172-65639M-01 (EF200) 13 Apr 2018
7
2.2 Steam Dryness Fraction Calculator
EF200F ordered with the “Steam Dryness Fraction
Calculator” option is not only capable of flow rate
measurement but can also calculate the dryness
fraction of steam.
Measurable range: 80 to 100% (See the figure on
the right for measurement accuracy)
NOTE: Steam dryness fraction is an indication of steam quality. It shows the
ratio of steam by mass in wet saturated steam.
Steam Dryness Fraction
(
%
)
=
Steam mass flow rate
�
Steam mass flow rate
+ Water mass flow rate
�
×
100
Caution!
This option cannot be used with EF200W or EF200R.
There are a number of points to consider for the Steam Dryness Fraction
Calculator. Ensure these are met when installing.
Applicable Models
•
EF200F (Flanged) DN 25 – 100
Applicable Operating Conditions
•
Pressure: 0.1 to 1.0 MPaG (1.0 to 10 barg)
•
Temperature: 120 to 185
°
C (Saturation temperature for the pressures above)
•
Use at a stable pressure and flow rate.
Steam pressure is input in fixed values, therefore correct measurement is
not possible with large pressure fluctuations.
•
Make sure the flow rate falls within the measurable range of flow rates at
pressures between 0.1 and 1.0 MPaG (1.0 to 10 barg)
The measurable ranges for flow rate and for steam dryness fraction are
different. Refer to the table below to identify if the Steam Dryness Fraction
Calculator option is applicable.
Caution regarding installation of devices equipped with the Steam
Dryness Fraction Calculator
(see 3.3)
•
Ensure the required length of straight piping, without using a flow conditioner
•
Install on horizontal piping with the display facing downward
Caution!
•
When equipped with the Steam Dryness Fraction Calculator function, the
EF200F can be used with steam and water, but cannot be used with air.
•
When using the Steam Dryness Fraction Calculator function, the measurement
accuracy for steam mass flow rate will decrease from
±
2
°
C to
±
4
°
C.
Measurable flow rates for saturated steam when used with the optional
Steam Dryness Fraction Calculator EF200F
(Unit: kg/h)
Size (mm)/DN
25
40
50
80
100
Temp.
(
°
C)
Pressure
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
MPaG barg
0.1
1
11
66
27
233
44
349
99
872
171
906
120.4
0.2
2
14
96
35
340
57
510
128
1,272
221
1,323 133.7
0.3
3
19
126
45
445
75
668
167
1,666
289
1,731 143.7
0.4
4
23
156
55
548
92
823
206
2,054
356
2,135 151.9
0.5
5
27
185
66
651
109
978
244
2,438
423
2,534 158.9
0.6
6
31
214
76
753
126
1,131
282
2,820
489
2,931 165.0
0.7
7
35
243
86
855
143
1,283
320
3,200
555
3,326 170.5
0.8
8
39
272
96
956
160
1,435
358
3,579
620
3,720 175.4
0.9
9
43
301
106
1,057
177
1,586
396
3,955
686
4,111 179.9
1.0
10
48
329
116
1,158
194
1,737
434
4,333
751
4,503 184.1
Consult TLV for measurable flow rate data in imperial units.
Note!
Caution!
Caution!
80%
90
100
+5
0
-
2
-
5
Measurable Range
Steam
Dryness
Measurement Accuracy of
Steam Dryness
A
ccu
ra
cy
%
