Endress+Hauser Prosonic S FMU90 - The Formula for Flow Calculation

Appendix
197
13.2 The formula for flow calculation
If you have selected the "formula" linearization type, the flow calculation is performed according to:
Q = C (h
α
+ γh
β
)
where:
• Q: the flow in m
3
/h
• C: a scaling parameter
•h: the upstream level
• α,β: the flow exponents
• γ: a weighting constant
Appropriate values of α, β, γ and C for the different types of flumes and weirs can be taken from the
following tables.
Khafagi-Venturi flumes
Type Q
max
[m
3
/h] α β γ C
QV 302 40,09 1,500 2,500 0,0013140 0,0095299
QV 303 104,3 1,500 2,500 0,0004301 0,0238249
QV 304 231,5 1,500 2,500 0,0003225 0,0317665
QV 305 323,0 1,500 2,500 0,0002580 0,0397081
QV 306 414,0 1,500 2,500 0,0002150 0,0476497
QV 308 1024 1,500 2,500 0,0001613 0,0635329
QV 310 1982 1,500 2,500 0,0001290 0,0794162
QV 313 3308 1,500 2,500 0,0000992 0,1032410
QV 316 6181 1,500 2,500 0,0000806 0,1270659
ISO-Venturi flumes
Type Q
max
[m
3
/h] α β γ C
ISO 415 42,5 1,500 2,100 0,0009336 0,0146865
ISO 425 130,3 1,500 1,600 0,0959719 0,0214406
ISO 430 322,2 1,500 2,000 0,0032155 0,0379104
ISO 440 893,6 1,600 1,700 -0,2582633 0,0590888
ISO 450 1318,9 1,600 1,800 -0,0895791 0,0553654
ISO 480 1862,5 1,600 1,800 -0,0928186 0,0795737
British standard Venturi flumes (BS 3680)
Type Q
max
[m
3
/h] α β γ C
BST Venturi 4" 36,25 1,500 1,000 0,0000000 0,019732
BST Venturi 7" 90,44 1,500 1,000 0,0000000 0,034532
BST Venturi 12" 371,2 1,500 1,000 0,0000000 0,059201
BST Venturi 18" 925,7 1,500 1,000 0,0000000 0,088021
BST Venturi 30" 3603 1,500 1,000 0,0000000 0,148003