TB 9-5210-221-40
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Bench Level, L. S. Starrett, Models 98, 98-6, 98-8 and 98-12. The
manufacturers' manuals were used as the prime data sources in compiling these
instructions. The equipment being calibrated will be referred to as the TI (test instrument)
throughout this bulletin.
a. Model Variations.
Variations among models are described in text, tables, and
figures.
b. Time and Technique. The time required for this calibration is approximately 1
hour, using the physical technique.
2. Forms, Records, and Reports. Forms, records, and reports required for calibration
personnel at all levels are prescribed by TB 750-25.
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Table 1. Calibration Description
Test instrument parameters
Performance specifications
Main level vial
Range: 0.005 inch per 12 inches
Accuracy: 1/4 division of vial
Cross test vial
Range: N/A
Accuracy: 0.005 in.
EQUIPMENT REQUIREMENTS
calibration procedure. This equipment is issued with Secondary Reference Calibration
Standards Set, NSN 4931-00-621-7878. Alternate items may be used by the calibrating
activity. The items selected must be verified to perform satisfactorily prior to use and must
bear evidence of current calibration. The equipment must meet or exceed the minimum use
between the standard and TI. Where the four-to-one ratio cannot be met, the actual
accuracy of the equipment selected is shown in parentheses.
5. Accessories Required. The accessories required for this calibration are common
usage accessories issued as indicated in paragraph 4 above, and are not listed in this
calibration procedure.