Putting Into Operation; Purge Gas Flow; Baking Out Sample Tube And Glass Boat - Mettler Toledo DO307 Mode D'emploi

5.

Putting into operation

5.1

Purge gas flow

Gas flow with stop cock in open position.
This allows purging of the "cold zone" of the
sample tube (back purge).
5.2

Baking out sample tube and glass boat

– Connect the apparatus to the power supply with the power cable.
– Switch the instrument on: The temperature setting should be "Off" and the stop cock "open".
– Set the gas flow rate (200 – 250 mL/min) on the flow meter.
– Purge the "cold zone" of the sample tube for approx. 5 minutes. Meanwhile prepare the titrator so
that the drift can be measured.
– Baking out the oven and the glass boat:
• Close the stop cock to allow the purging of the "hot zone".
• Slide the boat to the end of the sample tube and set a temperature of 300 °C. The moisture in
the sample tube is transferred to the titration cell.
• Wait until the drift has dropped to below 50 µg/min (time required: approx. 15 minutes).
The system is now free from moisture and ready for measurement.
Notes
1. If the DO307 has been switched off for a relatively long time, you should always bake out the
sample tube and glass boat before the first measurement.
2. If the DO307 is in daily use, we advise you not to shut off the purge gas, but simply reduce the
flow rate to approx. 60 mL/min.
3. Open the stop cock before you stop the gas flow, switch off the apparatus or lower the temperature !
This prevents siphoning back of the titration solution into the hot drying oven.
DO307
METTLER TOLEDO
Gas flow with stop cock in closed position.
This allows purging of the "hot zone" of the
sample tube (cell purge) for moisture transfer.
Putting into operation
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