 NTU; 10.0 to 99.9 NTU; 100 to 1000 NTU 0.00 to 9.99 EBC; 10.0 to 99.9 EBC; 100 to 980 EBC |
Resolution NTU by ratio |
0.01; 0.1; 1 NTU; 0.01; 0.1; 1 EBC |
Accuracy NTU by ratio |
±2% stray light value, ±5% value above 1000 NTU |
The scale NTU not proportional |
0.00 to 9.99 NTU; 10.0 to 99.9 NTU; 100 to 4000 NTU 0.00 to 9.99 EBC; 10.0 to 99.9 EBC; 100 to 245 EBC |
Resolution NTU not proportional |
0.01; 0.1; 1 NTU; 0.01; 0.1; 1 EBC |
Accuracy NTU not proportional |
±2% stray light value |
Select scale |
Automatic |
Repeatability |
±1% value or stray light, whichever is greater |
Lost light |
< 0.1 NTU (0.05 EBC) |
Light probe |
silicon photovoltaic cells |
Method |
ISO 7027 |
Measurement mode |
normal, average, continuous |
Turbidity standard |
< 0.1, 15, 100, 750 and 2000 NTU |
Calibration |
2, 3, 4 or 5 points |
Light source |
IR LED |
Screen |
40 x 70 mm (64 x 128 pixels) graphic LCD with backlight |
Memory |
200 records |
Connect |
USB |
Environment |
0 to 50°C (32 to 122°F), RH max 95% non-condensing |
Source |
12 VDC adapter (included) |
Size |
230 x 200 x 145 mm |
Mass |
2.5 kg |
Guarantee |
12 months for body |
Supply includes |
HI88713 is supplied with sample cuvettes and caps (6), HI88713-11 calibration cuvettes, silicone oil, cuvette wiping cloth, adapter, instructions |