Section II CALIBRATION INSTRUCTIONS

TM 5-6640-213-14

Section II.

CALIBRATION INSTRUCTIONS

CALIBRATION LEVELS AND REFERENCES.

3-20.

a. Calibration requirements for test equipment requiring A-level

calibration in this laboratory can be identified by reference to TB

750-236 under the following appropriate TB's.

(1) Weight set class 5 (5mg to 50gm)

TB 9-6670-254-50

(2) Pressure gage (0-5 lb).

TB 9-6685-319-50

(3) Thermometer (ASTM certified)

TB 9-6685-314-50

(4) Hydrometer

TB 9-6630-201-50

(5) Multimeter

TB 9-6625-961-50

b. The calibration procedures and requirements given in this

section are identified for the aviation fuel surveillance laboratory

as C-level requirements and will be performed by qualified laboratory

personnel assigned to this laboratory.

3-21.

ANALYTICAL BALANCE.

The analytical balance provided is a single arm instrument. It

has weighing capacity of 100 grams. When provided with the manual

taring accessories, the weighing capacity is increased to 150 gm.

The precision (standard deviation) of the balance is + or - 0.05

milligrams (mg), digital redability is 0.1 mg, and accuracy in the

optical range is + or - 0.05 mge ASTM E-319 procedures are recom-

mended for evaluating performance and verifying the accuracy of the

balance. These procedures determine the precision with which balance

can compare known weight loads; i.e., the built-in weights of the bal-

ance and a known weight load. Section 5, ASTM E-319 outlines proce-

dures for preparation of the balance for evaluation, and section 8

outlines procedures for evaluating balance accuracy. Ap precision

weight set (class S) must be used to evaluate balance performance.

The verification evaluation of the balances are performed by operating

ersonnel. The double beam balance may be evaluated using the above

procedures. The standard deviation of the double balance is + or -

0.1 gm.

3-22.

REID VAPOR GAGES (RVP).

The RVP gages msut be verified for accuracy after each test when

vapor pressure of motor gasolines is being determined. When deter-

mining the vapor pressure of aviation fuels (aviation gasoline and

turbine engine fuel) the gage must be verified for accuracy before

and after each test by operating personnel. The accuracy of RVP

gages is verified by using the manometer. When the gage reading and

the manometer reading differ by 1 percent or less, the gage is

considered accurate; i.e., the gage correction factor must not be

greater than 0.05 psi for O to 15 pound gages or 0.15 psi for O to 15

pound gages. If the readings differ by more than 1 percent the gage

is considered inaccurate and must be repaired or replaced.

3-39