Chatillon DFE I, Руководство пользователя

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DF II Series User Manual
USING bREAK DETECTION (DFS II ONlY)
Break Detection is used when you want to capture
the break load of a sample. This function is use-
ful especially with samples that characteristically
yield before they actually break. The Break Detect
function provides you with the Peak Load and the
Break Load.
The DFS II Series gauge will report the following
as part of a Break Detect test:
n Break Load
n Break Point (Break Threshold)
n
% Drop (used to calculate the Break Load
from Maximum Load)
The Break Load is calculated as:
Break Load = (Peak Load)(% Drop)
The % Drop is a user-defined point that the gauge
will use to determine the break load. The % Drop
value is the percentage of the maximum load that
the DFS measures that you define as the Break
Load.
In some cases, the Peak Load is the Break Load.
However, with samples that yield before breaking,
the Break Load is often not the same as the Peak
Load.
Example: If the maximum load was measured to
be 100 lbf and the % Drop was setup as 80%, the
gauge will define the Break Load as 80 lbf.
If the maximum load was measured to be 50 N and
the % Drop was setup as 50%, the gauge will de-
fine the Break Load as 25 N (50 N x 0.5 = 25N).
The DFS II Series force gauge allows you to per-
form two different types of Break tests:
n Sharp Break Test (95% Drop Fixed)
n
Percentage Drop (% Break) Test
A Sharp Break is defined as a 95% drop in mea-
sured load from the recorded maximum load. The
95% Drop is a preset and cannot be changed by
the user. When the load drops to a value equal to
95% of the maximum load, the gauge will identify
this point as the Break Load.
A Percentage Drop (% Break) is a user-defined
drop in measured load after the maximum load.
You may select the desired % Drop to be used to
calculate the Break Load.
Noisy samples, such as adhesives or peel tests
should be specified with a high % Drop and with
the Peak Filter set at 10Hz. Setting the % Drop
too low may cause the gauge to sense a break be-
fore a break actually occurs. Conversely, samples
that are rigid may use a high % Drop value. How-
ever, rigid samples typically break at a value equal
to the Peak Load.