Standard Test Method for Density, Relative Density, and API Gravity of Crude Petroleum and Liquid Petroleum Products by Thermohydrometer Method

A thermohydrometer (a hydrometer with an integrated thermometer) is immersed directly into the sample.

• The instrument floats in the liquid.
• The immersion depth gives the density reading.
• The built-in thermometer simultaneously measures sample temperature.
• The observed value is corrected to a reference temperature (usually 60°F / 15°C) using petroleum measurement tables 

This method is particularly suitable for on-site field measurements (e.g., tanks, pipelines, custody transfer).

This test method covers the determination, using a glass thermohydrometer in conjunction with a series of calculations, of the density, relative density, or API gravity of crude petroleum, petroleum products, or mixtures of petroleum and nonpetroleum products normally handled as liquids and having

Condition is a Reid vapor pressures of 101.325 kPa (14.696 psi) or less. Applications are crude oil tank measurements, refinery process control, custody transfer, pipeline quality verification or marine terminal operation.

The method offers simple measurement and direct temperature measurement. It is faster than the pycnometer method. The advantage over ASTM D1298 is that it not uses a separate thermometer.

An overview of the ASTM density methods can be found here Density table

The Tamson ASTM D6822 apparatus is available in the following voltages/frequencies:

• Tamson ASTM D6822 230V/50Hz (P/N: 00T2000)
• Tamson ASTM D6822 230V/60Hz (P/N: 00T2001)
• Tamson ASTM D6822 115V/60Hz (P/N: 00T2002)

See tab "More Information" for the specificationsheet and manual