Campbell Scientific OBS-5+ Sediment Concentration Monitor and Pressure Sensor - Manual (Page 6)

Table of Contents
7. Calibration .................................................................20
7.1 Sediment and NTU Calibration ......................................................... 20
7.1.1 General Guidance....................................................................... 21
7.1.2 Equipment and Materials............................................................ 24
7.1.3 Procedure for Sediment .............................................................. 24
7.2 Turbidity (NTU) Calibration ............................................................. 28
7.2.1 Equipment and Materials............................................................ 28
7.2.2 Procedure for Turbidity.............................................................. 28
8. Troubleshooting........................................................29
9. Maintenance ..............................................................32
9.1 OBS-5+ Sensor.................................................................................. 32
9.2 Pressure Sensor.................................................................................. 32
9.3 Batteries............................................................................................. 33
9.4 Pressure Housing............................................................................... 33
9.5 User-Serviceable Parts....................................................................... 33
10. Interfering Factors ....................................................34
10.1 Particle Size....................................................................................... 34
10.2 NIR Reflectivity ................................................................................ 35
10.3 Particle Shape, Flocculation, and Disaggregation ............................. 36
11. References.................................................................38
Appendix
A. Turbidity Standards ................................................A-1
Figures
4-1. Dimensions (top), sensor endcap with copper antifoulant (Cu a.f.)
collars (left) and connector endcap (right) ....................................... 2
4-2. Schematic of optical system ................................................................ 3
4-3. Sample calibration curves (fine and bold lines), lookup tables I, II,
and III (bold curves), and sediment concentrations pf ND (open
arrow) and FD (solid arrow) peaks. ................................................. 4
4-4. Calibration curves for four different sediments and SSC values for
near-detector peaks (colored arrowheads). ...................................... 5
6-1. Electrical connections.......................................................................... 8
6-2. Battery installation: A) endcap removal, B) wiping, C) cable
disconnect, and D) battery contact................................................... 9
6-3. New data log prompt ......................................................................... 10
6-4. Designating your own file name and destination............................... 10
7-1. Manual (left) and automatic (right) sediment suspenders.................. 21
7-2. Lookup tables and table limits (a, b, and c)....................................... 22
7-3. OBS-5+ in big black tub of clean water ............................................ 25
7-4. OBS-5+ in suspender tub................................................................... 26
7-5. OBS-5+ in 100 mm cup..................................................................... 29
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