======Propellant Window======
{{ en:media::inputfield-propellant.png?25%&link}}

The data provided contains all necessary values to describe the characteristics of a given propellant. All fields are editable, but it is highly recommended to refrain from doing so.

**The propellant window contains the following fields:**

  * **Propellant (Powder) Selection (first drop-down)**\\ By selecting a powder from the propellants database, all values ar set to manufacturers standards. 

  * **Spec. Explosive Heat (Qex)**\\ This value (Qex) describes the total contained amount of explosive energy of the powder taken by caliometric measurements. 

  * **Isotropic Exponent (k)**\\ This value (κ) describes the heat-capacity of gases created by the powder at constant pressure (Cp) and volume (Cv)

  * **Combution Coefficient (Ba)**\\ This value (Ba) describes the "vitality" of the powder during the ignition process.

  * **prog./degr. Coefficient (a0)**\\ This value (a0) is a reference, whether the powder reacts progressive or degressive when combusted.

  * **Transition Limit (z1)**\\ This value (z1) is the boundary, where the powders progressive combustion translates into __primary-degressive__ combustion.

  * **Transition Limit (z2)**\\ This value (z2) is the boundary, where the powders __primary-degressive__ combustion translates into __secondary-degressive__ combustion

  * **Material Density (Pc)**\\ The density of material (pc) describes the mass/density of the material, the powder is made from.

  * **Bulk Density (Pcd)**\\ Bulk density (pcd) describes the mass/density of the powder, in its final physicall appearance per volume (including air pockets in cavities and between flakes or filaments)

  * **Powder Temperature (Pt)**\\ The temperature of the propellant. This temperature has some influence of the combustion behaviour of the propellant itself.

  * **Powder Mass (mc)**\\ The amount of powder dispensed into a case/round. This is the central editable field to explore changes in pressure, velocity and muzzle energy in the output diagrams to aquire a suitable charge.

  * **Loading Ladder**\\ This field is used to tell GRT, if multiple graphs for pressure, velocity and energy should be used in the main output diagram as a load development ladder. If no stepping (=1) is applied selected, only single graphs (corresponding to the selected powder mass) for pressure, energy and velocity will be drawn. If stepping (n>1) is applied, multiple graphs are generated. Those reflect the maximum charge, based on the selected powder mass and additional n graphs for n times reduced amounts of powder (see step size). 

  * **Step Size**\\ This defines the offset for the reduced charges in load development ladder mode