Campbell OBS500, Руководство оператора

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OBS500 Smart Turbidity Meter with ClearSensor
®
Technology
30
1. Run the OBS500 in a normally open mode. For example, close then open
the wiper once every four hours. This reduces the wear on the motor
significantly, and save power. The interval can be adjusted over time.
Increase the interval if experiencing fouling. If the windows are staying
clean, slow it down even more. Example CRBasic programs are provided
at Appendix B.4 , Examples for High Sediment Loads
(p. B-4)
.
a. M3! opens the wiper
b. M4! , M5! , or M6! perform measurements when the wiper is open
c. M7! closes the wiper
2. Clean the shutter assembly. The frequency that the shutter should be
cleaned depends on the sediment load and can vary from weeks to months
(step 3 can help you determine the required frequency for cleaning). Two
levels of cleaning should be done;
a. flush the wiper as it opens and closes with a stream of clean water, or
b. remove the wiper from the OBS500 by removing one screw and
follow the directions provided in Section 7.7.1 , Wiper Removal
Procedure
(p. 30)
. Flush and clean.
3. Store the current used to open and close the slider. The open and close
SDI-12 instructions (M3! and M7!) output the current. Normally the
current is around 100 mA. As sand grits lodge in the groves, the resistance
to movement increases and the motor has to work harder. This increases
the current usage. Therefore, increased current usage indicates that the
wiper needs to be cleaned (see step 2).
4. Mount the sensor between 45 degrees pointing down to vertical hanging
down.
7.7.1 Wiper Removal Procedure
1. Remove the stop screw in the OBS500 housing at the end of the
shutter/wiper slot.
2. Remove the 4-40 flat head screw and copper plate to expose the drive shaft
access port (FIGURE 7-9 ).
3. Insert a slot screw driver (2.5 mm (0.1 in.) wide blade) into the access port
(FIGURE 7-10 ).
4. Engage the end of the drive shaft and then rotate clockwise until the
shutter is free (FIGURE 7-10 and FIGURE 7-11 ).
Keep track of all of the components (FIGURE 7-12 ).
5. Reassemble by reversing the steps.
CAUTION