Tecfluid SC250H - Manual (Page 4)

4
4 OPERATION
Once the meter is installed, the regulator valve should be opened slowly. The fluid flow
will move the float which, through magnetic coupling, moves the indicator needle.
Any variations of working conditions with respect to calibration can induce reading errors.
The calibration working conditions are indicated on the instrument’s data plate.
4.1 Gas flow measurement (Figure 1)
The working pressure is of maximum importance for correct gas measurement as it
directly affects the scale readings.
For example, if a meter is calibrated for 2 bar gauge and the working pressure is 1 bar
gauge there will be an error of about 22%.
If the fluid to be measured is a liquid, it is advisable to install a regulating valve BEFORE
the flow meter (Figure 2).
In GAS measurements it is recommended to install the valve AFTER the flow meter, in
this way the working pressure can be kept the same as the calibration pressure. (Figure
1).
Valves should always be opened slowly to avoid water hammers that could damage the
inner components of the instrument (float, stops).
3.1 Filters
The installation of a filter before the instrument is important, this will avoid possible
obstructions and breakdowns in the measuring system.
The mesh of the filter should be 1,5-2 mm.
In the case of having abundant magnetic particles in suspension, it is necessary to mount
a magnetic filter on the inlet of the instrument in order to avoid the accumulation of
particles around the float due to its magnetic field, being possible that it finally gets
blocked.