Campbell OBS-3A Manual

OBS-3A Turbidity and Temperature Monitoring SystemRevision: 7/13Copyright © 2007-2013Campbell Scientific, Inc.

OBS-3A Turbidity and Temperature Monitoring System 3.1 Ships With CSI pn 21229 Accessory Kit ResourceDVD CSI pn 29225 HydroSci Software on DVD 4. Ov

OBS-3A Turbidity and Temperature Monitoring System FIGURE 4-1. Anatomy of an OBS sensor 4.2 Temperature and Optional Sensors Temperature is measure

OBS-3A Turbidity and Temperature Monitoring System Light transmission in water is attenuated by scattering (deflection by water molecules, and suspend

OBS-3A Turbidity and Temperature Monitoring System 5.1 Measurement Range Turbidity (AMCO Clear): 0.4 to 4,000 NTU1 Mud (D50=20 µm): 0.4 to 5,000 mg/

OBS-3A Turbidity and Temperature Monitoring System Battery capacity: 18 A h Maximum battery life: 8,000 hours Data protocols: RS-232 / RS-485 Maximu

OBS-3A Turbidity and Temperature Monitoring System TABLE 6-1. Working and Maximum Depths Pressure Sensor Working Depth Maximum Depth 0.2 Bar 0 to

OBS-3A Turbidity and Temperature Monitoring System the cable grip and connector and put chafe protection on the sensor head where it contacts the wire

OBS-3A Turbidity and Temperature Monitoring System FIGURE 6-2. Battery installation For extended deployment time, lithium batteries are a good alter

OBS-3A Turbidity and Temperature Monitoring System 6.3 Running HydroSci 1. Select the HydroSci program to start the program. 2. Physically connect

OBS-3A Turbidity and Temperature Monitoring System 3. Select OBS-3A on the lift side of the screen and select the appropriate COM Port and Baud Rate

OBS-3A Turbidity and Temperature Monitoring System 7. After you have finished interacting with your sensor, click on the Connection tab and press the

OBS-3A Turbidity and Temperature Monitoring System Blow on the temperature sensor to observe an increase in temperature (red trace line on the top plo

OBS-3A Turbidity and Temperature Monitoring System Show Terminal tab brings up a terminal screen that allows you to view the commands being sent to th

OBS-3A Turbidity and Temperature Monitoring System 6.8.2 Operations Put OBS-3A to Sleep Press the Sleep button to put the OBS-3A in low-power, slee

OBS-3A Turbidity and Temperature Monitoring System HydroSci will confirm if you want to put the OBS-3A to sleep. Clear OBS-3A Data Storage Press the

OBS-3A Turbidity and Temperature Monitoring System Barometric Correction The OBS-3A measures absolute pressure so a correction must be made for barome

OBS-3A Turbidity and Temperature Monitoring System Change to RS-232 To switch from RS-485 communication to RS-232 communication, press the RS-232 butt

OBS-3A Turbidity and Temperature Monitoring System If it becomes necessary to load coefficients from a saved file, press the Load Coefficients from Fi

OBS-3A Turbidity and Temperature Monitoring System Calibration The Calibration box can be used to calibrate the OBS-3A for NTU or mg/L measurements.

OBS-3A Turbidity and Temperature Monitoring System You will be asked whether or not you want to log data to a file on your computer. In survey mod

Warranty “PRODUCTS MANUFACTURED BY CAMPBELL SCIENTIFIC, INC. are warranted by Campbell Scientific, Inc. (“Campbell”) to be free from defects in materi

OBS-3A Turbidity and Temperature Monitoring System You can press the Load Configuration From File button to load a configuration that has previously

OBS-3A Turbidity and Temperature Monitoring System Units of Measure Select the units for depth (Meters or Feet). Sensor Measurements Select the check

OBS-3A Turbidity and Temperature Monitoring System You will be asked whether or not you want to log data to a file on your computer. After setting

OBS-3A Turbidity and Temperature Monitoring System • Wave Setup Wave Setup fields are only enabled when Depth is selected under Sensor Measurements a

OBS-3A Turbidity and Temperature Monitoring System o Rate Rate is the frequency of sampling for the duration of measurements. All sensors are samp

OBS-3A Turbidity and Temperature Monitoring System Go to the Connection tab and press Disconnect to disconnect from the OBS-3A. Unplug the test cabl

OBS-3A Turbidity and Temperature Monitoring System • Water Density Specify the water temperature and salinity. The specified temperature and salini

OBS-3A Turbidity and Temperature Monitoring System • Sample Settings o Duration This is the length of time in seconds that the OBS-3A is measuring

OBS-3A Turbidity and Temperature Monitoring System 6.8.6 Setpoint Configuration Setpoint Configuration mode is used for fast sampling of events such

OBS-3A Turbidity and Temperature Monitoring System • Sensor Measurements Select the check boxes next to the sensor measurements you wish to make. F

Assistance Products may not be returned without prior authorization. The following contact information is for US and international customers residing

OBS-3A Turbidity and Temperature Monitoring System • Interval Settings o Slow Interval The time, in seconds, between the start of one sample and t

OBS-3A Turbidity and Temperature Monitoring System Temperature, Salinity, Concentration, and Depth are shown on the charts. Only the sensor measureme

OBS-3A Turbidity and Temperature Monitoring System All sensor measurements selected in the configuration will be shown in the table view. Use the scr

OBS-3A Turbidity and Temperature Monitoring System 6.10 View Data The View Data screen can be used to view data stored on the OBS-3A from cyclic, sch

OBS-3A Turbidity and Temperature Monitoring System 3. A screen asking if the OBS-3A is currently sampling will appear. If you are ready to stop samp

OBS-3A Turbidity and Temperature Monitoring System 4. Go to View Data to save data in a file. 5. Highlight the data with the start and end times y

OBS-3A Turbidity and Temperature Monitoring System 6. Once the correct data is selected, press Save Data File. The Save As screen will appear, name

OBS-3A Turbidity and Temperature Monitoring System Then press the New Line Graph button and a new screen will appear with various graphing options.

OBS-3A Turbidity and Temperature Monitoring System . The spreadsheet of data can also be printed. 6.11 Show Terminal The Show Terminal tab brings u

OBS-3A Turbidity and Temperature Monitoring System 6.12 Shutdown From the OBS-3A Configuration | Operations tab, select Put OBS-3A To Sleep. It wi

Table of Contents PDF viewers: These page numbers refer to the printed version of this document. Use the PDF reader bookmarks tab for links to spec

OBS-3A Turbidity and Temperature Monitoring System 6.14 Erasing Memory Data To erase the memory data on the OBS-3A, go to OBS-3A Configuration | Op

OBS-3A Turbidity and Temperature Monitoring System 7. Calibration It is a good idea to use the Retrieve and Save Coefficients to File button (under

OBS-3A Turbidity and Temperature Monitoring System • 100 ml to deliver (TD) volumetric pipette • 25 ml TD measuring pipette • 2 gallons filtered di

OBS-3A Turbidity and Temperature Monitoring System 3. Prepare the next NTU standard and put the OBS-3A in it. Repeat steps 1 and 2 for all calibrati

OBS-3A Turbidity and Temperature Monitoring System The formula for preparing turbidity standards other than shown in TABLE 7-1 is: ⎥⎦⎤⎢⎣⎡+=stkdwstkstk

OBS-3A Turbidity and Temperature Monitoring System 7.2.1 Equipment and Materials • Dry, completely disaggregated bottom sediment or suspended matter

OBS-3A Turbidity and Temperature Monitoring System 10 20 30 40 50Sediment Concentration (mg/l)0102030405060Turbidity (NTU)Hand Shaking15-min. Sonic Ba

OBS-3A Turbidity and Temperature Monitoring System Sediment concentrations are calculated with the following equations: mg/lρMVMssis=⎥⎦⎤⎢⎣⎡+ ;

OBS-3A Turbidity and Temperature Monitoring System FIGURE 8-1. Component locations Unit does not communicate with PC. There are several possible c

OBS-3A Turbidity and Temperature Monitoring System b. If the OBS-3A still fails to respond, try changing baud rate speeds by selecting Attempt to f

Table of Contents 6.13 Excel Spreadsheets ... 41 6.14 Erasing Memory Data..

OBS-3A Turbidity and Temperature Monitoring System Power failed due to battery clip corrosion or a broken power wire. Check for a broken red wire conn

OBS-3A Turbidity and Temperature Monitoring System 9. Maintenance 9.1 OBS Sensor The OBS sensor must be kept clean to measure sediment concentration

OBS-3A Turbidity and Temperature Monitoring System during surveys or after each deployment. A sensor that has been stored dry should be soaked in wat

OBS-3A Turbidity and Temperature Monitoring System 9.5 Pressure Housing The pressure housing and O-ring seals require little maintenance unless the h

OBS-3A Turbidity and Temperature Monitoring System 10.1 Particle Size The size of suspended sediment particles typically ranges from about 0.2 to 500

OBS-3A Turbidity and Temperature Monitoring System 10.2 Suspensions with Mud and Sand As mentioned earlier, backscattering from particles is inversel

OBS-3A Turbidity and Temperature Monitoring System 10.3 High Sediment Concentrations At high sediment concentrations, particularly in suspensions of

OBS-3A Turbidity and Temperature Monitoring System 10.4 Sediment Color Sediment color, after particle size, has a major effect on OBS sensitivity, an

OBS-3A Turbidity and Temperature Monitoring System 10.6 Bubbles Although bubbles efficiently scatter IR, monitoring in most natural environments show

OBS-3A Turbidity and Temperature Monitoring System 10.7 Biological and Chemical Fouling Sensor cleaning is essential during extended deployments. In

Table of Contents Tables 6-1. Working and Maximum Depths...7 7-1. Mixing Volumes for Formazi

OBS-3A Turbidity and Temperature Monitoring System 62 Standard Methods for the Examination of Water and Wastewater, 20th Edition. 1998. 2130 Turbidity

Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com • info@campbel

Table of Contents iv

OBS-3A Turbidity and Temperature Monitoring System 1. Introduction The OBS-3A combines our OBS® probe with pressure, temperature, and conductivity s