Endress+Hauser iTHERM TM411 - Medium - State of Aggregation

iTHERM TM412
Endress+Hauser 19
Example of the permitted flow velocity depending on the immersion length and process
medium
The highest flow velocity tolerated by the thermometer diminishes with increasing insert immersion
length exposed to the stream of the fluid. In addition it is dependent on the diameter of the
thermometer tip, on the kind of measuring medium, on the process temperature and on the process
pressure. The following figures exemplify the maximum permitted flow velocities in water and
superheated steam at a process pressure of 40 bar (580 PSI).
L (mm)
A
0
10
20
30
40
50
60
70
80
90
100 200 300 400 500
v (m/s)
B
0
4 8 12 16 20
L (in)
0
30
65
100
130
160
200
230
260
290
v (ft/s)
A0008967
 7 Permitted flow velocities, protection tube diameter 9.53 mm (3/8 in)
A Medium water at T = 50 °C (122 °F)
B Medium superheated steam at T = 400 °C (752 °F)
L Immersion length exposed to flow
v Flow velocity
Medium - state of
aggregation
Gaseous or liquid (also with high viscosity, e.g. yogurt).