Uson SPRINT LC, Owner'S Manual

Page: 98 / 208

Page 98
Pressure Drop
Pressure drop is the amount of pressure change from the first pressure
measurement in test phase (P-1) to the last pressure measurement in test
phase (P-2). Decay rate is the pressure drop divided by time.
P-1 less P-2
Test Time
= Decay Rate
Although Sprint LC takes continuous pressure measurements from the
start of fill time, only two readings are used to calculate the pressure
drop—the first reading at the start of test phase and the last reading at the
end of test phase. Sprint LC uses the pressure drop to compare to the
maximum allowable loss (known as the reject level) to decide whether a
product is accepted as good or rejected as bad. The reject limit to enter
into the parameters menu is generally a low pressure value, such as 0.050
psig, because the reject pressure is the drop from the first pressure reading,
not the full pressure on the scale.
FIGURE 45
Fill Stabilize Test Dump
Zero
Couple
TIME
PRESSURE
First
Reading
Last
Reading
P1
P2
Pressure Drop
Pressure
Decay