1. Product Bulletin 86
One Micromeritics Drive, Norcross, Georgia 30093
T. (770) 662-3620 www.micromeritics.com
TranSeal
for Vacuum-tight Sample Tube Sealing
The TranSealTM
allows you to retain vacuum on samples while transferring
them from the preparation station (or degas apparatus) to the analysis station.
It is designed to close and seal the sample tube when removed from the
preparation station and then to open automatically when fully installed on the
sample port.
The need to backfill with an inert gas is eliminated and so is the need for the
analysis system to evacuate the backfill gas. This is particularly advantageous
when working with microporous samples and fine powders. For microporous
samples, the backfill gas may diffuse into the micropores. A considerable
amount of time is required to remove this gas before analysis can begin. For
finely divided powders, the interparticle spaces become filled with gas. A
slow evacuation rate is required to avoid problems which may result from
fluidization of the sample as gas escapes from the powder bed*
. These time-
consuming tasks, sources of experimental error, and potential source of
maintenance problems are eliminated when using the TranSeal to transfer
the sample. The time saved from the evacuation process combined with the
time-saving advantages gained by using the instrument’s ‘entered free
space’ option can reduce by hours the total analysis time required by
some sample types.
The TranSeal is designed for use with 12.7-mm (1/2-in.) sample tubes for Micromeritics’ ASAP Series
instrument, TriStar 3000, and VacPrep 061 systems. Its leak (permeation) rate against atmospheric
pressure is better than 1.6 x 10-3
Std cm3
/hr.
*
When a powder bed aerosolizes, some powder particles may rise to the upper regions of the sample tube and
become affixed to the walls. These particles may be out of the ‘cold zone’ of the sample tube and will undergo
adsorption at a higher temperature than the fraction that remains in the cold zone. Fluidizing the sample bed also
provides the potential of drawing particles into the manifold causing contamination problems until the manifold is
properly cleaned.
TranSeal
The TranSeal is inserted into
the sample tube to provide a
vacuum-tight seal.
2. Product Bulletin 86 Page 2
Rev 6/01
How It Works
The TranSeal is inserted into the sample tube after the sample is in place. An O-ring provides sealing with
the inside of the sample tube. The O-ring can be placed in one of three grooves, ensuring a tight seal over
a range of inside tube diameters that may be encountered with 12.7-mm sample tubes. The TranSeal
contains a plunger held against the seal with a compression spring. Pressure on the cap of the TranSeal
opens the valve, forcing the plunger downward. The plunger protrudes slightly into the sample tube when
the TranSeal is in the open position.
A special sample port retaining nut is included in the TranSeal kit. This retaining nut is of a lower profile
than the one supplied with the ASAP Series and VacPrep 061 instruments; the TriStar 3000 already uses
the low-profile nut. The low-profile nut enables you to view the stem of the TranSeal when open
(protruding into the tube). The TranSeal is open when it is fully installed onto the sample port. The seal
can be closed by loosening the retaining nut slightly and pulling the sample tube down a short distance,
just enough to see the stem disappear. This sealing occurs prior to the port seal being broken so that no
atmospheric exposure occurs.
Ordering Information
201-33026-00 TranSeal Kit; includes three TranSeals, three low-profile retaining nuts, three split
ferrules, three retaining rings, and assembly instructions
300-25862-00 TranSeal only
