Matrix has an assortment of expansion factor tables available from which you may choose.

In most cases it is desirable to commit to using just one set of factors as the only real value of the calculated Coefficient of Expansion for glazes is the ability to compare one glaze with another and to determine whether you are making appropriate changes when tackling the task of controlling crazing (glaze fit).

Some practitioners however prefer one set of factors over others.

Alternative Expansion Tables

Matrix offers the following sets of Expansion Coefficient Tables:

• Appen
• English & Turner
• West & Gerrow
• Winkelmann & Schott
• Bailey_C6 Expansions

The default table which Matrix uses is Winkelmann & Schott.exp

Changing the Default Expansion Table

To command Matrix to use a different set of expansion factors each time it boots

• select the Options (Preferences) item in the Matrix menu.
• click Coef. of Expansion File Path the tab.
• click on the button and locate the Expansions file you wish to use. Expansion files have the extension (.exp) and they should all be in the Expansions folder.

Viewing the Currently Loaded Expansion Factors Table

The oxide factors contained in the expansion table currently being used by Matrix may be viewed by selecting the Oxide Expansions ... item in the View menu or clicking the button on the Tool Bar.(Fig.1)

Fig.1 Oxide Expansions Window

The Oxide Expansions window (Fig.1) shows the name of the set of factors being used and lists the individual oxide expansion values together with a bar graph showing the expansion factors in relation to the KNO (K2O + Na2O) value expressed as 100. This graph is useful when deciding what alterations to make to a seger formula when attempting to controlling crazing. Changing to a New Set of Factors To load a new set of expansion factors from disc select the Edit Expansion Factors item in the Action menu of Oxide Expansions Window. The Windows file selector opens (Fig.2) in the Expansions folder where you can select another set of factors.

Fig.2 Loading a Different se of Expansion Factors.

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