ClearView® db VIS-NIR Dual-Beam Photometer
GUIDED WAVE’S ClearView db photometer is the first commercially available true dual-beam filter photometer. A primary attraction of any photometric analyzer is its low cost, however, the compromise is usually performance. Guided Wave has dramatically improved photometer performance by adding our unique dual-beam optics, which provides long-term, stable operation. The flexible configurations of the ClearView db also meets many online analysis requirements for liquid and gas process streams.
Typical Applications
Color — ASTM or saybolt in fuels
OH (hydroxyl) number for polymer reaction end point
Water content in solvents
Haze in diesel fuel with turbidity option
NaOH in water
ClearView db Benefits
Stable dual-beam design decreases drift due to lamp aging —yielding long-term performance
Several enclosure options means lowest installation costs
Six filter positions make multi-parameter analysis a possibility
Optional second sample channel for lower cost per sample point
Optional turbidity monitoring
Compatible with a wide range of flow cells and insertion probes
Low maintenance
Long life Tungsten-Halogen Lamp (>4000 hours typical)
Dual-beam performance lengthens time between required probe cleanings
Figure 1: ClearView db How it Works
Principle of Operation
Photometry is fundamentally the measurement of the intensity of light. Observable on many levels, changes in light intensity occur as a result of interactions with different materials. Further, the Beer-Lambert Law describes a useful relationship between light and matter. Matter absorbs light in measurable amounts at specific wavelengths. The degree of absorption correlates to the concentration of matter that is exposed to the light across a known optical distance, or pathlength. Thus, chemical concentrations and physical characteristics of a process stream sample can be accurately analyzed. Effective analyzer design permits this principle to be taken online powerfully exploiting the science and achieving a high level of process control.
Each successful ClearView db application is defined by the calibration. The calibration consists of absorption data corresponding to analytical values that describe the state of the process stream. Wavelengths specified for the application are represented by filters installed in the photometer. If and when changes occur in the process, the ClearView db measurements reflect this instantaneously.
Complete Analyzer System
The ClearView db is a complete analytical system comprised of three main components: 1) the photometer, 2) the fiber optic cables, and 3) the sample interface. The photometer both transmits the source light and quantifies the light that was not absorbed by the sample (Figure 1). Optical grade fiber cables are used to carry the light from the photometer to the sample and back. Using high performance fiber cables permits the sample interface to be located up to 100 meters from the photometer.
Often the success of an analyzer hinges on the proper selection of the sample interface. The ClearView db is compatible with the large selection of Guided Wave rugged and efficient sample interfaces. Hence, photometry is now an option in even the harshest environments.
