slightly increased liquid viscosity

Hi, dear all

I have one question about eos1.

To construct a sensitivity matrix 'co' in subroutine 'multi' ,

we obtain secondary parameters using slightly increased primary variables, 

and then the parameters are stored in a matrix 'par' .

By the way, my question is about liquid water viscosity.

To calculate liquid viscosity we require three variables ;

pressure, temperature, and saturated vapor pressure.

However, when the temperature slightly increase, why the saturated vapor pressure does not change ?

Best Regards,

Yamamoto