Measuring with the Rubber-Thread Ozonometer
Making Measurements
1. Place rubber thread on the ozonometer and adjust the pointer to
zero (0) degrees.
2. Place the ozonometer at the measuring site and cover it with the
sun-wind cover.
3. After ten (10) minutes, record the pointers position. This
position will be the start position of the measurement, which
begins now. This point in time is also the start time of your
measurement.
4. Exactly one (1) hour after the start time, record the pointers
end position and the end time.
5. As noted to the left, if the pointer has moved less than 10
degrees, continue your measurement. You can extend the
measurement time up to four hours. Record the pointers new end
position and the new end time.
6. Calculate the concentration of ozone by finding your Pointer
Movement (divided by the duration in hours if more than one hour)
on the table on the ozonometer, or by using the formula below. See
the Global Lab Toolkit for more information. Record your experiment
data below.
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Measurement Start Time Start Position
End Time End Position
Measurement Duration
End time - Start Time
Pointer Movement (in degrees)
End Position - Start Position
Pointer Rate (in degrees per minute)
Pointer Movement / Measurement Duration
Ozone Concentration (in ppb)
Pointer Rate * 300