TB 9-5210-205-40
Table 3. Accessories Required - Continued
Common name
Description (part number)
POLISHING CLOTH
Cotton, batiste, white, 4 x 6 inch (7920-263-2765)
Lay flat, Fed Spec L-F-378b. Packaging aids Corp.
1
Stock numbers, 1CT, 11/2CT, 2CT, and 21/2 CT
POLYETHYLENE TUBING
SCISSORS
6- or 8-in. size
SOLVENT
Mineral spirits
TAPE
Pressure sensitive masking tape (PPP-T-60)
1
WOODEN TRAY
15 x 10 x 3/4 in.
1Procure
locally.
CALIBRATION PROCESS
6. General Information
a. Acceptance Convention
(1) Tolerances for surface finish, flatness, parallelism, and size will be within those
specified for gage blocks and accessories found in table 1.
(2) Optical flats with a monochromatic light or interferometer may be used for
flatness tests. Refer to figure 1 for interpretation of fringe lines for allowable tolerances.
b. Requirements for Calibration Interval Extension of Non-used Gage Blocks.
To reduce the quantity of gage blocks being recalibrated without adversely affecting
accuracy, adhere to the following requirements:
(1) Positive evidence of non-use. At the end of the calibration cycle, blocks that
remain sealed in polyethylene display positive evidence of non-use.
(2) The calibration interval will not be extended beyond 6 years from the date of
sealing for those gage blocks which are unused (sealed). A statement of the date of initial
sealing will be completed and retained with calibration worksheets.
NOTE
Gage blocks that are reserved for use as reference standards
for calibration of other gage blocks need not be sealed.
7. Preliminary Instructions
a. The instructions outlined in paragraphs 7 and 8 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by
common name.
