Elenco Snaptricity&reg - Manual (Page 81)

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Water Impurity Detector Project #71
1mA
If you want to watch
this for a while without holding it,
place the electrode between two
2-snaps as shown here.
The water in some areas is slightly acidic due to
impurities in it. This may be strong enough to produce
a current by reacting with the electrodes, similar to
how a battery works. These impurities should be safe
to drink.
Some fruit juices are more acidic and will produce a
higher current.
Description
Read the current on the meter, if it is zero then your
water is relatively free of impurities. Having impurities
does not mean your water is unsafe to drink. You can
try dissolving salt in the water and see if the current
changes.
If you have some distilled water, test it. It should have
zero current.
Replace the water with fruit juices and see how they
compare. Sour tasting juices like lemon or grapefruit
juice usually produce the most current.
Don’t drink any water or juice used in this project.
Wash any juice off the electrodes.
Operation
Set the meter (M5) to the 1mA scale and connect the
jumper wires to it. Hold the metal snap of the jumper
wires to the electrodes (red to copper), and place them
in a cup of water.
Assembly