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Make sure that all the valves and connections required to run your experiment are made. Your stamp box should look something like the figure below.
(insert picture of stamp box)
Step Two: Start the Experiment
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You only need to complete one full cycle of data collection. The next step is to to open the datalog and statelog that contains your file. Using the file directory where you logged your data i.e. N:\Courses\AguaClara\FlocTube fall09, open the excel file datalog and the statelog for the date of your experimentation.
Data Analysis in Excel
For this experiment we wish to plot the water level height in the tank over one cycle of the experiment (measured in elapsed time). Your first task is to create a graph of water level height in the tank over one tank cycle.
Follow standard format conventions:
- Do not include a title. If you want to describe the graph, put a caption underneath and begin the caption with "Figure 1." for example.
- Label your axes and put the units in parentheses.
- Eliminate any grid lines unless you are in log mode.
Step Four: Using the State Log
Ensure that in your state log that you have cycled through the necessary states in process controller. There will be a time stamp of your team having done this.
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In looking at the sample state log, you should notice that the state log will also tell you how the state was changed. Under "Rule that caused the previous state to change," if the label is the next state in sequence then it means that Process Controller software changed the state. If the label was instead "Operator changed the state," that indicates that someone manually changed the state and overrided overridded Process Controller's automatic control.
Data Log
Below is a sample data log in excel. For this experiment we wish to plot the water level height in the tank over one cycle of the experiment (measured in elapsed time), and so we need to think about the important variables to graph in the data log. Pressure as measured by the pressure sensor is highlighted in yellow is "7 kPa" and the time that elapsed is highlighted in red as the "Day fraction since midnight on 9/4/2009" and this is shown in the figure below.
Now that we have identified the variables that we will plot, we need to find the range of time period over which we can plot these values on a graph.
Data Analysis in Excel
Your task is to create a graph of water level height in the tank over one tank cycle. You need to look up the time period for one complete time cycle (i.e. process controller cycled through "Add Chemical," "Settle," and "Drain."
When you have selected the data, convert your time data either into seconds or minutes. Also, set the time to be zero when you started the experiment.
In creating your graph, follow standard format conventions:
- Do not include a title. If you want to describe the graph, put a caption underneath and begin the caption with "Figure 1." for example.
- Label your axes and put the units in parentheses.
- Eliminate any grid lines unless you are in log mode.
An example graph is shown in the figure below. Do not worry if your graph does not have exactly the same values, but it should be close. This tutorial was an exercise of comprehension, not scientific precision.
