Ulvac HELIOT 301, Инструкция по эксплуатации

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4-6-7 How to use the internal calibration leak
This function allows the internal calibration leak to be opened and closed at will during test.
If quick start is used for startup, for example, all the previous data will be used as they are.
The problem here is whether the condition of this startup is exactly the same as the previous
condition. Factors that determine the startup minimum sensitivity include the background
and ion source contamination.
To solve this problem, the calibration leak is opened/closed. The calibration leak is opened
in the test condition after start-up by quick start to verify leak rate. If the leak rate is
displayed as indicated on the rating plate (direct reading), the minimum sensitivity of
HELIOT is equivalent to that of the data obtained previously.
Auto flow fine
1.8E-10 Pa·m
3
/s
↓
Press
1) Test is under way by auto flow. Press the mode switch
when the leak rate has lowered and is stabilized.
Auto flow fine
*2.2E-08 Pa·m
3
/s
2) The * mark is displayed at the head of leak rate and the
calibration leak opens.
↓
Auto flow fine
1.8E-10 Pa·m
3
/s
3) Press for a second time. The calibration leak closes,
returning to the normal test condition.
* When the calibration leak is opened/closed, only the direct reading is verified.
Since test by quick start involves the possibility of error in the display value, use normal start to
start and execute test if an accurate leak rate is to be measured.
* The calibration leak is calibrated at 24°C.
If the temperature in HELIOT is not 24°C, the output leak rate will change. The calibration leak
tube surface temperature is measured by a temperature sensor for correction, but it may not be the
same as that on the rating plate.