MTDATA – Phase Diagram Software from the National Physical Laboratory

 

 

 

Home 

News 

Products 


Training and Support 

FAQs 

Links 

Agents 

Other Services 

 

Services 

 

 

STEP

Function:

allows the user to specify stepped values of the temperature, pressure/volume, amounts of individual components and/or substances and molalities prior to a calculation. The following variables may be stepped. In each case, except for the "group name", the start, final and step values are required. In the case of the "group name" it is necessary to specify two previously defined names and the number of calculations to be carried out. For details of the meaning of (*) and the values to be entered, please refer to the description of the SET command. Only one variable may be stepped at a time; any previous stepped variable is given the default SET value. Note: the totals N and W cannot be stepped.

Parameters:

volume_ideal_gas

system_volume

n(*)

temperature

w(*)

x(*)

pressure(*)

molality(*)

lgt_molality(*)

lgt_pressure(*)

<"group name">

Defaults:

No stepping.

Examples:

step temperature 500 2000 25 !

step volume 0.002 0.050 0.002 !

step lgt_molality(h/+<aq>) -14 0 0.2 !

set n=1 ! step n(2)=0.01 0.99 0.02 !

General comments:

The variables that can be stepped are the same as those that can be SET, except for the omission of the totals W and N. Only one variable can be stepped at a time; the latest overwrites the previous stepped variable. In order to avoid the previously stepped variable being assigned an indeterminate value, it is important to SET it to the value required for the next calculation.

 

Updated 9 June 2011