The temperature on a very cold day in Moscow in February is -27 C. The answer can be expressed as 1,340 MW or 1.34 GW. To avoid use of trailing 0's or powers of 10, use the SI prefixes in Table 2. What is the total capacity of the 1,500 stations? First, convert the 1,200 hp to kW using the factor of 0.7457 (from Power category), yielding 895 kW (1,200 x 0.7457). Example 4Ī utility company decides to promote distributed generation by building 1,500 ministations with each powered by a 1,200 hp diesel engine. The BTU/Hr rating of the propane furnace to be equivalent to the electric heating system is 85,300 BTU/Hr (25 x 3,412). Then under the BTU/Hr column, find the multiplier of 3,412. What BTU/Hr rating of propane furnace is needed for the same heating capacity? Under the Power category in Table 1, locate the numeral '1' under the kW column. Example 3Īn electric resistance heating system rated at 25 kW is to be replaced with a propane furnace. The energy density of the buckwheat as 6,664 BTU/lb (15.5 x 429.922). Locate the numeral '1' under that column and then read to the left to get the multiplication factor of 429.922 under the BTU/pound column. What is the energy density in units of BTU/lb? Go to the category of Energy Density in Table 1 and find the column for MJ/kg. Example 2Įnergy content of buckwheat is 15.5 MJ/kg (Mega Joules per kilogram). Then calculate the number of square feet as 64,583 (0.60 x 107,639). Find the numeral '1' under hectare column and read the multiplier of 107,639 on the same line to the left under sq ft column. For another exercise involving area, calculate how many sq ft (square feet) are in a plot that is 0.6 hectare. The area of the 160 acre field in hectares is 64.8 hectares (160 x 0.4047). Follow that line to the right to find the corresponding multiplication factor of 0.4047 under the hectare column. Since the known unit is 'Acres', find the numeral '1' under the acre column. Equations for Temperature Conversionsį = degrees Fahrenheit C = degrees Celcius R = degrees Rankine K = degrees Kelvin Δt = temperature difference Examples Illustrating the Use of the Conversion Factors Example 1Ī field is 160 acres and you want to express that area in hectares.

The equations for converting temperatures and temperature differences from one system to another are presented in Table 3. No single conversion factor can be used to convert temperatures in the English system (degrees Fahrenheit or degrees Rankine) to temperatures in the SI system (degrees Celsius and degrees Kelvin) or the other way around. Use of these prefixes avoids the need for powers of 10 notations. SI prefixes indicating orders of magnitude are provided in Table 2. Additional conversion factors are presented for energy, energy density, and energy yields. Table 1 presents the conversion multiplication factors to convert from English units to SI units (and vice versa) for basic measurements including length, weight, area, volume, bulk density, mass flow rate, volume flow rate, pressure and power. The fact sheet is intended for use in the classroom as well as for extension outreach programs. This fact sheet is intended to serve as a reference for converting many different types of measurements quickly and accurately from one system of units to another.

The conversion factors presented are for general measurements as well as those primarily associated with energy calculations additional conversion multipliers can be found in the the references. Unit conversion multipliers are presented in this fact sheet along with several examples to describe the use of these multipliers. There have been some very costly failures associated with insufficient attention being given to the units of measurements involved in calculations and communications.Ī methodical approach is needed to avoid errors encountered when converting from one system of units to another. World-wide communications, commerce, finance and many other functions depend upon everyone involved in the processes to be knowledgeable of both systems of measurements. As our society and economy become more global in scope, it is increasingly important to fully comprehend both the English and the SI systems of units and to accurately and conveniently convert from one system to another.

The SI system of units (often referred to as the metric system) is the official system for measurements in nearly all countries of the world, but not in the U.S. Today it is very important to be able to understand measurements in both the English system of units and the SI (Systems International) system of units.

Scientific unit conversion