Application information, liquid, Viscosity effect (sus/cst), Density effect (specific gravity) – Badger Meter MR Transmitter User Manual
Page 19
APPLICATION INFORMATION, LIQUID
Viscosity Effect (SUS/cSt)
The design uses a precision machined, sharp- edged orifice and biasing calibration spring that assures operating stability and
accuracy over the wide viscosity range common to many fluids . Generally, high flow models of each meter size provide good
accuracy over a viscosity range of 40…500 SUS (4 .2…109 cSt) .
Density Effect (specific gravity)
Any fluid density change from stated standards has a proportional effect on meter accuracy . Corrections for more or less
dense fluids can be made to standard scales using the following correction factor:
1 0
.
Specific Gravity
For water/water-based meters
0 876
.
Specific Gravity
For petroleum-based meters
Application Information Pneumatic
OTEE:
N
Pressure and temperature readings must be taken at the flow meter inlet to ensure accurate correction factors .
The pneumatic flow meter is calibrated for air in standard cubic feet per minute (scfm) at 1 .0 s .g . (70° F @ 100 psi), and liter per
second (lps) at 1 .0 s .g . (21° C @ 6 .9 bar) .
Pressure
Gauge
Air Bleed Off
To Equipment
Pressure
Source
Adjustable
Valve
Flow
Meter
Temp
Figure 10: System schematic
DETERMINE FLOW RATES USING DIFFERENT PRESSURES & TEMPERATURES
scfm actual
scfm indicated
f x f x f
(
)
(
)
=
1
3
2
Where
f
1
= Conversion Factor for Inlet Pressure
f
2
= Conversion Factor for Inlet Pressure
f
3
= Conversion Factor for Inlet Pressure
Table 1–Temperature Correction Factor (f
1
) Operating Pressure
psig
25
50
75
100
125
150
175
200
225
250
BAR
1 .7
3 .5
5 .2
6 .9
8 .6
10 .4
12 .1
13 .8
15 .5
17 .2
kPa
172
345
517
689
862
1034
1207
1379
1551
1724
f
1
1 .700
1 .331
1 .131
1 .00
0 .902
0 .835
0 .778
0 .731
0 .692
0 .658
f
kPa
1
790 857
101 357
=
+
.
.
f
BAR
1
7 914
1 014
=
+
.
.
f
psig
1
114 7
14 7
=
+
.
.
Table 2–Temperature Correction Factor (f
2
)
°F
10
30
50
70
90
110
130
150
170
190
°C
–12 .2
–1 .1
9 .9
21 .0
32 .1
43
54
65
76
88
f
2
0 .942
0 .962
0 .981
1 .00
1 .018
1 .037
1 .055
1 .072
1 .090
1 .107
User Manual
Page 19
November 2013