Common Problems and Troubleshooting
Problems with tubing and connectors
1. When the connections of tubes are leaking, you should check the tubes to make sure they are fully plugged into the connectors-- the tube can not be easily pulled out if it is fully inserted. To ensure no leaking, you need to verify each connection is robust before beginning the experiment. If there is a leak at the top of the settling column, stop any experiment and drain the column. You may need to remove the turbidimeter to adjust the connection.
Problems with apparatus
1. If the apparatus is not on when you turn on the switch, that is because the power strip sometimes trips the GFI protection. When you meet this problem, press the GFI reset button which is on the outlet behind the water tank (close to the tap).
2. If the alum pump is not running at loading state, first ask yourself if this is the first cycle. If it is the first cycle, then this is normal because the alum dose is reset to be zero at the first cycle. If it's not the first cycle, go to settling state and then click loading state to see if the alum dose has an increment. If there is an increment, then the valve (between the rapid mixer and raw water pump) may be mistakenly closed. If it is not, then check if the set points are set correctly by locating the set points at rule editor to ensure the variables match the required code.
3. If the pump is running in the opposite direction, check the states on Process Controller to see if pump cw/ccw is set correctly-- the "ON" state means clock-wise and "OFF" state means counter clock-wise.
4. If influent turbidity is too high (meaning it is at least 10 NTU more than the target turbidity max), use a 1L plastic container to scoop up some water from the raw water bucket. This water will be replaced by clean tap water to keep the volume constant and you should seethe turbidity go down. The influent turbidity should decrease by at least 15 NTU after you remove 1L of dirty water. The water in the raw water bucket gets dirtier and dirtier with clay addition. It is hard to insert another tube to drain the water so water that is too turbid must be removed manually before an experiment is started.
5. If the influent turbidity is lower than at least 10 NTU of your target turbidity max, then it's mostly likely that clay is not added into the raw water. The small tube transporting clay may be clogged or the valve controls clay addition is not working or there is not enough clay solution in the clay stock bucket. Tube clogging can be solved by "tubing massage" or placing a thin stick into the tube or replacing with a new tube. If the valve is not functioning well, you need to test the valve to see if it is the "tumidity on-off control" set point is set correctly. For the case clay solution is running out, prepare 10 L distilled water with 100g clay.
6. If water is filling up the flow accumulator, check the cap of the accumulator to make sure it's tight.
Problems with Process Controller
1. If you turn on all the switches, and none of the green indicator lights on Process Controller are on, that means you are not connecting with the right server or the server may have crashed. Check the main server to make sure it is functioning properly and check the data server on Process Controller (should be "aguadata.cee.cornell.edu").
2. When you're operating from one state, sometimes nothing is shown on the "current state" and the "state list" is not shown at "rules and states" at the next state. When this happens you need to reload the method file and save it in your experiment folder.
3. Sometimes this computer automatically disconnects with the AguaClara file server. Then you need to map the network again. If that doesn't help, you may need to restart the computer and map the network with AguaClara server.
Problems with Data Processor
1. If you're having trouble loading the data from Metafile of Data Processor, first you need to check the directory to make sure it's on the right track to locate the Metafile (an excel spreadsheet in the "data processor" folder). Second check all of the information for a certain MetID (the one correlates with your experiment) to make sure it's correct. Pay attention to the dates and duration (if your experiments span 2 days, you need to put in the both dates and a duration of 2.
2. Sometimes the graph on the MathCAD file of Date Processor is not shown due to memory loss, then you may have to restart the computer to reload the data or use another computer.