The hardware setup is the same as shown in the previous post. The experiment to test
the functionality of the monitoring system is set up by placing the sensors in
the water. The sensors are tested using a water that is simulated to the one
used in the catfish tank except for the chlorine content in the water is not
filtered but it will not affect the reading produced by the sensors. The
temperature sensor is tested by adding a slightly hot and cold water into the
container used to hold the water which also will affect the amount of dissolved
oxygen and the pH value of the water. This is because more dissolved oxygen
present in the cold water than warm and the pH measurement varies in different
temperature. The normal condition for the pH measurement is at 25 ⁰C at where the pH value varies at ±0.001 pH in a temperature other than 25 ⁰C.
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The changes in water temperature |
The graph rises a bit when a little hot water
is added before it goes back to a constant reading. When a
slightly cold water is added, the water temperature drops from 30.31°C to 28.43°C. The changes in the water temperature is not obvious as shows
in the graph for the insignificant drops of 1.88°C.
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Changes in pH value of the water |
The pH value turns from neutral state into acidic and alkaline state when the pH solution of 4.00 (acidic) and 9.18 (alkaline) is added to it.the colour changes from green which indicates normal condition into red colour which indicates a warning sign when the water quality is in a bad condition.
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Dissolved oxygen value |
From the beginning until the end, the
sensor produced a reading 0 mg/L for the content of the dissolved oxygen. This condition
means that there is no oxygen at all in the water which makes the water not
suitable to be used for the catfish or any other living creature to live in. it is possible for the water to possess no
oxygen at all since I’m using tap water which normally possess 10 mg/L of the
dissolved oxygen content in it. The voltage output from the sensor is not zero
when measured using the multimeter, which means that there is oxygen detected
by the sensors since the content of the dissolved oxygen in the water is
directly proportional to the voltage output from the probe. The connection and coding
of the dissolved oxygen sensor needs to be revised according to the datasheet
provided on the manufacturer’s website.