DIRECT SUPPORT TESTING PROCEDURES
peak value equals 2.83 times the voltmeter value;
conversely, the voltmeter value equals 0.353 times
a. Scope. This chapter contains testing proce-
the peak-to-peak value.) When an oscilloscope is
dures to be used by direct support maintenance
not available, an electronic voltmeter may be sub-
personnel to determine whether repaired equip-
stituted if allowance is made for the difference in
ment is performing satisfactorily for return to
i n d i c a t i o n s (rms versus peak-to-peak) as de-
b. Test and Procedures. Tests are limited to
c. Equipment Warmup and Connections.
those that can be performed with the tools, test
(1) Before taking any measurements, allow
equipments, and materials allocated to direct sup-
the equipment to warm up for at least 30 minutes
port maintenance. Tests and procedures are on
with the power switch at STAND BY.
charts preceded by a list of test equipment and
(2) Adjust the operating controls to permit
material required, and by instructions for setting
optimum operation of the equipment.
up and interconnecting the test equipment.
(3) With the signal and power cable assem-
c. Performances Standards. Performance stand-
bly (Special Purpose Cable Assembly W601), in-
ards are included in each chart to provide a direct
terconnect jack J101 on the recorder, Frequency
go-no-go basis on which the tester can reject or
Standard TS-65C/FMQ-1, and a convenient 60-
pass the repaired equipment.
Hz power outlet. When making the connections to
the frequency standard, the black lead is con-
nected to the ground (lower) terminal and the
5-2. Standard Test Conditions
white lead to the signal terminal.
a. Test Equipment. Test equipment ordinarily
(4) Room temperature and humidity condi-
consists of Frequency Standard TS-65C/FMQ-1
tions must be normal and reasonably constant.
(as a signal source), Oscilloscope AN/USM-140
(5) Line voltage and frequency must be nor-
(as an indicating device), and a stopwatch. Also
mal and constant (115 volts (approximately) and
used is a radiosonde unit having a regulated out-
put to simulate specific temperature, humidity, and
pressure conditions for dynamically checking the
accuracy of the Radiosonde Recorder AN/
5-3. Chart Feed Test
TMQ-5(*) data print.
The chart feed test measures the number of graph
line spaces that the chart travels in 5 minutes.
b. Alternate Test Equipment. If Oscilloscope
A N / U S M - 1 4 0 is not available, any test scope
a. Test Equipment and Materials. A stopwatch
capable of accepting, without overloading, input
is required for this test.
voltages of 40 volts (root mean square) or higher
b. Test Connections and Conditions. No special
can be used. If the test scope has no vertical cali-
connections are required. The prime power source
brator, then it must be calibrated by a reasonably
should supply 110 to 125 volts at exactly 60 Hz as
accurate voltmeter and an adjustable source of
indicated on the control panel meters. Check the
60-Hz voltage. This calibration should be continu-
number of speeds in the following procedure as
ous between zero and 115 volts peak-to-peak, or 40
applicable to the unit being tested.
volts rms. (For sine wave shapes, the peak-to-