SECTION II. OPERATIONS OF THE TESTER

TM 55-4920-378-14&P

Operations of the Tester

SECTION II

OPERATIONS OF THE TESTER

WARNING

Do not operate the tester unless all access panels are in place: Injury could result from the

shattering of the glass reservoir or other malfunction of the tester.

2-1. GENERAL.

The tester can be utilized as a two-fold purpose:

a. To test other indicators of equivalent pressure and vacuum.

b. To test out tbe pitot static system of the aircraft.

2-2. OPERATION PROCEDURES.

To operate, the following procedures must be followed:

a. Set the tester on a level bench or platform. Check to see that the oil level in the reservoir is at the correct height. If the

oil level is not at the correct height, fill by viewing through window (Figure 1-1, Ref. 16), in accordance with maintenance

procedure, paragraph 3-2. Before connecting to the desired power source be certain that the "ON/OFF' switch (4) is in the

"OFF" position, control valves (2 & 3) are closed and the two sector valves (1 and 17) on the front instrument panel of the

tester are in the "OFF' position. You are now ready for testing.

b. If you are going to use pressure, then be sure at this point both the vacuum control valves (3) are opened. If you are

going to use vacuum to test, be sure both the pressure control valves (2) are open. Move the selector valve (1 and 17) to the

marking shown for the instrument you wish tested. Be sure that both control valves (2 & 3) of the specific selector are closed.

c. To test a specific instrument, plug into the desired instrument outlet (7) from the rear of the case as marked and open

one of the valves (9) at the top of the test set for the specific instrument you wish tested. Turn the "ON/OFF" switch (4) to

"ON" which will start the pump running.

d. Open, with a very slight turn, the "UP" valve of your selected pressure (2) or vacuum (3) and the instrument will start in-

dicating for you. See Table 2-1. To get true readings for the instrument you are testing, set the master instrument to the cor-

rected reading as shown on the correction card (10) for each instrument. You can proceed all the way up to the top of the

scale and then return to zero by shutting off the "UP" valve and opening the "DOWN" valve. This test or method of operation

can be repeated with all instruments of the type shown in Table 2-1.

It should be noted at this point, that each one of the instruments on the test panel has a safety overload and that it is impos-

sible to damage any of the instruments by exerting too much pressure or vacuum to the specific instruments. However, it

should be pointed out that a maximum reading of 5,000 feet per minute, "UP" or "DOWN", should be used on the rate of

climb. The tester comes with all the necessary tubing and lines to connect directly to aircraft instruments or to connect to a

pitot system or a static system. See Table 1-1. Upon completion of any and all testing, be sure that both selector valves (1 and

17) are in the "OFF" position and that both sets of valves (2&3) operating pressure and vacuum are closed.

2-1