TB 9-6660-270-50
the four-to-one ratio cannot be met, the actual accuracy of the equipment selected is shown
in parenthesis.
5. Accessories Required. The
accessories listed in
table 3 are issued as
indicated in
paragraph 4 above and
are used in this
calibration procedure. When necessary, these items
may be substituted by equivalent items, unless specifically prohibited.
Table 2. Minimum Specifications of Equipment Required
Common name
Minimum use
Manufacturer and model
Item
(official nomenclature)
specifications
(part number)
Haas, Model A1 modified
A1
BAROMETER
Range: 540 to 1085 mbar
1
(7913093)
(MERCURIAL
Accuracy: 0.5 mbar from
METRIC
540 to 745 mbar
BAROMETER)
0.4 mbar from
745 to 850 mbar
0.25 mbar from
850 to 925 mbar
0.15 mbar from
925 to 1085 mbar
0.002 in. Hg from
22 to 31.5 in. Hg
1Equipment
limitation: Accuracy: 0.014% of reading, 0.092 mm Hg (0.18 to 0.20 on 925 to 1085 mbar range); Range:
Maximum indication around 1057 mbar.
Table 3. Accessories Required
Common name
Description
Item
(official nomenclature)
(part number)
B1
MIS-10283
B2
NITROGEN PRESSURE KIT1 (TEST KIT, NITROGEN
7909189
PRESSURE)
B3
PRESSURE ACCESSORY KIT1
7913310
B4
PRESSURE REGULATOR
0 to 16 psi outlet (p/o 7910260)
B5
VACUUM PUMP
7915882
B6
VACUUM REGULATOR
P/o 7910260
1Secondary
transfer item.
SECTION III
6. Preliminary Instructions
a. The
instructions outlined in
paragraphs 6 and
7 are preparatory to the
calibration
process. Personnel should become familiar with the entire bulletin before beginning the
b. Items of equipment used in this procedure are referenced within the text by common
name and item identification number as listed in tables 2 and 3. For the identification of
equipment referenced by item numbers prefixed with A, see table 2, and for prefix B, see
3