Ulvac HELIOT 301, Instruction Manual

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4-6-3 Gross leak flow
This flow executes roughing after starting test and automatically changes over the mode to the
test status when the test port pressure has come down to below 1000 Pa.
This flow is suited to an application where the leak rate of the test object is high or the
ultimate pressure does not reach 70 Pa. This permits test of the highest pressure and highest
leak rate by the vacuum method using HELIOT. However, its minimum sensitivity is low.
The following is an example of gross leak flow when the SEN. switch is set at L.
Test mode L
Standby
1) Start test from test mode standby. Securely connect the test
object to the test port.
↓
Press
2) Press the test switch once. Test starts.
Gross leak flow
Evacuating
↓
↓
3) Work is rough-pumped (evacuated). If the pressure does not
come down to below 1000 Pa within three minutes, error
processing is made for the roughing fault and stops and
invalidates the test.
Gross leak flow
Change Grs. flow
4) Roughing is completed and gross leak flow starts.
↓
Gross leak flow
*.*E-** Pa·m
3
/s
↓
Press
5) Test is being made by gross leak flow. Gross leak flow is
continued in this condition even if the test port pressure comes
down to below 70 Pa.
Test mode L
Standby
6) To end the test, press the vent switch . The test port is
vented to atmospheric pressure simultaneously with
completion of test, returning to test mode standby.
* If pressure does not come down to below 1000 Pa within three minutes after start of test, test will
be stopped and invalidated, displaying the error message "Evacuation fault".
* If pressure exceeds 1000 Pa after starting test, test will be stopped and invalidated, displaying the
error message "G. flow invalid".