Chapter 6 provides information on finding your current location by using bearing, azimuth, back azimuths, a compass, and a map. It describes techniques for correcting for declination and explains intersection, resection, latitude, and longitude. Additional information highlights Global Positioning Systems (GPS), base, townships, range, and sections.

The perimeter is the distance around the fire or along the handline. Perimeter is determined by adding the lengths of the various lines that enclose the black area of a fire. Because fires often burned in unusual shapes such as fingers, the perimeter of a fire can be approximated by assembling a combination of known shapes and lines. 

The material in Chapter 5 describes calculating area and perimeter of a burn, fire spread distance, and effective windspeed. Detailed descriptions are provided for reading and using a map scale, converting map to ground distances, and using topographic maps.

Flame height is the average height of flames as measured vertically, up and down. It may be less than flame length if the flames are angled in the horizontal direction, backward or forward. 
 

Flame length is the distance measured from the average flame tip to the middle of the flaming zone at the base of the fire. It is measured on a slant when the flames are tilted due to effects of wind and slope. Flame length is an indicator of fireline intensity.

The material in Chapter 4 describes estimates of flame length, flame height, angles, degrees, and slopes. Reading clinometers and graphs and pacing out a chain are also covered.

Volume is used to indicate the capacity of a tank or container. It is used by firefighters to answer questions like "How much water is left in the tank?" and "At 15 gallons per minute (gpm), how many more minutes before the tank is empty?" 

VOLUME OF A RECTANGULAR OBJECT

The volume of a rectangular container is determined by multiplying the length (l) by the width (w) by the height (h).

The material in Chapter 3 describes aspects related to using water in wildland firefighting. These concepts include determining the weight of water, a description of factors related to friction loss, a review of basic drafting guidelines, as well as calculations related to volume, pump pressure, and flow rate. The chapter also provides instructions for estimating different parameters in the field, as well as a round-off table for ease of use.

UNIT CONVERSION AND CONVERSION FACTORS

A unit conversion expresses the same property as a different unit of measurement. For instance, time can be expressed in minutes instead of hours, while distance can be converted from miles to kilometers, or feet, or any other measure of length. Often measurements are given in one set of units, such as feet, but are needed in different units, such as chains. A conversion factor is a numeric expression that enables feet to be changed to chains as an equal exchange. 

INTRODUCTION

Chapter 2 provides information about converting units of measure, using known relationships called conversion factors. 

In completing this chapter, you'll learn how to set up a unit cancellation table and complete common unit conversion operations. The chapter also contains tables of typical units used by the wildland fire community.