f luminescent, optical and fluorescent measurement of dissolved oxygen has introduced it's third generation Model FL-
Waynesville, NC (PRWEB) February 3, 2004
Environmental Instruments, with 16 years experience in the field o3 luminescent dissolved oxygen analyzer. The FL-3, with patented technology utilizing superior materials of construction, is able to offer a FIVE(5) year warranty for the sensor. Their original
FL-1 sensor (7 years old) is still operating and it appears the new sensors will last from 7-10 years. The CYPRUS Microsystems processor will allow additional probes and devices to be controlled by the same processor.
Galvanic and polargraphic based dissolved oxygen sensors for environmental monitoring have been to date the predominate methods for dissolved oxygen measurement in the past. Constant cleaning of the sensors; the need for membrane and electrolyte replacement, probe fouling and re-calibrating of the instrument can be so demanding that monitoring and more profoundly, control, can be frustrating, if not impossible. The FL-3 requires no membranes, electrolyte and very little probe maintenance or calibration.
Luminescent (fluorescent, optical) based oxygen sensors have gained acceptance and surprising municipal and industrial wastewater treatment plant operators with their dependability. Low maintenance and no consumables or replacement parts to worry with are a hallmark of these sensors. This in turn reduces hours of lost time for maintenance and eliminates the cost of replacement parts. Another very important feature is that fluorescent-based sensors do not consume oxygen and require no flow across them to work. They also perform very well in harsh environments that normally destroy other conventional sensors.
PRINCIPAL OF OPERATION:
The oxygen present in water as dissolved oxygen migrates into the sensor, which is a 1mm by 15mm disc. The oxygen associates with a fluorescent compound in the disc, which causes it to glow when stimulated with a blue laser diode (LED). The fluorescent compound is not consumed in this process. The oxygen also is not consumed or chemically altered. The glow from this passive event is detected from behind the disc with the water on the opposite side. This arrangement creates a stable optical link to the disc. The disc is a combination of Teflon and Silicon polymers. The sensor is permanently mounted and is not replaceable.
PERFORMANCE- Municipal and Industrial
Environmental Instruments, LLC offered several municipalities and industrial clients a 30 to 60 day trial with a promise that the unit could be returned if it did not perform to standards agreed upon by both parties. The results were both impressive and somewhat perplexing for these installations. At one installation, the Knoxville Utility Board, Knoxville TN., ran a 30 day trial in one of their aeration basins and purchased the unit after the unit met the agreed upon performance standards. They did not have to wipe the probe for eight months after the installation. This consisted of pulling the probe from the basin, wiping the sensor with a rag and replacing the probe in the basin. Although very pleased with the extremely low maintenance of the unit, they were also perplexed by spikes recorded by the unit of up to 10 mg/l in the basin. The average D.O. for this particular basin was around 1.0 to 2.0 mg/l. An alarm was set within their computer monitoring system to indicate when the spikes occurred. In response to the alarm they went to the basin to physically cross check the reading of the fluorescent monitor with a hand held D.O. meter. After determining that these were real events, KUB is now in the process of tracking the source of these spikes and have purchased 7 additional units to begin the process of controlling their blowers. It also appears that these units can be used in the KUB pre-treatment programs. The City of Waynesville, NC also participated in a trial, resulting in huge savings on energy consumption and also 60% reduction in chlorine consumption. Similar trials were run at Dunkirk, NY, Sonoma County, Ca., West Chicago, IL., Cargill, Blair, NE. and Johnson & Johnson, just to name a few of the other trial sites that resulted in purchases. All of these trials provided excellent results, greatly exceeding the expectations of the clients and proving that fluorescent based dissolved oxygen technology has provided a new paradigm for the consistent and dependable monitoring and controlling of dissolved oxygen.
Environmental Instruments, 828-452-7776