Creating a percent finer graph (also known as a particle size distribution graph or a grading curve) in Excel is straightforward once you understand the data required and the steps involved. This type of graph is crucial in various fields, including geology, materials science, and manufacturing, to visualize the distribution of particle sizes within a sample. This guide will walk you through the process, step-by-step.
Understanding Your Data
Before you begin, ensure you have the necessary data. You'll need two columns:
- Particle Size (x-axis): This represents the size of the particles in your sample (e.g., microns, millimeters). List your sizes in ascending order. It's important to use consistent units throughout your data.
- Percent Finer (y-axis): This indicates the percentage of particles in the sample that are finer (smaller) than the corresponding particle size in the first column. This is usually obtained from sieve analysis or other particle size measurement techniques.
Example Data:
| Particle Size (microns) | Percent Finer |
|---|---|
| 10 | 98 |
| 20 | 90 |
| 50 | 75 |
| 100 | 50 |
| 200 | 25 |
| 500 | 5 |
| 1000 | 1 |
Creating the Percent Finer Graph in Excel
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Input Your Data: Open a new Excel spreadsheet and enter your particle size and percent finer data into two adjacent columns.
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Select Your Data: Highlight both columns, including the headers (Particle Size and Percent Finer).
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Insert a Chart: Go to the "Insert" tab and choose the "Scatter" chart type. Select the option that shows data points connected by lines (usually the first option under "Scatter").
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Customize Your Chart:
- Chart Title: Add a descriptive title, such as "Particle Size Distribution".
- Axis Labels: Clearly label your x-axis ("Particle Size (microns)") and y-axis ("Percent Finer"). This is crucial for clarity and understanding.
- Data Points: Ensure your data points are clearly visible. You might need to adjust the marker size or style.
- Gridlines: Adding major and minor gridlines can enhance readability, especially for detailed analysis. You can find these options under "Chart Elements" within the chart design menu.
- Scaling: Check the scaling of your axes. Excel might automatically adjust the scale, but you might need to manually refine it to ensure optimal visualization of your data.
Interpreting Your Percent Finer Graph
The resulting graph will show the cumulative percentage of particles finer than a given size. A steeper curve indicates a narrower particle size distribution, while a flatter curve represents a wider distribution. You can use this graph to easily identify key percentiles, such as the D10, D50 (median), and D90 values which represent the particle sizes at which 10%, 50%, and 90% of the sample is finer, respectively. These percentiles are often used to characterize the overall particle size distribution.
Tips for a Professional-Looking Graph
- Consistent Units: Maintain consistency in units throughout your data and labels.
- Font and Colors: Use a clear, professional font and choose colors that are easy to read and distinguish.
- Legend (If Needed): If you have multiple datasets, use a legend to clearly identify them.
- Save as Image: Once you have a polished graph, save it as a high-resolution image (PNG or JPG) for use in reports and presentations.
By following these steps, you can easily create informative and professional-looking percent finer graphs in Excel to effectively visualize particle size distributions. Remember to carefully review and adjust the graph's elements to best represent your data and meet your communication needs.
