OPERATING CONTROLS.

TM 55-4920-416-13

Section IV

NAVAER 17-15C-539

Paragraphs 4-5 to 4-10

4-5. OPERATING CONTROLS.

4-8. VACUUM AND PRESSURE CONTROL VALVES (3, 4, 5,

and 6, figure 4-1). These valves are set up in pairs, one pair

4-6. VACUUM SELECTOR (1, figure 4-1). The vacuum

controls the vacuum level in the test set, while the other pair

selector functions as a single control manifold and as such,

controls the pressure level. One valve of each pair controls the

sets up various vacuum-pressure systems (as shown in

increase of vacuum or pressure while the other valve causes a

figure 1-5) required to test and/or calibrate certain types of

decrease. These are precision valves and are designed to

aircraft instruments.

The particular vacuum-pressure

permit very accurate control of vacuum or pressure.

configurations are dependent on the position of the selector.

4-9. MASTER INSTRUMENT CASE LEAK TEST VALVES (1,

4-7. PRESSURE SELECTOR (2, figure 4-1). The pressure

2, 3, 4 and 5, figure 4-2). The master case leak test valves are

selector, as in the case of the vacuum selector, also acts as a

not used in the normal operation of the test set, but are

single control manifold and as such sets up various vacuum,

provided for checking the master instruments for case leaks or

pressure and vacuum-pressure systems (as shown in

recalibration of the master instruments without removing them

figure 1-5) required to test and/or calibrate certain types of

from the test set.

aircraft instruments. The particular configuration is dependent

on the position of this selector.

4-10. POWER SWITCH (7, figure 4-1). This switch applies

power to the motor of the pump, and an indicator lamp

1. Rate-of-Climb and Altimeter

3. Airspeed Calibrated Case Leak

Case Leak Test Valve

Test Valve

2. Airspeed Case Leak Test

4. Manifold Pressure Case Leak

Valve

Test Valve

5. Fuel Pressure Case Leak Test Valve

Figure 4-2. Case Leak Test Valves

I U.S. GOVERNMENT PRINTING OFFICE: 1991 - 554-047/21059

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