Complete Analytical System for Measuring Turbidity (NTU) and/or Haze
Turbidity can be used to indicate solid breakthrough in a process. This can be used as an alarm and to invalidate other optical measurements until the problem can be corrected. The Guided Wave Turbidity Analyzer measures the level of suspended solids or non-miscible liquids in a solution via light scattering at 90 degrees. Turbidity values can be found in several different units depending on the application. Two common measurement standards are ASTM Method D4176 (HAZE), and EPA method 180.1 (NTU).
The ASTM method is a visual standard for measuring turbidity (caused by immiscible water in fuels) by viewing cards with black lines of various thicknesses through a 100mm diameter glass jar of solution. The result is a value (called Haze) between 1 and 6, with 1 being the clearest. Haze is typically measured in the refining sector and arises from water beyond the solubility limit. Alarming on this solubility issue allows the refiner to have better control of the fuel quality.
EPA 180.1 measures light scatter at 90 degrees in nephelometric turbidity units (NTU). In this method standards of formazin are available at different NTU levels to be used for calibration. Both of these methods can be easily replicated with the Guided Wave Turbidity Analyzer.
The Guided Wave Turbidity Analyzer system is a complete solution. The “ready-to-go” analytical system includes:
- Analyzer - ClearView® db filter photometer technology
- Fiber optic cables
- Sample interface - insertion probe or flow cell
- Control software and Saybolt application calibration
Accurate, Real-time Reliable Results
The Saybolt Analyzer system utilizes a Guided Wave multi-wavelength ClearView db filter photometer analyzer platform. It may be configured for either one (1) or two (2) independent sample monitoring points. The ClearView db analyzer is configured with application appropriate wavelengths to measure the Saybolt color of the sample. The analyzer employs a dual-beam design – meaning; the system has an continual internal optical reference check that allows it to self-compensate for signal variation due to non-sample conditions. This ultimately provides the system with long term stability. The final product is a total Saybolt Color System that measures the color variation without interference from other factors.
Figure 1 shows a typical trend chart monitoring Saybolt color of a continuous flowing process. Figure 2 shows an initial calibration chart showing the measured values as compared to laboratory standard values.
Turbidity can be easily combined to be part of a measurement system that also measures a color value such as Saybolt color. It also can be an add-on to an existing Guided Wave ClearView db chemical measurement application.
Complete Turbidity Analyzer System
- Unique dual beam optics - for long term, stable operation
- One turbidity channel plus up to two independent measurement points - for added analytical flexibility at reduced cost per point
- High efficiency yet rugged fiber optics - analyzer electronics can be located away from a hazardous sample point
- In-door touch screen or Ethernet (Modbus TCP) - easy local or remote analyzer operation and control
- Analytical calculations are all encoded in the software - answers and alarms are clearly reported
Options for a Custom Solution
Another advantage of the Turbidity Analyzer system is that is can be customized in many ways. For more information about specifications and analyzer operations request ClearView db document #1033 or call Guided Wave.
Guided Wave’s Turbidity Probe and Multi-Purpose Flow Cell (MPFC) with an additional third port can be used for Haze or Turbidity (NTU) measurements along with the Turbidity Analyzer. The 20mm pathlength is appropriate, for example, when monitoring Saybolt color. For more information review product data sheets #1065 and #1051.
The Smart Choice
Guided Wave’s Turbidity Analyzer system delivers accurate, real-time process measurement results. Its linearity and repeatability, as well as its low maintenance requirements make it a cost effective, smart choice to help optimize production, improve yields, ensure consistent product quality and enhance profitability.
Specifications: Turbidity (Haze) Analyzer - Photometer
|Analyzer Technology||Fiber optic dual-beam ClearView db photometer (see also document #1033)|
|Fiber Connectors||SMA 905|
|Light Source||Tungsten-Halogen, >4000 hours typical|
|Photometric Noise||<50 µAU 450-2100 nm 1 minute rms|
|Photometric Drift||<500 µAU rms/ °C|
|Response Time||1 second, minimum. User settable|
|Measurement Range||Haze 1 to 6, NTU 0-1000|
|Measurement Accuracy||Complies with ASTM methods D4176 and EPA method 180.1|
|Power||24 VDC, 3 A; 72 watts|
|Environmental||0 – 45°C, 0 – 90%, sun and rain sheltered|
|Channels||Turbidity monitoring plus up to 2 (two) sample channels|
|Outputs (analog)||Up to 6 for a one channel unit, Up to 4 per channel for a two channel unit, 4 – 20 mA, customer powered|
|Outputs (discreet)||Up to 6 for a 1 channel unit, Up to 4 per channel for a 2 channel unit, contact closures|
|Inputs (analog)||4 (optional) 4 – 20 mA, isolated grounds|
|Local Display||LCD touch screen, color QVGA|
|Communications||Ethernet (TCP Modbus) standard|
|Enclosures||General Purpose NEMA 4 unclassified, Z-Purge, NEMA 4x, CI D2, X-Proof, ICEEx, ATEX, CI D1|