Zaxis Isaac HD, Руководство пользователя

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Engineering Data:
Converting Pressure to Flow Rate
You can determine the leak rate in flow units (cubic centimeters per minute) based on the
pressures measured by Isaac. In a pressure decay test, Isaac holds the pressure drop on the
main screen. The pressure drop is the del
ta pressure (ΔP) in the formula.
Delta time (Δt) is the test timer value set in Isaac’s pressure decay program (provided the test
passes). With this timer being set in seconds, simply divide by 60 to get the delta time in
minutes.
Volume is the part volum e plus Isaac’s internal test circuit (approx. 1cc) plus the volume of
connections between Isaac’s test port and the product. The total volume (for our example)
must be in cubic centimeters.
Atmosphere is the absolute barometric pressure in mbar (approx. 1000 mbar at sea level). This
number changes with weather conditions.
➢
∆P = Decay in pressure, val ue shown at end of test.
➢
∆t = Test step time in minutes.
➢
Volume = Volume of product and leak tester and any fixture volume.
➢
ATM = Atmosphere pressure in mbar absolute.
Leak Rate
(cc/m)
=
∆ P
(mbar) ●
Volume
(cc)
∆ t (minutes) ● Atm
(mbar)