(c) Using a glass funnel, slowly pour the
mercury in the well until the indicating level is at
approximately the zero graduation on the scale.
mounted on the laboratory right sidewall, above the Reid
(d) Replace the plug tightly.
vapor pressure bomb bath. The manometer is the
(e) Adjust the scale for the correct zero position
primary basic standard of pressure measurement. It is
in relation to the mercury meniscus.
used in the laboratory to calibrate the Reid vapor
pressure gages. It consists of a glass column supported
(5) For consistent results in reading the
within a frame and connected at the bottom by a U-
manometer, always observe the mercury meniscus the
shaped tube to the manometer fluid reservoir. It has a
same way. Always read the meniscus at eye level.
duplex-type scale calibrated in inches and tenths on the
2-27. Oxidation Stability Bath.
left side of the tube, pounds and tenths using mercury on
a. Description. The oxidation stability bath (fig.
the right side. It is also equipped with high pressure (HP)
to comply with the requirements
connection, low pressure (LP) connection, fill plug, drain
specified in ASTM Method D525 and D873 (TM 10-
plug, vent plug, and a zero scale adjustment knob.
1166). It is flush mounted on the right-hand countertop,
above cabinet P1 (fig. 1-2). The oxidation stability bath
(1) To measure pressure higher than atmospheric,
is used to determine oxidation stability of gasoline in
connect the line to the high pressure (HP) connection on
storage. The apparatus consists of an electrically heated
oxidation stability bath with a two-bomb capacity and
three-heat switch. It is provided with a wall-mounted
atmospheric condenser, two stainless steel bombs
(stored in drawer A4, fig.
B-7), provided with
Air pressure to the manometer must
not exceed 15 psi (6.8 kg/sq cm) (30
chemical resistant glass liner (stored in drawer C1, fig.
B-9) a wall-mounted two-pen type pressure recording
(2) To measure vacuum, connect the line to the low
gage with electric clock mechanism, and a range of from
pressure (LP) connection at top of indicating column.
zero to 200 pounds (90.8 kg/sq cm) in 2-pound divisions
(3) To measure a differential pressure, connect the
(.9 kg/sq cm) recording charts, and ink set; two 5 foot (1
line with higher pressure to the high pressure (HP)
5 m) lengths of flexible metal tubing with a coupler at
connection, and the line with lower pressure to the low
each end for connection between bomb and recorder;
pressure (LP) connection.
and a table socket to accommodate bomb when
(4) To fill the mercury reservoir:
tightening bomb cap.
(a) Remove the fill plug on the well.
(b) Vent the instrument on the low pressure side.
(1) Fill the bath to required height with water.
Assure zero adjustment at midscale.
(2) Insert the bombs in the bath.
(3) Insert the chart in the pressure recording gage
If a mercury spill occurs, do not
(para 2-28b. (1)).
vacuum or sweep the area. This will
(4) Apply power to the apparatus.
disperse mercury throughout the
(5) Proceed with the test according to ASTM
laboratory. Spills may be cleaned up
Method D525 and D873 (TM 10-1166).
by using a glass tube of about 6 cm
2-28. Pressure Recording Gage.
diameter drawn out to an opening of
a. Description. The pressure recording gage (fig.
about 1 mm and connected by rubber
to comply with the requirements
tubing to a filter flask connected with
specified in ASTM Methods D525 and D873 (TM 10-
a vacuum pump or aspirator, the
1166). It is mounted on the rear partition adjacent to the
flask acting as a trap. Control of
oxidation stability bath. The pressure recording gage is a
mercury vapor should not be
two-pen, disk chart, electrically powered (or spring
attempted with Flowers of Sulfur as
powered according to model in-
this is not effective. Spills must be
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