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Reference:
List of Terms and Where to find additional information
Abort a test, how to
Press the start button during the test. ABORT pops up in the status box telling you the
process has stopped. An aborted test does not register on the tested or reject counters.
Atmosphere (1)
in this guide,
atmosphere
means room air pressure. Atmospheric pressure is nearly synonymous
with barometric pressure
—an external force pushing on all sides of every object on earth’s surface. During a flow
test, product being tested must flow into atmosphere, which causes a resistance to flow called back-pressure.
Room atmosphere can change due to fluctuations in air conditioning or changing weather conditions.
(2)
The word
atmosphere
can refer to a unit of measure equal to pressure at average sea level. By convention, one atmosphere
equals 1 bar. To say a test was taken at one atmosphere means the test was made at (or converted to) average
sea level.
Barometric Pressure
Also called atmospheric pressure. The force caused by the mass of air pressing down on
the earth. Barometric pressure changes with elevation and weather conditions. Isaac’s regulator comp
ensates for
changes in barometric pressure to provide a constant relative output.
Bulkhead Fitting
A connection passing through a panel or enclosure. One bulkhead on the back of Isaac is used
for connecting the air supply to the tester. Bulkheads on the front are used for test and coupling ports. Standard
bulkheads on the front have a 1/8
”
NPT (similar to R1/8 BSPT British Standard Pipe Taper) female thread. Isaac
offers a variety of bulkhead options.
Burst Test
One of Isaac’s three possible operating mo
des in addition to pressure decay and flow. A burst test
slowly fills a product through a flow control valve set by users. After the burst, pressure rapidly drops to near zero.
Isaac captures the pressure immediately before the product ruptures or in some way opens to atmosphere. Burst
mode is useful for testing pop-off valves, package seals, or devices that open to atmosphere after reaching a
predetermined pressure.
Calibration
Comparison of a device (such as Isaac) to a standard that is in turn calibrated to an even more
accurate standard.
Calibration Data
Values entered into Isaac through software calibration. Calibration data is stored as a look-up
table in Isaac’s non
-volatile RAM and is used to linearize pressure and flow transducer output at known pressures
and flow rates.
Calibration Screen
Calibration allows comparison of Isaac to pressure and flow standards. The calibration screen
shows Isaac’s actual reading and the pre
-programmed target value the technician compares to the pressure of flow
standard. Only qualified technicians who have proper training and resources should calibrate Isaac.
Counters
Isaac records the total number of tests performed (both pass and fail) and the number of rejects (fail
only). Running totals are displayed in the
Test Cycles
and
Failures
fields on the Main screen.
