Integritest Exacta Filter Integrity Test Instrument
Operating and Maintenance Manual Troubleshooting 207
Note: A red stripe will appear at the edge of the paper as it nears the end of the roll.
This indicates that you will need to change the paper soon.
System Lock-Up
• The instrument has failed calibration. Tests cannot be conducted until a successful
external fingerprint calibration is conducted.
• This may result from a software conflict causing the cursor not to respond. Press the
Ctrl-Alt-Delete keys simultaneously. Close the program that is not responding. Shut down
and restart the Integritest Exacta unit. ( See the section titled Starting/Stopping the
Instrument on page 49 for more details).
Exacta Gross Leak Criteria
The Exacta software is programmed to detect filter and or system gas leaks using the following
criteria:
• During any pressure decay measurement, the total pressure loss cannot exceed half the
test pressure.
• An equivalent diffusion flowrate must be less than twice the diffusion specification of the
filter. Any gas flowrate in excess of this value will be flagged as a gross leak.
• The first of these criteria is performed during every pressure decay measurement. This
includes the system sizing routine and during each of the pressure decays employed
during a diffusion or bubble point test.
The second criterion is performed twice during a filter test, prior to system sizing and after the
diffusion flowrate is determined. In a bubblepoint test, the second criterion is checked only
once which is after the initial diffusion flowrate is determined. No Gross leak check is
performed during the subsequent pressure steps. (Because the Exacta employs the tangent
method to determine the bubble point value, the diffusion curve for the filter must first be
established. This is accomplished by measuring the diffusion flowrates at different pressures
this includes the diffusion test pressure, 1psi below the bubblepoint specification, the bubble
point specification and 1psi above the bubblepoint specification.) For a bubblepoint test it is
at the diffusion test pressure that the second criterion is applied.
Gross Leak detection during the diffusion flowrate step
At the completion of the diffusion flowrate determination, the measured flowrate is compared
to the gross leak criteria equal to twice the filter flowrate specification. For a filter that has a
diffusion specification of 13.3 mL/min. this value would be 26.6 mL/min. Therefore, a
pressure drop that results in a flowrate value greater than 26.6 mL/min. would prompt this
message. For small area filters where a diffusion value is not specified, the value defaults to 3
mL/min. For small area filters the message would appear if the measured flowrate exceeds 6
mL/min. This determination is performed only once during the flowrate step.
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