Ludlum Measurements 334A, Operation Manual

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Model 334A Operations Manual
Ludlum Measurements, Inc 6 January 2021
The Menu bar across the top of the screen provides access to the various settings and other
information. They will appear differently depending on whether the password security
feature is enabled. These menu items and their sub-menus will be covered in detail in other
sections of the manual.
The Meter displays the status and current data of the selected channel. In standard mode,
the unit displays up to two alpha isotopes of interest and the short-lived radon daughters:
Po-212, Po-214 and Po-218. Also the flow channel is displayed. In Radon-mode, the first
IoI will be replaced by the PAEC channel. The first line indicates the channel name with a
suffix character to denote the type of reading, Acute (/A) or Chronic (/C), which is followed
by a status, usually normal. The second line reports the current reading with the default unit.
The Log entry display in the lower half of the screen shows the readings for alpha channels,
logged once a minute. Each standard log entry lists the chronic reading, the minimum
detectable dose, the highest acute reading of that minute and the battery charge level. Other
log entries are listed as they occur. Possible log entry status conditions are high alarm, low
battery, flow rate failure, and other types of failures.
The Spectrum can also be viewed in the lower portion of the screen, in addition to the log
entry display, by tapping View—Spectrum… in the menu. The spectrum is displayed as a bar
graph made up of the detected counts. Each count is assigned to one of 256 channels,
increasing in energy along the non-visible X-axis. The Y-axis is a non-visible scale of counts
that compresses to fit the entire spectrum in view. The red line represents the mathematical
peak-fit curve that best matches the actual data. After several hours, three peaks will have
formed on the right end of the spectrum and illustrate the counts associated with the three
radon daughters.
The meter displays the various isotopes and variables being measured. To toggle the current
channel displayed, press the Channel button on the front of the unit. Repeated presses of
the Channel button will cycle through the channels, switching between acute and chronic
info before cycling to the next channel.
Changing the units displayed on the meter is done by hitting the Units button . This will
toggle through units of activity and concentration (e.g. pCi, cps, DAC-Hr, DAC). Each
Channel has its own set of four units, while the Flow channel only has one unit, LPM.
How to Change the Filter
After a Model 334A has been monitoring for some time, the filter will become laden with
dust and need to be replaced. Do this regularly; either by a specific schedule or when the
flow rate declines and indicates Lo Flow (see section 3 on configurations).

Replace the filter by removing the Filter Holder from the Detector Head and
discarding or storing the filter appropriately.

Lay the Back or Pump Side against the hole pattern on the Filter Holder.

If the pump is on , the filter will be suctioned to the Filter Holder and the back side
should not be visible.