Curve: In a pressure decay leak test, the graph of the
drop in pressure (Y axis) over time (x axis) is called the
decay curve. TME uses the decay curve in its "Test Plot"
graphic display and in its "Memory Reference Curve"
technology, in which the decay curve for an acceptable test
part is determined and reject decisions are made by the test
instrument by comparing the test decay curve to the acceptable
"memory reference curve" for the test part.
Resolution is the least significant
digit that an instrument is capable of measuring; for example,
the TME Solution Leak Tester has a resolution of 0.0001 psi.
is the smallest volume leak rate your test system (including
the air lines, fixtures, etc.) can detect.
Pressure units of measure include: psig
(pounds per square inch gauge), Pascals, kg/cm2 and many
Flow rate units of measure include: liters/min,
sccm (standard cubic centimeter per minute), sccs (standard
cubic centimeters per second) - where standard refers to
Any sensor that converts a physical parameter (for example,
pressure) into an electronic signal that can be utilized
by an instrument.
Leak Rate: change in volume per unit of time (measured in
Flow Rate units of measure, see above)
Pressure Leak Rate:
change in pressure per unit of time (measured in Pressure
units of measure, see above)
Test Parameters: the descriptive factors defining a leak,
flow or package test.
These may include:
settle, and test times for pressure or vacuum decay tests;
Flow rate into the test item (very important
in burst testing);
Maximum acceptable volume leak rate.
vs. Concurrent Testing:
Concurrent testing enables
leak tests to be performed simultaneously on more than one
and up to four test items in a Solution tester, with one
test item connected to each port on the instrument. The tests
must have identical test parameters (test time, pressure,
decision point etc.), and the test results are discrete and
identifiable to a specific test part. An instrument of this
type has individual transducers for each test port.
testing involves performing a series of like tests on a test
item through a single port. An example is a leak test followed
by a flow occlusion test on a test item and/ or a series
of leak and flow tests on multiple ports. An instrument of
this type may have one port or multiple ports that are tested
one at a time.
An occlusion is a partial blockage of a flow path. An example
is a crimp in a catheter. Occlusion testing can be done in
several ways, including:
1. mass flow rate
3. pressure drop measurement.
pressure: the pressure forcing air through a leak path.
Testing: Based on international standards and FDA guidelines,
thorough package testing should consist of both seal strength
testing and leak integrity testing.
Strength Testing: a destructive test that provides a
measurement of the strength of a package seal of a porous
or non-porous package. Seal strength testing can also identify
the area of weakest seal. Seal strength testing can be done
using inflation tests or tensile tests, but TME recommends
using one or more of the following inflation seal strength
1. Burst testing (recording the peak or ultimate
strength of a package seal);
2. Creep Testing (measuring
resistance to seal peel) - result is pass/fail only;
Creep-to-Failure (measuring resistance to seal peel) - result
is variable statistic (time).
Testing: a measure of the quality of the package or product
in general, including the seal areas and the package or product
materials themselves. Leak Integrity Testing generally refers
to product or package leakage measured by a leak test.
Fixtures are used to enable the test instruments to perform
specified leak, flow or package tests on a variety of products
or packages. Examples of fixtures commonly used by TME include:
Open Package Test Fixtures, Closed Package Test Fixtures,
Restraining Plate Fixtures, Package Probe Assembly, Radial
Sealing Fixtures. Fixtures are often custom designed to accommodate
a customer's very specific testing need.
Package Entry System: a method to obtain a leak tight
measuring path between the package interior volume and the
instrument's pressure transducer. TME uses the patented Package-Port
System, which consists of the following disposable items:
Package-Port - a reusable plastic entry port which accommodates
the pressurizing sensor probe, and
2. Adhesive Disks that
adhere the Package-Port to the surface of the test item which
are supplied in rolls of 1000.
(Chamber) Testing: a method to non-destructively test
a sealed, non-porous package or product for leaks. It is
necessary that the test item contain some air or other gas
inside - this is called the "head space". The package
or product is enclosed in a surrogate chamber that provides
an interstitial air space around the test item. This air
space is then pressurized and stabilized, and decay of the
pressure in this air space (indicating air leaking into the
head space of the package or product) is measured. A chamber
test can also be done using vacuum.
Chamber: the test chamber used in non-destructive chamber
leak testing is called a "surrogate chamber" because
the actual pressure or vacuum decay leak test is done on
the air contents of the chamber surrounding the test item
rather than on the test item itself.
A designation in the USA which indicates that an item (such
as case, components, or an assembly) can withstand damage
from harsh industrial environments, including water or dust.
The NEMA-4 designation corresponds to the IP-65 designation.
These terms describe a process that is helpful when evaluating
a new product or package manufacturing process:
refers to the test and inspection results for each individual
component and/or step involved in the manufacture and packaging
of a medical device.
2. Qualification is a combination
of verifications to determine how well equipment, materials,
and a process can work together.
3. Validation is the
combination of various qualifications and other objective
evidence that the processes consistently produce product
meeting predetermined specifications.
Installation Qualification, Operation Qualification, Performance
Qualification. These protocols are part of the validation
process addressed above.