PrecisionTM Instruction Manual
These instructions encompass the high temperature Bronze Block Gum Baths listed below with their specific
The Gum Baths are designed to determine existent gum in motor gasoline, aviation gasoline, and turbine fuels, in
accordance with ASTM D381 (1P-131).
WARNING: Gasoline and aviation fuel are extremely flammable and adequate ventilation should
be provided during the test. (See the Annex in ASTM D-381; Al, Precautionary Statements For
Additional Caution, Warning, and Danger Explanations.)
Test Method Confirmance:
Air Flow Indication:
0 to 5 psig,
graduated in one oz. divisions.
Uniformity at 329F (165C):
5F ( 3C) each well.
Location: The most uniform operating conditions and results will be obtained by placing the unit in an area remote from
drafts, ventilating outlets, radiators, and other rapidly changing ambient conditions.
(Please read carefully.)
CAUTION: Be sure the power supply is of the same voltage as specified on the nameplate.
The Gum Bath is supplied with a terminal block located on the bottom of the bath and must be permanently connected to
an electrical source by a qualified electrician.
WARNING: National Electrical Code should be observed for proper fusing and the size of the
service wires. For personal safety, this apparatus must be properly grounded.
Air or Steam Connections: All connections should consist of at least 1/2" pipe and unions. This size has been designated
to insure an adequate volume of air or steam being admitted to the bath. The rate of flow required is 1 liter per second,
5%, and is determined by the flow/pressure gauge provided with this unit, as specified by ASTM D-381.
This flow/pressure gauge has been properly marked and calibrated in pounds and ounces, corresponding to the flow of
air in liters per second. Calibrate according to description in ASTM D-381.
Note: A flowmeter reading of 600 mL/s for each outlet on a flowmeter calibrated at room temperature and atmospheric
pressure will ensure delivery of 1000
150mL/s at the temperature of 155
5C (311 + 9F), provided the pressure on
the outlet of the flowmeter is not greater than 5 psi (34.5 kPa).