Flowmeter
element |
Clean Liquid |
Dirty liquid |
Viscous liquid |
Gas |
Steam |
Rangeability |
Pressure Loss |
Typical
Accuracy,
percent |
Required
straight pipe length |
Initial cost |
Operation
Cost |
Remark |
Variable area |
2 |
1 |
1 |
2 |
2 |
10 to 1 |
Low |
±2 to ±10
of full scale |
None |
Low |
High: very vulnerable to process variability |
No power required. Allow direct process visualization |
Oval Gear |
2 |
0 |
2 |
0 |
0 |
20 to 1 |
High |
±0.5 of
rate |
None |
Low |
Medium |
Great for oil applications |
Mass
(Thermal) |
1 |
0 |
0 |
2 |
0 |
50 to 1 |
Low to medium |
±0.2 full
scale + ±0.7 rate |
Low |
Medium |
Low |
Not affected by density, pressure and temperature variations.
Wide flow ranges available |
Mass
(Coriolis) |
2 |
0 |
1 |
1 |
0 |
100 to 1 |
Medium |
±0.5 of
rate |
None |
High |
Low |
Very accurate. Direct mass measurement, multiparameter readout |