OBS501 Smart Turbidity Meter with ClearSensor
®
Technology
5
6.
If
LoggerNet
,
PC400
, or
PC200W
is running on your PC and the PC to
datalogger connection is active, click
Finish
in
Short Cut
and you will be
prompted to send the program just created to the datalogger.
7.
If the sensor is connected to the datalogger, as shown in the wiring
diagram in step 4, check the output of the sensor in the datalogger support
software data display to make sure it is making reasonable measurements.
5. Overview
5.1 Applications
Turbidity sensors are used for a wide variety of monitoring tasks in riverine,
oceanic, laboratory, and industrial settings. They can be integrated in water-
quality monitoring systems, CTDs, laboratory instrumentation, and sediment-
transport monitors. The electronics of the OBS501 are housed in a Delrin
®
package, which is ideal for salt water or other harsh environments.
Applications include:
•
Compliance with permits, water-quality guidelines, and regulations
•
Determination of transport and fate of particles and associated
contaminants in aquatic systems
•
Conservation, protection, and restoration of surface waters
•
Assess the effect of land-use management on water quality
•
Monitor waterside construction, mining, and dredging operations
•
Characterization of wastewater and energy-production effluents
•
Tracking water-well completion including development and use
5.2 Backscatter and Sidescatter Sensors
The heart of the OBS501
sensor is a near-infrared (NIR) laser and two
photodiodes for detecting the intensity of light scattered from suspended
particles in water. One detector measures the backscatter energy and the second
is positioned at 90 degrees to the emitter to measure the sidescatter energy.
Backscatter and sidescatter sensors have unique strengths and weaknesses.
Generally speaking, backscatter provides high-range (HR) measurements, and
sidescatter provides low-range (LR) measurements. The OBS501 combines
both in one sensor to provide unequalled performance in a field turbidity
sensor. With their unique optical design (U.S. Patent 4841157), backscatter
sensors perform better than most in situ turbidity monitors in the following
ways:
•
Measure turbidity to 4000 TU (compared to 1200 TU typically for
sidescatter sensors)
•
Insensitivity to bubbles and organic matter
•
Ambient-light rejection
•
Low temperature coefficient
Sidescatter sensors have the following advantages:
•
More accurate in very clean water
•
Fixed measurement volume
