Carbolite ABA 7/35B - Manual (Page 25)

25 MF60 – 1.04
7.5 Power Failure During Test
The door remains locked after a power failure. The key switch can be used to
override the lock, but this feature is not recommended because of danger to
the operator. Note that when power returns the display shows a message to
indicate the power was interrupted during a test, see screen view 7.5.1. The
test will re-start automatically, once the control software has started. The test
results should be discarded.
If the sample temperature within the chamber is under 120°C, or if there is no sample present in
the chamber, then it is permissible to immediately cancel the test using the procedure given in
section 7.7.
7.5.1 Screen-view: Power Interrupt During Test Warning
7.6 End of Test Trigger
The end of the test is determined by the three recipe parameters in Screen-view: 7.6.1. The
system can be set to use either Min % Weight Change or Constant Mass Limit; Screen-view:
7.6.1. shows the example where Constant Mass Limit has been selected. For a test to end, the
weight variation must be less than or equal to the set limit during the period defined by Constant
Weight Time. Note; the monitoring for the end of test conditions being met will not start until the
Initial Delay Time, defined in the recipe, has expired. This setting has a range from 0 to 60
minutes.
In ASTM D6307-10, the end of test is defined as when the change in weight of the sample does
not exceed 0.01% of the initial sample weight. In standard BS / EN 12697-39:2004 it is defined
as a constant mass limit, in grams rather than per cent, with different values for different
aggregate sizes.
When the end of test has been reached an audible alarm will sound every ten seconds and a
message dialog box will appear allowing the operator to cancel the beeper. The door will
automatically be unlocked. The final results will be printed out and saved to the Test Results log
file (refer to section 15 for more details).
7.6.1 Screen-view: Test End Parameters