Bruce
Vishay doesn't publish a beta value that I can find, they do publish a table of resistance vs temperature values that can be used to calculate the appropriate beta.
The beta for the thermistor calculated from 0C-100C is 3947
I have attached the spreadsheet that I used to calculate the value.
you can get the data sheet from Mouser or vishay.
If you are using the default value of 3480 it is unlikely that the beta value is the problem.
You did not ask but the rz value is 32660.
The most common reason for the temperature being off is having the wrong value entered for the capacitor.
best,
Dan
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Beta_ Calculator2.xls
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