Campbell Scientific OBS-5+ Sediment Concentration Monitor and Pressure Sensor - Manual (Page 37)

OBS-5+ System
FIGURE 7-5. OBS-5+ in 100 mm cup
6) Add enough 250-NTU standard to cover the sensor end (FIGURE 4-1) and
swipe bubbles off the sapphire windows with your finger. Click the
Record button.
7) Repeat Step 6 for the 500 and 1,000 NTU standards.
8) Review the data table and graph, and if they look satisfactory, click the
Calculate Fit button.
9) Verify that the fit curve passes through the calibration points and that the
residuals are less than 10 NTU. Then click the Done button.
8. Troubleshooting
This section will help isolate problems that can be easily fixed, such as cable-
continuity, processor reset, and battery replacement, or more serious ones, such
as sensor, computer and electronic malfunctions, and damaged mechanical
parts that will require assistance. The problem symptoms are shown in bold
text.
Power failed because of contact corrosion or a broken power wire.
Check for a broken red wire connecting the battery tube and circuit board.
Green powder or tarnish on the battery contact parts indicates salt-water
corrosion. Remove the electronics by removing the set screws from the sensor
endcap and sliding it out of the pressure housing. Pull battery-contact-retainer
pin out with needle-nose pliers and slide the contact from its track. Clean the
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