PART B - CHECKING PROCEDURES USED TO OBTAIN THE
TEMPERATURE OF PETROLEUM PRODUCTS
Temperature Measurement. Because the volume of petroleum products increases or decreases in
direct proportion to temperature increase and decrease, accurate measurement of the temperature of a
product must be taken at the time of gaging. The measured quantity must be corrected to the standard
temperature of 60F for volumes over 3,500 gallons. When gaging large quantities, take temperature
readings at various levels and average them to determine the true average temperature of the product.
Table 3-1 of FM 10-67-1 (Page 3-20) shows the number of readings necessary and the levels at which tank
thermometers should be placed.
Measuring Instrument. The cup-case thermometer (refer to Fig. B-1) is used to measure the
temperature of a product in storage tanks. The thermometer is attached to a hardwood backing with the
base of the mercury column extending into the cup case. The cup case, when filled with liquid under
measurement, minimizes fluctuation of the reading when the thermometer is suddenly withdrawn from the
tank. The minimum immersion time for the cup-case thermometer in various petroleum products is given in
Table 3-2 of FM 10-67-1 (Page 3-20). To avoid the long immersion time required for measuring the
temperature of heavy fuel oils, it may be practical to leave thermometers suspended in the tanks at all times.
Fig. 4-4. Cup-Case Thermometer
Measuring Procedures. To measure the temperature of petroleum products in storage tanks, the
following procedures are used:
The thermometers are inspected for separation of the mercury column, and any faulty thermometers are
replaced. Separation of the mercury column results in incorrect readings. Each thermometer is checked