Page 24 - Handbook of Energy Engineering Calculations

Learning SI. An efficient way for the USCS-conversant engineer to learn SI
follows these steps:

1. List the units of measurement commonly used in your daily work.

2. Insert, opposite each USCS unit, the usual SI unit used; Table 1 shows a
variety of commonly used quantities and the corresponding SI units.

3. Find, from a table of conversion factors, such as Table 2, the value to use

to convert the USCS unit to SI, and insert it in your list. (Most engineers
prefer a conversion factor that can be used as a multiplier of the USCS unit
to give the SI unit.)

4. Apply the conversion factors whenever you have an opportunity. Think in

terms of SI when you encounter a USCS unit.

5. Recognize—here and now—that the most difficult aspect of SI is
becoming comfortable with the names and magnitude of the units.
Numerical conversion is simple, once you’ve set up your own conversion
table. So think pascal whenever you encounter pounds per square inch

pressure, newton whenever you deal with a force in pounds, etc.

SI Table for an Energy Engineer. Let’s say you’re an energy engineer and
you wish to construct a conversion table for yourself. List the units you
commonly meet in your daily work; Table 1 is the list compiled by one

energy engineer. Next, list the SI unit equivalent for the USCS unit. Obtain
the equivalent from Table 2. Then, using Table 2 again, insert the conversion
multiplier in Table 1.

TABLE 1 Commonly Used USCS and SI Units *