Figure 4-54.  Volume chamber. Figure 4-55.  Type 1 deployment in a pilot emergency rig. doing some kind of retro placcarding as the requirement did  not include force measurement. Fortunately, there are only  a small number of systems/components certified under this  rendition. Any component so certified would not be able to  be used as there are no guidelines for compatibility. An important criterion in determining compatibility is  the volume of the canopy. The canopy has to fit into the  container in such a manner as to not place undue stress on  the system when packing and to be extracted by the pilot  chute during deployment. The container manufacturer  usually provides a volume chart of their systems stating  what the volumes are for the various model sizes. Container  volumes are somewhat nonsequitur; however, as container  manufacturers derive their numbers in different ways. Some  container manufacturers do not publish numbers per se;  rather, they indicate a model designation that fits a size  range of canopies.  The canopy manufacturer should provide the volumes of  the canopy models. Measuring canopy volumes has proven  to be an imprecise science as there are various methods that  can be used. The most common method involves placing  the canopy in a tubular chamber and compressing it with  a standard amount of weight for a set time. The displaced  volume is then measured.  Figure 4-54  shows one such  volume chamber. Slight differences in volume can be seen  from chamber to chamber and canopy to canopy. These  variances occur due to humidity at the time the test is  conducted and due to variation in the bulk of the fabric that  the canopy was built with. For example, sometimes a 150  square foot reserve is 312 cubic inch and sometimes that  very same model, built using a different dye lot of fabric is  363 cubic inch. Canopy volume charts can be found on the  Parachute Industry Association (PIA) website at www.pia. com and the Parachute Labs website at www.jumpshack. com. While some canopy manufacturers disagree with  the resultant numbers, most container manufacturers and  riggers agree that these independent test methods are useful  in determining volume compatibility. In Chapter 2 of this handbook, Design and Construction,  the different types of canopy deployment devices were  described. In some instances, the container system needs  to be of a specific configuration to accommodate a certain  deployment device. An example of this would be where a  round canopy utilizing a Type 1 configuration is packed into  a pilot emergency parachute system. In this case, the pilot  chute is compressed directly onto the floor of the container  system.  [Figure 4-55]  This same canopy can be packed into  a sport reserve container, but the sport rig has two internal  or staging flaps that compress and hold the canopy in place  and are locked together by the bridle.  [Figure 4-56]  The pilot  chute is then packed on top of the internal flaps. The rigger  needs to know and understand these differences to determine  how the two components interface for compatibility. Deployment Type Volume 4-16