4. UsER INsTRUCTIONs AND sETUP
CThis leaflet is dedicated to the installer in charge of the setup
of the Ecro-RV, a product for laboratories, developed by the
Company COMELEC.
These few pages explain the different steps for an optimal set-
ting of this control device.
4.1 Installation and setting of the probe
Each fume hood is different from an aeraulic point of view.
The manufacturer must show the installer where the hot-wire
speed probe has to be placed so as to get the face air velocity.
If this emplacement is not respected, the speed measured by
the probe will be wrong.
Once the emplacement is determined, a 16.5 mm diameter has
to be made with a drill. The probe is mounted with its clamping
ring (included in the package).
4.2 Probe functioning principles
The depression (PL-PS) generated by air extraction creates a
way through the probe for the air.
The velocity of the air crossing the probe is identical to the one
at the entry of the fume hood.
The air crossing the probe coldens more or less a filament. This
begets a change of temperature.
This change of temperature permits to find the front air velocity.
4.3 Conditions de fonctionnement de la sonde
CAUTION, for an accurate measure of velocity, apart
from the position of the probe, it is important to make sure that:
- the air crossing the probe comes from the laboratory. For
instance, if the top of the fume hood is completely closed, the
measure will be wrong.
- The laboratory is not in high depression (because of a bad
compensation for example), otherwise the measure of velocity
will be wrong.
- No draught disturbs the probe – otherwise, you must protect it.
PL
PS
Sonde à
fil chaud
OUTSIDE
Hot-wire
probe
10
