Calculation formula, Typical fl uid example – Yokogawa digitalYEWFLO (DY) User Manual
Page 125

<13. GENERAL SPECIFICATIONS>
13-15
IM 01F06A00-01EN
Calculation formula
■ How to calculate volume fl ow rate at operating
conditions.
• Q
f
= 3600×
×S or Q
f
= ×D
2
354
■ How to calculate the velocity of a Reynolds
number.
•
= 5× / D (Reynolds number of 5000)
•
= 20× / D (Reynolds number of 20000)
•
= 40× / D (Reynolds number of 40000)
where
• Re =
354×10
3
×Q
f
×D
········· (1)
•
=
f
×10
3
················ (2)
Q
f
: Volume fl ow rate at operating conditions
(m
3
/h)
D: Inner diameter of digitalYEWFLO (mm)
S: Sectional area of digitalYEWFLO (m
2
)
: Flow velocity (m/s)
Re: Reynolds number (non unit)
f
: Density at operating conditions (kg/m
3
)
: Viscosity at operating conditions (mPa·s (cP) )
:
Kinematic viscosity at operating conditions
(10
-6
m
2
/s (cSt) )
Typical fl uid example
Table 13.8
Range of Measurable Water Flow Rate
(At standard condition of 15°C,
ρ = 1000 kg/m
3
)
Model Code
Measurable Flow Rate
in m
3
/h
Range of Fixed
Accuracy Flow Rate
in m
3
/h
DY015
DY025/R1
DY040/R2
0.30 to 6
0.94 to 6
DY025
DY040/R1
DY050/R2
0.65 to 18
1.7 to 18
DY040
DY050/R1
DY080/R2
1.3 to 44
2.6 to 44
DY050
DY080/R1
DY100/R2
2.2 to 73
3.3 to 73
DY080
DY100/R1
DY150/R2
4.3 to 142
4.6 to 142
DY100
DY150/R1
DY200/R2
7.5 to 248
7.5 to 248
DY150
DY200/R1
—
17 to 544
18 to 544
DY200
—
—
34 to 973
34 to 973
DY250
—
—
60 to 1506
60 to 1506
DY300
—
—
86 to 2156
86 to 2156
DY400
—
—
177 to 3547
177 to 3547