Standard Test Method for API Gravity of Crude Petroleum and Petroleum Products.

ASTM D287 is the hydrometer method for determining API gravity of crude petroleum and liquid petroleum products. These are typically those handled as liquids and with Reid vapor pressure ≤ 101.325 kPa

A glass API hydrometer floats in the sample. The depth of immersion depends on the liquid’s density, and the stem is graduated to read degrees API.

A sample is brought to a uniform temperature in the hydrometer cylinder. The TLC15 is used to keep the sample at constant temperature

A hydrometer is inserted in the sample and read  where the liquid surface cuts the hydrometer scale. The temperatue is read when stable within ± 0,5°C.

If opaque-liquid procedure was used, subtract the determined meniscus correction from the observed reading. Apply required corrections noted by the standard (commonly including meniscus, thermal glass expansion, and any alternate calibration temperature effects, as applicable). The reading than is converted to the reference temperature 15.56 °C / 60°F using the appropriate tables.Bovenkant formulier

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

The Tamson ASTM D1298 apparatus is available in the following voltages/frequencies:

• Tamson ASTM D287 230V/50Hz (P/N: 00T2000)
• Tamson ASTM D287 230V/60Hz (P/N: 00T2001)
• Tamson ASTM D287 115V/60Hz (P/N: 00T2002)

See tab "More Information" for the specificationsheet and manual