TB 9-5210-210-50
SECTION I
IDENTIFICATION AND DESCRIPTION
This bulletin provides instructions for the
1. Test Instrument Identification.
calibration of Dial Indicators (MIL-I-18422). The manufacturer's instruction manual was
used as the prime data source in compiling these instructions. The dial indicators will be
referred to as the "TI" test instrument throughout this bulletin.
a. Model Variations. Variations among models are described in text.
b. Time and Technique. The time required for this calibration is approximately 0.5
hour for each TI using the physical technique.
2. Calibration Data Card, DA Form 2416. Forms, records, and reports required for
calibration personnel at all levels are prescribed by TM 38-750. DA Form 2416 must be
annotated in accordance with TM 38-750 for each calibration performed.
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
Style1
A
Spindle, parallel to dial
B
Spindle, right angle from back dial.
C
Universal, adjustment contact point.
Type1
1
1/10000 (0.0001) inch graduations
2
5/10000 (0.0005) inch graduations
3
1/1000 (0.001) inch graduations
4
5/100000 (0.00005) inch graduations
Accuracy
1 graduation at any point within the range of the indicator except type I
long range indicators (more than 2 1/3 revolutions) shall be 1 graduation
within the first 2 1/3 revolutions and 5 graduations at any point beyond
2 1/3 revolutions
Repetition
1/5 graduation of readings.
1This
specification is for information only and is not verified in this bulletin.
SECTION II
EQUIPMENT REQUIREMENT
4. Equipment Required. Table 2
identifies the
specific equipment used in
this
calibration procedure. This equipment is issued with the secondary transfer calibration
standards set and is to be used in performing this procedure. Alternate items may be used
by the calibrating activity when the equipment listed in table 2 is not available. 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 specifications
listed in table 2. The accuracies listed in table 2 provide a four-to-one accuracy ratio
between the standard and TI. Where the four-to-one ratio cannot be met, the actual
accuracy of the equipment selected is shown in parenthesis.
2