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.
PCDManager Vapor Pressure Equations
Moderator: jasper
PCDManager Vapor Pressure Equations
- Attachments
-
- PCDmanager vapor pressure Eqn 201.pdf
- Table of Vapor Pressure Regression Equation Results
- (19.53 KiB) Downloaded 967 times
Re: PCDManager Vapor Pressure Equations
Harry will be back in his office 3 weeks from now. He will get back to you then.
Re: PCDManager Vapor Pressure Equations
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
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."
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
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.
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.