from appendix B-2 for T=80F, 

Assuming a machined inlet cone ,     C = 0.995    (Table 10.1)

To check if the correct value of discharge coefficient (C) was used,  

This value of  Re is slightly below  the given value in Table 10.1. so the uncertainty in the value of C may be greater than





From Table 10.1, C=0.995

                        assuming T=20C,

To check if we chose the correct value of discharge ceofficient (C), 


The value Re is below the range of values in Table 10.1 so the value of C is more uncertain than 1%. This venturi should be calibrated for this application.