Vaisala Spectrum 4.0 - Manual (Page 32)

Getting Started
26
To set the Stop Mode:
1. Under Stop Mode, select one of the following options:
The Log Time drop-down lists enable you to set an elapsed time for the data
logger to collect samples. For example, you can set the data logger to collect
samples for 24 hours, 48 hours, 7 days, and so on.
The Stop Time drop-down lists enable you to set absolute date and time values
for when the logger is to stop taking samples.
Note: The Log Time and Stop Time options are interrelated. Setting the Log
Time to a specified period automatically adjusts the Stop Time values.
Adjusting the Stop Time Date and Time values, in turn, automatically
adjusts the Log Time values.
Setting the Sample Interval
You can change the sample intervals on the logger to suit the requirements of
the application. You can set up more frequent sampling intervals to capture rap-
idly changing data, or spread out the readings to maximize memory and cover
extended monitoring periods.
Wrap when full This is the default method of collecting samples on
the data logger. When you choose this setting, sam-
ples are recorded in a first in, first out manner. When
the memory is full, the logger continues to take sam-
ples by discarding the oldest one, and replacing it
with the newest one.
The Wrap when full setting ensures that you always
have the latest data when you transfer from the data
logger. The length of time that the memory fills and
wraps around is a function of the Sample Interval
(see Setting the Sample Interval on page 26) you have
set on the logger. Veriteq Spectrum automatically
calculates this time and displays it in the Log Time
section of the Logger Sample Timing window.
Note: If the memory wraps around too quickly, you
can choose a longer sample interval.
Stop when full When you choose this method, the logger stops tak-
ing readings once the memory is full. This option al-
lows the maximum amount of samples to be taken
without overwriting data. It is particularly important
in any application where there is an excessive time
delay between the gathering of the data and the trans-
ferring of that data to the PC.
Stop at specified
time This method enables you to set a precise time for a
logger to stop recording data. When you choose this
setting, both the Log Time and Stop Time sections
of the Logger Sample Timing window are available.