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PCDManager Vapor Pressure Equations

Posted: 20 July 2014, 01:00
by nrgeng
PCDmanager may have erroneously fit vapor pressure data to Eqn 201 not Eqn 200 (as stated in PCDmanager) since my calculated Coefficient E in Eqn 201 more closely matches that given in PCDmanager; and PCDmanager calculated an R2 of 0.999999, which more closely matches my calculated R2 of 0.999994. Please review the attached file.

PCDmanager seems to have fit the data to Eqn 201 while stating that it fit the data to Eqn 200. Please verify my hypothesis.

Re: PCDManager Vapor Pressure Equations

Posted: 20 July 2014, 15:06
by jasper
Harry will be back in his office 3 weeks from now. He will get back to you then.

Re: PCDManager Vapor Pressure Equations

Posted: 27 August 2014, 22:51
by hkooijman
please post PCD file of the component so I can reproduce the problem. without detailed info it is difficult to reproduce the problem

PCDManager Vapor Pressure Equations 2

Posted: 09 September 2014, 12:22
by nrgeng
I am using PCDmanager v6.96 (2100/6)

I attempted to repeat the steps from the original posting but encountered another problem this time.

Open PCDmanager
Click [Add New] type "Compound W"
<T Correlations >
select "vapor pressure"
<Table> #Points "12"
<Import> Text file "Compound W vapor pressure (K, Pa) 1.1"
<Plot>
Eq. No. "200"
<Fit>

Problem: Exception Report--"Invalid floating point operation"

Since there are nine data pairs, why do I need to set <Table> #Points to 12 to read in all nine pairs? If set to nine, then only six data pairs are read in.

I have emailed the file "Compound W vapor pressure (K, Pa) 1.1."

PCDManager Vapor Pressure Equations 3

Posted: 15 September 2014, 12:45
by nrgeng
I downloaded "new" version but same version number in [Help] [About] display. Why? I witnessed the download but the version had the same number as before. Do you (will you) change the version number so users know what is being run? Did I just reload the old version?

How to download new versions of PCDmanager? What procedure do you recommend?

Vapor Pressure Data Fitting
Problem: Exception Report--"Floating point overflow"
No Plot for Eqn 200

Seems to be the same problem as before. The number of <Table> points seems to read in the 9 data pairs (after the 2nd attempt).

Please continue to work on PCDmanager.