 |
|||
|
Page Title:
Standard atmospheric conditions |
|
||
| ||||||||||
|
|  MIL-T-26219A
4.5 Test conditions.
4.5.1 Standard atmospheric conditions. Whenever the pressure and
temperature existing at the time of he test are not specified definitely, it
is understood that the test is to be made at atmospheric pressure
(approximate y 29.92 i riches Hg) and at room temperature (approximately
+25C). When tests are made with atmospheric pressure or room temperature
differing materially from the above values, proper allowances shall be made
for the difference from the specified condition.
4.5.2 Master rotational speed indicating system. A master rotational
speed indicating system shall be used for checking the accuracy of the digital
The master indicating system shall be
speed indicator of the test set.
capable of providing measurement accuracies of + 1.0 revolution per minute and
0.02 percent rpm.
Unless otherwise specified, the test set will be tested in
4.5.3 Attitude.
the normal operating position.
4.6 Test methods.
4.6.1 Examination of product. Each test set shall be inspected to
determine compliance with t he requirements specified herein with respect to
dimensions, material, workmanship, and marking.
4.6.2 Operation at room temperature.
A transducer, capable of providing
output signals for the master rotational speed indicating system, shall be
attached to the tachometer generator mounting pad on the control panel and
electrically connected to the master rotational speed indicating system. The
test set shall be connected to a 115V, 400 cycle single phase power source.
The test set and the master rotational speed indicating system shall be
electrically energized. The variable speed drive control of the test set
shall be rotated until the digital indicator of the test set registers
approximately 4200 rpm. The test set shall be allowed to warm up under this
o crating condition for a period not to exceed 5 minutes.
Immediately after
the warmup period, the accuracy of the digital speed indicator of the test set
shall be checked at the test speeds specified in Table I by means of the
master rotational speed indiating system. The readings registered by the
digital indicator shall not differ respectively from the readings registered
by the master rotational speed indicating system by more than the tolerance
specified in Table I.
During the accomplishment of this test, it shall be
noted that the controls and switches are easy to operate and the variable
speed drive is capable of maintaining the output speed at the specified test
points sufficiently constant to result in steady indication of the digital
speed indicator. Upon completion of the above, a Type E-30 tachometer
indicator conforming to MIL-I-25686, or any other tachometer generator
approved by the acquiring activity, shall be electrically connected to the
"generator output" receptacle by means of adapter "B" shown on Figure 4,
14
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals