Campbell Scientific OBS500 Smart Turbidity Meter with ClearSensor Technology - Manual (Page 18)

OBS500 Smart Turbidity Meter with ClearSensor™ Technology
6. After selecting the sensor, click at the left of the screen on Wiring
Diagram to see how the sensor is to be wired to the datalogger. The
wiring diagram can be printed out now or after more sensors are added.
7. Select any other sensors you have, then finish the remaining Short Cut
steps to complete the program. The remaining steps are outlined in Short
Cut Help, which is accessed by clicking on Help | Contents |
Programming Steps.
8. If LoggerNet, PC400, or PC200W is running on your PC, and the PC to
datalogger connection is active, you can click Finish in Short Cut and you
will be prompted to send the program just created to the datalogger.
9. If the sensor is connected to the datalogger, as shown in the wiring
diagram in step 6, check the output of the sensor in the datalogger support
software data display to make sure it is making reasonable measurements.
5. Overview
The heart of the OBS500 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 side scatter
energy.
Backscatter and side scatter sensors have unique strengths and weaknesses.
Generally speaking, backscatter provides high-range (HR) measurements, and
side scatter provides low-range (LR) measurements. The OBS500 combines
both in one sensor to provide unequalled performance in a field turbidity
sensor. With their unique optical design (U.S. Patent No. 4,841,157),
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
side scatter sensors)
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