This section contains one large table and one large graph field. The section displays the values (tabularly and graphically) of physical properties dependent upon both temperature and pressure.

1	Property Control: this control shows the property whose values are currently displayed in the section's table and graph controls.
2	Type Control: this control shows what type of values are currently displayed in the section's table and graph controls. The different types of values are: curve points, data values, equations, and estimates.
3	Table Control: displays the selected physical property's values. A green triangle in the table control's upper right corner indicates that additional data are available. (See below.)
4	Graph Control: displays the selected physical property's data values, estimated values, and curve points.

Note that the table control contains several additional controls enabling you to select units for the temperature and property values.

5	Temperature Units Control: this control shows the units in which temperature values are displayed.
6	Pressure Units Control: this control shows the units in which pressure values are displayed.
7	Property Value Units Control: this control shows the units in which property values are displayed.

1	Properties List Control: Displays all temperature and pressure dependent physical properties.
2	Values Type List Control: Displays the type of values available in this section.

Selecting Data Values from the Type Control will display the chosen physical property's data values. The data values are displayed in the units shown in the units rows near the top of the table. A green triangle in the upper right corner of the table control indicates that additional data are available. (See documentation on the Temperature-Pressure-Value-Reference All Data Dialog for details on managing data of different status.)

Clicking the left mouse button on the data values table control activates the Temperature-Pressure-Value-Reference Edit Dialog enabling you to enter a temperature, pressure, value, accuracies, units, reference, and comments. (See here for documentation.)

Clicking the right mouse button within the data table control displays the field's data commands menu.

The menu's commands enable you to copy, cut and paste values to and from the data table control. See Common Menu Commands for documentation on the commands commonly found on command menus. Some of this field's more specific commands are:

• Edit All Data: uses the All Data dialog to enable editing data having status values of passive, rejected or unknown. See All Data Dialog for for documentation.)
• Edit Data: enables you to view and mofidy the current physical property's datum. The property value, accuracy, units of measure, reference and comments can be viewed and edited. See Data Edit Dialog for detailed documentation. (Clicking the left mouse button on the table control will also execute this command.)

  Each property field runs a set of verification tests to check the validity of an entered value. For example, the liquid density must be a number greater than 0.0 kg/m3. Cranium or Synapse will signal an error if the entered value fails a physical property verification test.

1. Open a "working" copy of the MKS Core Knowledge Base document or create a copy of the document. See here for details on how to create copies of documents.
2. Change to the Chemicals Chapter and navigate to difluoromethane. (See the Navigation Overview documentation for details on navigating chapters and pages.)
3. Scroll down to the Temperature and Pressure Dependent section and click the left mouse button in the property control. The application activates the Properties - f(T,P) dialog.
4. Select Speed of Sound, Vapor - f(T,P) from the list of properties and Data Values from the list of values types.
5. Press the OK button. The application will close the dialog and display any current Speed of Sound data.
6. Click the left mouse button anywhere in the large values area of the section's table control. The application activates the Property Data dialog.
7. Click the left mouse button on a row in the table control. Press the Edit button. The application activates the Property Data Entry dialog.
8. Enter values for the state variables (the temperature and pressure in this example). Press the OK button when finished. This datum is added to the Property Data dialog.

   Note that datum entry dialogs manage data in their original units. Data dialogs and fields display manage data in their current, converted units.

9. Press the Save button to store these values in the document and display them in the field's table control.

Further details on the use of the data and datum entry dialogs can be found here.

Selecting 'Estimates' from the Value Type Control (see above) will display the chosen physical property's estimated values. Estimated values are displayed in the units shown in the units rows near the top of the table.

Before temperature and pressure dependent estimates can be generated, you must enter one or more temperature + pressure values. Clicking the left mouse button on the estimated values table control activates the Temperature-Pressure-Estimates Detail Dialog enabling you to enter temperatures and pressures, view estimated values, and review estimation comments. (See here for documentation.)

Clicking the right mouse button on the estimated values table control displays the estimated values table control's commands menu.

The menu's commands enable you to copy, cut and clear values from the estimate control and manage the property's estimation techniques. (You can paste temperature values but you cannot paste estimated values into the control.) See Common Menu Commands for documentation on the commands commonly found on command menus. Some of this field's more specific commands are:

• Edit Variables & Detail Estimates: activates the Property Estimates dialog.

  The Estimates dialog enables you to view estimation details, enter state variables for new estimations, copy values, regress values and use Goal Seek to find state variables giving specified estimated values. See Estimates Dialog for documentation on these capabilities.

• Select Technique: enables you to specify the estimation mode and the estimation technique used to estimate the current physical property. Selecting this command activates the Estimation Technique Information dialog.

  The dialog lists two estimation modes: Automatic and Manual. By default all estimations are initially set to Automatic Mode. Once you choose Manual Mode, the list of estimation techniques is enabled allowing you to choose any application estimation technique. See the Manual Techniques Dialog documentation for more discussion about manually setting estimation techniques.
• Compute Estimates: activates the Property Estimation dialog which enables you to estimate the current physical property. The functionality of this command is similar to that of the Commands menu Compute Estimates command. The key difference is that the estimates control's menu command limits the estimation to only the current physical property. See Estimate Chemical Properties for documentation.

Note that although state variable values, e.g., temperatures and pressures, can be pasted into the estimates table control, estimated values cannot be pasted into the estimates table control. Estimated values must be generated using the Compute Estimates command describe previously.

The values entered into the section's Curve Points Table are displayed as curves in the section's graph. Curves can greatly help visual trends in values and help organize values at different state conditions or from different references. For this section, curves are often used to differentiate data and estimates at different pressures.

You display the Curve Points Table by selecting the "Curve Points" values type in the Properties dialog. (See above.)

Clicking the right mouse button on the curve points table control displays the commands menu.

The menu's commands enable you to copy, cut and paste values to and from the curve points table control. See Common Menu Commands for documentation on the commands commonly found on command menus.

The Edit Values menu command activate the Curves Edit dialog. See documentation on the Curves Edit Dialog for details.

Temperature and pressure dependent properties are often measured over a range of temperatures at a few fixed pressures.

1. Open a "working" copy of the MKS Core Knowledge Base document or create a copy of the document. See here for details on how to create copies of documents.
2. Change to the Chemicals Chapter and navigate to 1,1,1,2-tetrafluoroethane (R134a). (Another chemical with speed of sound data values will do but the numbers given below will need to be modified.) (See the Navigation Overview documentation for details on navigating chapters and pages.)
3. Scroll down to the Temperature and Pressure Dependent section and click the left mouse button in the property control. The application activates the Properties - f(T,P) dialog.
4. Select 'Speed of Sound, Vapor - f(T,P)' from the list of properties and Curve Points from the list of values types. Press the OK button. The application will close the dialog and display the Curve Points table.
5. Click the left mouse button anywhere in the large values area of the table control. The application activates the Curve Points entry dialog.
6. Click the left mouse button on a row in the table control. Press the Edit button. The application activates the Curve Point Entry dialog.
7. Enter values for the temperature, pressure, curve point value, curve name and comments. Press the OK button when finished. The datum is added to the Curve Points dialog. (Copy the values from the Curve Points dialog shown above.)
8. Press the Save button to store these values in the document.
9. Scroll downward to display view the section's graph. The graph initially shows temperature as the variable on the X axis. Click the right mouse button on the graph and select the Edit Graph Attributes from the command menu. The application displays the XY Graph Attributes Dialog.

   1	Y Attribute: Displays the attribute being displayed on the graph's Y axis.
   2	X Attribute: Displays the attribute being displayed on the graph's X axis.

10. Click the left mouse button on the X Attribute control and select Pressure. (See documentation on XY Graph Field Edit Dialog for details on editing graph attributes.)
11. Press the dialog's OK button. The graph will now display the speed of sound as a function of pressure. The graph shows the lines formed from the entered curve points. The speed of sound varies mostly linearly over the pressure range selected.

Values for temperature and pressure dependent properties are often fitted to equations for analysis and dissemination. The section's Equations Table enables you to store one or more equations for each physical property.

Each equation entry displays the equation's name, form and parameters. The dependent variable is not shown and the independent variable is denoted by the character "X". Note that for this section, X can represent either temperature or pressure.

The section's Equations Table displays the chosen physical property's equation and parameter values. You display the Equations Table by selecting the "Equations" values type in the Properties dialog. (See above.)

Clicking the right mouse button on the equations control displays the command menu.

The menu's commands enable you to copy, cut and paste values to and from the equations table control. See Common Menu Commands for documentation on the commands commonly found on command menus.

The Edit Equations menu command activate the Equations Edit dialog. See documentation on the Equations Edit Dialog for details.

It is typically better to enter large compilations of equations and/or equation parameters in an estimation technique. See documentation for the Techniques Chapter's Parameters Section for details.

Selecting new units from the list and press the OK button changes the current units in which the property is displayed. (Note that all data are stored in their original units - changing the displayed units does not change any stored data.) The dialog's Std Units button displays the default units used by Cranium and Synapse for the current physical property. All estimated values are generated by Cranium and Synapse in standard units. (See documentation on the Property Units Dialog for additional details on changing property units.)

The units set via the Set Property Units dialog, accessed either from the Options menu's Set Units command or clicking on the Units control in a physical property field, are assigned for all documents in the application. For example, if you have three knowledge base documents open and then change the units of the vapor pressure, all documents will update their vapor pressure displays using the newly selected units.

Also note that changing temperature or pressure units will change these values for all values throughout the applicatino. Thus, changing the temperature units in this section's table control will change the temperature units in the Temperature Dependent Section as well as the temperature dependent sections in the mixture chapter.

Units are also stored in the application. The next time Cranium or Synapse starts, the set of units used in your last session will be used again.

The section's graph control displays the selected physical property's data values, estimated values, and curve points on a single graph.

1	Data Values: data values are represented by squares, circles, upwards triangles, and downwards triangles. These symbols are always filled with either black, blue, or red color. Each datum reference is associated with a symbol having a different shape or color.
2	Estimated Values: estimated values are represented by diamonds. The diamond's internal color and border color are different for each different technique used to generate the estimated values.
3	Curve Points: curve points are represented by curves drawn through the given points. Curve points are typically assigned a curve name depending upon similar attributes, e.g., the two curves shown in the graph above are for temperature values equal 323.15 K (curve Temp:323) and 343.15 K (curve Temp:343). Each named curve is draw in a different color.
4	Units: values are graphed in their current units. These units are also appended to the default x and y axis labels.
5	Axis Limits: the default limits for the x and y axes are determined from the minimum and maximum of the data, estimates, and curve point values. These limits can be changed by using the Graph Attributes dialog (see below).

Clicking the left mouse button on a graph control activates the Values Details Dialog.

The Values Details dialog shows the description of each symbol or curve displayed on the graph. For data values, the description is the identifier of the associated reference. For estimated values, the description is the name of the technique used to generate the estimates. For curve points, the description is the name of the curve.

The Values Details dialog provides commands for reporting, transferring values to graph documents, and displaying references. See the documentation for the XY Graph Key Dialog for details.

Clicking the right mouse button on a graph control displays the control's commands menu.

• Edit Graph Attributes: activates the XY Graph Attributes dialog.

  The Graph Attributes dialog enables you change the attributes being displayed, transform values, set formats, and set axis limits. See documentation on the XY Graph Attributes Dialog for details.

• Show Reference Key: activates the Values Details dialog which shows the description of each symbol or curve displayed on the graph. See documentation for the XY Graph Key Dialog for details.
• Examine Graph: activates the Graph Examination Dialog which enables you to select and identify each point displayed in the graph, zoom into specific areas of the graph, and fit curves to selected values.
  See documentation on the XY Graph Examination Dialog for details.
• Edit Static Curves: activates the Static Curve Points edit dialog which enables you to add curve points that will appear on every Temperature and Pressure Dependent Property Section's graph in the current document. Static graphs are very powerful tools for comparing the physical property values of different chemicals and mixtures. See documetation on Using Static Graphs for details.
• Copy Graph: copies an image of the graph onto the clipboard for pasting into other applications.

Topic	Description
Estimating Chemical Properties	a short video demonstrating how to estimate physical properties using either Synapse or Cranium.
Getting Started using Cranium	provides a quick tour of Cranium's capabilities including a discussion of structure editing.
Chemicals Chapter	the chemicals chapter contains numerous sections for entering and displaying data and estimates including the chemical structure section.