Page 97
Fill Timer
At the start of fill time, a valve opens to pressurize the product. Fill
duration depends on the size and construction of the part to be tested.
Optimum fill time pressurizes the part fast enough for a good throughput,
yet not so fast that the product is still expanding during test phase. Large
products require a larger fill time than smaller products. At the end of fill
time, Sprint LC closes the supply air valve and pressure is trapped inside
both the part and test circuit of Sprint LC.
Stabilization Timer
This time is provided to let pressure settle before going into the test phase.
Best established through trial and error, stabilization time varies
depending on product characteristics. Start with stabilize and test times
that are equal to each other. The Stabilize time is used to get the maximum
separation and repeatability in test results between a known good part and
a borderline failure. If the same part is tested repeatedly and the leak result
is inconsistent, try increasing the stabilization time. The smaller the leak,
the longer the time.
Test Timer
In a pressure decay test, test time is the period when Sprint LC takes
measurements to determine the amount of pressure drop from a stabilized
pressure. The instant the test enters test phase, Sprint LC takes the first
pressure reading and stores this value P-1. At the end of test phase, Sprint
LC takes a final reading and holds this value as P-2. The difference
between P-1 and P-2 is the total test pressure loss over the test time. Test
time must be long enough to distinguish between good and bad parts. The
smaller the leak, the longer the time.
Dump Setting
Set dump to auto, off, or to a specific time. When active, dump opens a
valve at the end of test time to vent the product and the test circuit of
Sprint LC. If the operator or automated equipment removes the products
and vents the pressure, then dump is generally unnecessary (unless test
pressures are more than 50 psig) and this parameter should be set to OFF.
Dump is valuable when multiple tests are linked and pressure venting is
needed before starting the next step in the series. When set to auto Sprint
LC activates the dump valve and monitors the pressure until the pressure
drops below 0.5 psig, then closes the valve to be ready for the next test.
To Next Page
Loading...
