This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 1 Linear interpolation 1.1 Description Linear interpolation is a way to fill in the “holes” in tables. As an example, if you want to find the saturated pressure of water at a temperature of 40 ◦ C you can look in Table B.1.1, (p.674), for 40 ◦ C in the first column. The corresponding desired pressure is then in the next column; in this case, 7.384 kPa. But what if you want to find the saturated pressure at 38 ◦ C instead of 40 ◦ C? A temperature of 38 ◦ C is not in the table. You could of course just ignore the difference between 38 ◦ C and 40 ◦ C, and still take the saturated pressure to be 7.384 kPa. But that is not acceptable in this class; it is too inaccurate. To get an accurate value, you must use linear interpolation. (Though taking the closest value, 40 ◦ C, is of course better than nothing in case you forgot how to do linear interpolation during an exam.) Let’s introduce a few symbols. Let g be your given value, 38 ◦ C in this example. Let g 1 and g 2 be the two closest approximations to g in the table. A look at Table B.1.1 shows that the two closest values you can find in the table are 35...
View
Full Document
 Spring '09
 Dommelen
 5.628 kPa, 7.384 kPa, 1.3 20 kPa, 6.682 kPa

Click to edit the document details