Section III. SAMPLING AND TESTING

TB 55-1500-334-25

Section III. SAMPLING AND TESTING

Carefully insert tubing into reservoir. Do not allow the

3-1. General.

tube to touch the sides or bottom of the reservoir when

taking a sample.

Fluid samples are taken from

Hydraulic fluid, MIL-H-83282 loses its fire

approximately the same depth in the reservoir each time.

resistant properties rapidly if it is diluted with more than 3

percent by volume of MIL-H-5606 hydraulic fluid. Mixing

CAUTION

of the two hydraulic fluids requires determining the flash

point of the resultant mixture. The flash point should be

no lower than 3800F. This section covers sampling and

Do not drop tubes or

sampling

testing procedures.

equipment Into reservoir.

3-2. Sampling Techniques.

(5) Allow the tube to fill with fluid.

a. Methods of Sampling. Take fluid samples

CAUTION

from hydraulic systems for flash point testing. Use one of

the following methods:

Do not use mouth suction.

(1) Use the tubing method to sample the

(6) Place a finger over the top of the tube

reservoir, provided that the reservoir is a part of the

blocking the hole and withdraw the tube from the

circulating system.

reservoir. The tube will be partially filled with fluid.

(2)

Drain the sample from the filter

(7) Insert the bottom of the tube into the

housing.

sample bottle, then release the fluid by removing the

finger from the top of the tube.

(3) Drain the sample from a line that

circulates fluid. Be careful while disconnecting the line in

(8) Repeat, until the fluid sample bottle is

order to avoid contamination of the fluid.

filled to a height of 2-1/2 inches from the bottom.

b. Preferred Method. The use of plastic flexible

(9)

Replace and tighten the cap on the

tubing for obtaining oil samples is the preferred method

sample bottle.

and will be used whenever possible. (See para 3-3.) The

tube is used to take samples through the hydraulic system

(10) Replace the tank filler cap or other

filler neck or through the dipstick hole. Samples obtained

access covering and discard the sampling tube.

by this method are less likely to contain sludge and dirt

than drain samples. The procedure is as follows:

c. Labeling. The following information should

accompany the hydraulic fluid sample. Secure this

(1) Obtain a sample bottle and sampling tube of

information to the sample bottle with a rubber band.

proper length and diameter for each assembly.

(1) Type aircraft and serial number.

(2) Remove the filler cap or dipstick from the

hydraulic fluid reservoir.

(2)

Hydraulic system from which sample

was taken.

(3) Place sample bottle cap on a clean surface

with edges up to keep them clean.

(3) Date on which sample was taken.

(4) Cut both ends off sample tube if it has fused

(4)

Return

address

and

AUTOVON

ends or remove protective end caps.

contact.

3-1