Ppendix B - Magnetrol Thermatel TA2 Installation And Operating Manual

Appendix B
The flow measurement of the TA2 assumes that the end of the
probe is one inch past the centerline and the presence of a fully
developed flow profile. See Figure A.
Figure A
Turbulent Flow Profile
As gas flows in a pipe or duct, the flow profile will change with
obstructions and changes in flow direction. As the gas flows
around an elbow, the momentum causes the gas velocity on the
outside of the elbow to increase and the velocity on the inside to
decrease. See figure B.
FLOW
90-degree Elbow
FLOW
Two 90-degree Elbows in Plane
FLOW
Two 90-degree Elbows out of Plane
79
R = 3,000,000
D
R = 4,000
D
5
15 diameters
diameters
5
20 diameters
diameters
5
35 diameters
diameters
Figure C – Probe Installations
Figure B
Flow Profile Following
Single Elbow
Figure C, below, indicates the minimum recommended straight-
run distances required to obtain the desired fully developed flow
profile. If these straight-run distances are not available, the over-
all accuracy of the flow measurement will be affected; however,
the repeatability of the measurement will be maintained.
The user has the ability to enter correction factors to compensate
for non-ideal flow profile conditions.
Reduction
Expansion
Control Valve -
valves be installed downstream of the flow meter.
54-650 Thermatel ® Model TA2 Transmitter - F
FLOW
5
15 diameters
diameters
FLOW
15 diameters 5
diameters
FLOW
50 diameters 5
diameters
It is recommended that control
fieldbus
OUNDATION
™