TB 9-6680-286-35
IDENTIFICATION AND DESCRIPTION
1. Test Instrument
Identification.
This bulletin provides instructions for the
calibration of Centrifugal Hand-Held Mechanical Tachometer (General).
The
manufacturer's manual was used as the prime data source in compiling these instructions.
The equipment being calibrated will be referred to as the TI (test instrument) throughout
this bulletin.
a. Model Variations. None.
b. Time and Technique. The time required for this calibration is approximately 1
hour, using the physical technique.
2. Forms,
Records, and
Reports
a.
Forms, records, and
reports required for calibration personnel at all
levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which
they appear. When adjustments are in tables, the (R) follows the designated adjustment.
Report only those adjustments made and designated with (R).
3. Calibration
Description. TI
parameters and
performance specifications which
pertain to this calibration are listed in table 1.
Test instrument parameters
Performance specifications
RPM
Low range: 50 to 500 RPM (increments of 2)
Medium range: 500 to 5000 RPM (increments of 20)
High range: 5000 to 50,000 RPM1
Accuracy: 2% of FS
1TI
calibration/verification limited to 10,000 RPM due to standard limitations.
EQUIPMENT REQUIREMENTS
4. Equipment
Required. Table 2 identifies the
specific equipment to be
used in this
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Set AN/GSM-287 or AN/GSM-705. 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 specifications listed in table 2. The accuracies listed in table 2 provide a four-
to-one 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.