A measure of the solid materials dissolved in the river water. This includes salts, some organic materials, and a wide range of other things from nutrients to toxic materials.
*Before you start, be sure that your conductivity meter is calibrated. This will be done when you get them, but it is a good idea to check them every so often. You can use a standardized solution sold for this purpose, or you can make a standard up yourself. To calibrate your meter, first insure that the reading is 0 ppm when the meter is inserted in deionized water. Then use the standard solution or dissolve thoroughly 200 ml of NaCl in 1 liter of water. Insert your conductivity meter and adjust it until it reads 300 ppm. Most meters have a small screw that can be adjusted with a very small screwdriver.
1. To use your conductivity meter, first soak the meter in alcohol to insure that the electrodes are clean. Insert the conductivity meter into the river water. Turn it on. Read the dial. Some meters need to have the reading multiplied by 10. The conductivity meter provides is a direct estimate of the total dissolved solids in mg/l.
2. BE SURE THAT THE UNIT IS TURNED OFF WHEN YOU RETURN IT TO ITS BOX. It is battery powered, and batteries run low. ALWAYS TEST YOUR METER TO INSURE THAT IT IS WORKING BEFORE YOU GO INTO THE FIELD. When the batteries run low, you are responsible for replacing them.
Call the street department, and ask what they use to melt snow. See if they use too much.
*CAN YOU THINK OF ANYTHING ELSE THAT WILL IMPROVE THE TDS CONCENTRATION IN THE RIVER AT YOUR STATION?
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