This procedure is meant to be carried out with no remarkable breaks, that is, breaks lasting over 2 hours.
To avoid contamination:
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Arrange the air flow meter as shown in the following figure.
- 1
- Stand
- 2
- Bosshead
- 3
- Connector tube 1
- 4
- Rubber bulb
- 5
- Flow meter tube
- 6
- Clamp
- 7
- Connector tube 2
- 8
- Dishwashing liquid
- 9
- Connector tube 3
- Fill the rubber bulb (4) and the flow meter tube with soap solution (8) almost up to the filling tube of the flow meter tube.
- Connect the air flow meter to the air exhaust tube of sensor cathode. Slip the connector tube 3 (9) over the short Teflon tube protruding from the top plug of the sensor cathode chamber.
- With the radiosonde air pump operating, squeeze the rubber bulb (4) slightly to cause several soap bubbles to rise up the flow meter tube. Repeat the process several times, until the bubbles reach the top of the tube without breaking.
- Form only 1 bubble, and use a stopwatch to determine the time (t) required for the bubble to rise from 0 to 100 ml up the flow meter tube (5). Repeat the measurement 3 times to obtain a mean value.
When the air flow is measured, make sure that the sensor is charged with the sensing solution. |