Volumetric

TM 9-4931-456-14-1

the viscometer with the test fluid, according to the

cleaned and refilled with clean fluid. Failure to perform

manufacturer's instructions. If the viscometer is not

this inspection could result in damage to the standard

filled correctly, the viscosity value determined will be in

flowmeters.

error. Place the charged viscometer and thermometer

E.5 Volumetric

(AG, table E-l) in the viscometer bath (B1, table E.1)

Operate the test instrument prior to insertion of the

an(d set the bath control to the test fluid operating

standard flowmeters. Determine the correct valves for

temperature recorded on the data sheet. Following the

controlling flow rate to the test instrument flowmeter and

manufacturer's instructions, determine the viscosity of

close the valves. Determine the volumetric flowrate

the test fluid in centistokes. Record this value on the

range of test instrument and select the appropriate size

flow data sheet.

standard flowmeter.

Divide the average standard flowmeter frequency for

Install the correct size standard flowmeter in line with

each test point on the test instrument by the viscosity to

the test instrument, being careful not to cross thread the

determine a value for F/V and record these values (F/V

meter. Insure that the direction flow arrow on the

is the standard flowmeter viscous influence factor).

standard flowmeter is pointing in the correct direction.

Refer to the calibration table supplied with each

The flow straighteners are to be installed in their correct

standard flowmeter, determine and record a C value for

position and the thermometer (A5, table E.1) is to be

each F/V value. Multiply each of the C values by their

installed, in line, upstream of the standard flowmeter.

associated frequency to obtain flowrate in gallons per

The filter is to be installed upstream of the standard

minute (gpm)n. The following equation applies for this

flowmeter. Connect the standard flowmeter to its flow

calculation: GPM = C x F, where C is the calibration

indicator and allow sufficient time for the instrument to

factor for the flowmeter and F is the output of the

warm up. Refer to the manufacturer's manual for the

flowmeter in cycle. per second. If the test instrument is

correct operating procedure for the flow indicator.

scaled in volumetric units other than gpm, approximate

Select ten approximately equally spaced calibration

conversions must be made to generate compatible

points at cardinal divisions through the range of the test

units.

instrument. Record the selected values in column 1 on

E.6 Mass Flow

the flow data sheet (table E.2). Allow four lines for each

Perform E-5 to obtain the volumetric flow units for the

calibration point selected.

test instrument.

Initiate operation of the fluid source (test stand, etc.) and

Collect a sample of fluid from the test stand and

open the bypass line until the fluid temperature

measure its specific gravity with the correct range of

stabilizes at the desired test temperature (this

hydrometer from the hydrometer set (A3 or A4, table

temperature will probably be etched on the test

E.1). Determine and record the temperature at which

instrument scale or its readout device). If no bypass line

the observed specific gravity is measured with (A6, table

is available, the flowmeter should be removed until the

E.1).

Refer to table 23 of the API Petroleum

temperature is stabilized. After the temperature has

Measurement tables and determine the specific gravity

stabilized, close the bypass valve and slowly open the

of the test fluid at 60 /60 F by entering the table with

flow control valve until the lowest test point is reached.

the previously observed specific gravity and the

Allow the temperature of the system to restabilize before

observed temperature. Record this value.

taking readings.

Refer to table 24 of the API Petroleum Measurement

Record the fluid temperature and the standard

tables and determine the volume reduction factor for the

flowmeter's frequency in the appropriate flow data sheet

test fluid. This is performed by entering the tables with

columns. Take three frequency readings at this flowrate

the specific gravity at 60o/ 60o F and the temperature at

setting on the test instrument and average the data.

which the flowrate measurements were made. Record

Repeat the procedure of the preceding paragraph above

this value. If the temperature changed during the

for each of the ten selected cardinal points on the test

calibration, a volume reduction factor must be obtained

instrument flowmeter. Record all data. Collect a

and recorded for each temperature.

sample of the fluid from the test stand in a clean

Perform the following calculation: Specific gravity at

container. Select the correct viscometer from the

operating temperature = specific gravity at 60o/ 60o F

viscometer set (A2, table E-1). The approximate fluid

volume reduction factor. Record these values in column

viscosity is usually etched on the test instrument. Fill

E-2