TSI Instruments SidePak AM520, Руководство пользователя

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Operation 27
Log Interval vs. Time Constant
•
The LOG INTERVAL is the time interval used between recorded
data points. It can be set using the SETTINGS menu and in
Program logging mode using TrakPro
™ software.
•
The AM520/AM520i always takes a measurement once every
second regardless of the Log Interval. Using a Log Interval
greater than one second results in stored data points that are
averages of the 1-second readings. For example, a 10-second
log interval will result in one stored data point every 10 seconds,
with each data point being the average of ten 1-second
readings. Using a longer logging interval conserves memory in
the instrument during long sample runs.
•
The TIME CONSTANT is an averaging period used to dampen
fluctuations in displayed readings so they are easier to read.
•
The AM520/AM520i always takes a measurement once every
second regardless of the Time Constant selected. Using a Time
Constant greater than one second results in displayed readings
that are averages of the 1-second readings. For example, a
10-second Time Constant will cause the display to show an
average of the most recent ten 1-second readings. This results
in a 10-second moving average, updated on the display
every second.
•
DO NOT
mistake “
Time Constants
” with “
Log Intervals
.”
Time Constants affect only the displayed information.
Log Intervals affect only the recorded data. Therefore, the
recorded logged data will generally not match the displayed
logged data at the same points in time.
•
When using general Alarms or STEL Alarms, the alarm is
triggered based on the displayed Time Constant reading, not the
value of the logged data over the Log Interval. Therefore, the
recorded logged data will generally
not match the alarm values
exactly. For instance, if a Time Constant of 30 seconds and a
Log Interval of one second are chosen, the displayed reading
will be smoothed out over 30 seconds. Since the Alarms trigger
from the displayed value and not the logged value, there could
be one or more data points saved in the logged Test with values
above the Alarm setting, but if the average over 30 seconds is
less than the Alarm setting, the Alarm will not trigger.