Turbidity of Rain
(How dirty is the
During the month of March we
collected rain water samples to test the turbidity. On March 21, 2002
we met with Robert Bourke from Oceanit
and made Turbidity meters, created a standard turbidity substance and
tested our water samples. We sorted our samples by time and date then
ranked the bottles from cleanest to dirtiest (see chart).
How to make a Turbidity
1. Get a 3 feet long
plexiglass tube and mark lines up the tube every 10
2. Place a cork in the bottom to keep the water from falling
3. Fill with rain water
4. Drop a 1 inch long metal nut with a happy face sticker on
it into the tube. It will drop to the bottom.
5. Using a magnet on the outside of the tube, raise the nut
with the happy face on it until you can see the face clearly
looking down from the top of the tube.
6. Record the measurement
How to make a Standard Turbidity Substance:
1. Measure 1/2 teaspoon
of white Pilsbury Flour
2. Mix with 2 liters of clean fresh water
3. Dilute by half (mix 1 liter of mixture with 1 liter of
clean fresh water
4. Dilute by half again (mix 1 liter of new mixture with 1
liter of clean fresh water)
5. Repeat "Dilute by half" 3 more times
6. Pour mixture into your Turbidity meter and test.
7. Use this subtance if rain water meatures "0" in your