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
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.
Figure 1: ClearView db How it Works
Specifications: ClearView db Process Analyzer (Photometer)
| Design | Fiber Optic Dual-Beam Photometer |
|---|---|
| No. of Channels | 1 Sample Channel, optional 2nd Sample Channel, optional Turbidity Monitoring for 1st Channel only |
| Number of Detectors/Filters | 2 – 6, any combination of detector types except 3 xInGaAs max |
| Filters | As per customer requirements, max 6 individual filters |
| Detector Types | Si (450 nm – 1050 nm) InGaAs (800 - 1650 nm) xInGaAs (1000 - 2150 nm, TE cooled), max 3 |
| Light Source | Tungsten-Halogen, >4000 hours typical |
| Spectral Range | 450 nm to 2150 nm |
| Photometric Noise | <50 μAU 450-2100 nm 1 minute rms |
| Photometric Drift | <500 μAU rms/ °C |
| Wavelength Drift | Property of Filter |
| Response Time | 1 second, minimum. User settable |
| Fiber Size | 400, 500, or 600 μm diameter, single strand |
| Fiber Type Fused Silica | Ultra Low-OH (optimum range: 450 nm - 2150 nm) |
| Fiber Connectors | SMA 905 |
| Outputs (analog) | Up to 6 for a 1 Channel Unit, Up to 4 per Channel for a 2 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, Class I Division 2, Z-Purge, NEMA 4x, Class I Division 1, IECEx, ATEX |
| Power | 24 VDC, 3 A |
| Environmental | 0 – 45°C, 0 – 90%, sun and rain sheltered |
| Dimensions (H x W x D) | GP – 14”x 12”x 6” [36 cm x 31 cm x 15 cm], CID2 – 16”x 20”x 6” [41 cm x 51 cm x 15 cm], Explosion proof – 16”x 17”x 10” [41 cm x 43 cm x 26 cm] |