UltraLo-1800 Alpha Particle Counter
XIA LLC
Page 45
5.
Start Run Dialog
The Start Run Dialog launches whenever a measurement is
started, which is done by clicking the Run Control Button. As
shown in Figure VI-11 it contains five distinct parts:
a)
Acquisition Time
The Acquisition Time box is where you will set your desired
measurement length. The box is designed to be smart and
recognizes many different syntaxes for run length. For
example, to run for 1 day, 2 hours, 3 minutes, and 4 seconds,
you can enter “1d 2h 3m 4s”, or “1.2:3:4”, or even “1 day, 2
hours, 3 minutes, 4 seconds”. Not all of these parameters need
to be entered every time, “1d” is a valid time, as is “1d 4s”. The
box will indicate an invalid time by turning its border red, if the
border remains normal the time entered is valid. Finally, the
box saves the 5 most recently used durations, and will auto-
complete them as the user types if one is matched. They can
be selected via the pull-down arrow. Note that this time does
not include the purge time (which is normally 45 minutes, see
next section).
a)
Purge Check-Box and Duration
Most of the time you will be switching samples between
each measurement, which requires a purge. Occasionally you
may want to start a run without purging in order to remeasure
the current sample. In this case simply uncheck the purge box
and the run will begin immediately after hitting the Start
button. CounterMeasure will remember whether the box was
checked on the previous run and keep that setting for the
subsequent measurement.
Underneath the Acquisition Time box is a small clock
symbol, clicking it will reveal the Purge Duration box (see Figure VI-11, top and middle). This box sets the
purge duration, which is by default set to 45 minutes. This value can be changed in the same manner as
the Acquisition Time box. The only situation where we recommend changing the value is to conduct a
longer purge after the counter was opened (or otherwise without purge gas) for an extended period of
time. In this case the duration should be increased proportionally to how long the counter was open
(being open for 5 minutes may only require a 70-minute purge, being without gas for a week may
require a 2-hour purge). This value is not remembered run-to-run, it will always revert to 45 minutes
after being changed. Finally, we strongly recommend never setting this value below 45 minutes, as
that’s the minimum required time for the chamber to completely purge.
Figure VI-11: Start Run Dialog, default (top), with
Purge Duration box shown (middle), and with
custom parameter “Notes” (bottom).
