API Gravedad - Informe de aplicación del densímetro
Comprender la gravedad de la API:
Gravedad API - El petróleo crudo es una materia prima indispensable para todo tipo de productos y otros combustibles, aceites y lubricantes. La caracterización de estos productos es muy compleja y a menudo poco práctica. Por ello, las mediciones de propiedades más sencillas, como el punto de inflamación, la presión de vapor y la viscosidad, se han convertido en procedimientos estándar de análisis químico en casi todos los laboratorios petrolíferos. De todas estas mediciones, la densidad se ha convertido en una de las propiedades físicas más importantes y de uso más frecuente en la industria petrolera.
Medir la gravedad API
The API Gravity (American Petroleum Institute) is a value that is supposed to make it easier to compare one hydrocarbon to another. The determination of API Gravity is done in an exact manner as prescribed and detailed in ASTM D-1250.
In the United States, API Gravities are usually determined at 60 ºF, whereas in Europe and other parts of the world, it is more common to use 15 ºC and/or 20 ºC. The DDM 2911 Automatic Density Meter may be controlled to bring the petroleum product to any of these temperatures and make the required measurement. However, for the more viscous hydrocarbons, the density is often measured at some elevated temperature, and this value is then used to mathematically correct back to the proper API Gravity value for the lower temperature. This mathematical calculation is done using Volume Correction Factors (VCF). Each different type of petroleum product group has a different VCF.
The historical method for the measurement of API Gravity has been the hydrometer. However, the low precision of the hydrometer as the prices of crude oils increase makes this method obsolete. Additionally, the large sample volume required, the large quantities of solvents needed for the cleaning of the hydrometer column, and the need for a dozen or more different hydrometers to cover the entire API range has made using this method completely impractical in today’s petroleum laboratories.
Uso del densímetro Rudolph Research DDM 2911 para medir la gravedad API
The DDM 2911 Density Meter provides the fastest, most accurate, and easiest means for the measurement of API Gravities. The API Gravity software that is built-into the DDM 2911 makes the use of external tables unnecessary. The measurement results are displayed on the large 10.4 inch digital color screen, and the results may be saved locally or saved to your server. Results can also be printed out on any printer that is on your network. Further, the printouts may be customized and used as your certificates of analysis. Numerous and simultaneous results can be calculated. For example, the API Gravity at 60 ºF, 15 ºC, and 20 º, C along with the results at these same temperatures for density and specific gravity, may all be determined in one simple and fast measurement.
Multiple measurements made on the same sample can also be made automatically, and the statistical results can be calculated with the final results.
The sample size is small; typically, 1 to 2 ml is all that is required. The subsequent cleaning of the sample is easy and also requires a small amount of solvent. The DDM 2911 Density Meter is robust and requires very little maintenance. All wetted parts are corrosion-resistant and not affected by the chemicals and solvents used in this industry. Measurements are fast, normally requiring 2 to 3 minutes per sample.
The simple operation makes it easy to train lab personnel in its use. The DDM 2911 operates in a familiar Windows® environment, making the navigation through the various menus intuitive and easy to do without the need for studying the manual. And if the manual is needed, it’s found in the DDM 2911 32GB memory! The availability of having 3 USB ports and a Cat 5 cable connection will become indispensable for communication and adding of peripherals as needed for an efficient and up-to-date laboratory.
The most common source of error in measurements using digital density meters has been made easy to eliminate with the intelligent design of the DDM 2911. Rudolph Research Analytical’s exclusive VideoView™ ensures that your sample is bubble-free for the most accurate and reproducible results. Bubbles can now even be seen in dark and cloudy samples.
Certified liquid density standards come with each DDM 2911, making it easy to validate the accuracy of your density meter. Calibration checks can be developed and customized to meet the specific requirements of your laboratory.
Rudolph Research Analytical’s optional auto-sampler, the ASX 1400, may be utilized with any of our Density Meters and permits the measurement, cleaning, and drying of up to 240 samples per run. Our pressurized filling method ensures that light-end hydrocarbons are not pulled off as would happen with auto-samplers using a suction mode.
ASTM, ISO y DIN - Normas industriales:
ASTM D4052 - Standard Test Method for Density and Relative Density of Liquids by Digital Density Meter (Método de prueba estándar para densidad y densidad relativa de líquidos mediante densímetro digital)
ASTM D5002 - Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer (Método de prueba estándar para densidad y densidad relativa de aceites crudos mediante analizador de densidad digital)
ASTM D1250 - Guía estándar para tablas de medición de petróleo
ASTM D5931 - Densidad y densidad relativa de concentrados de refrigerante para motores y refrigerantes acuosos para motores mediante densímetro digital
DIN 51 757 - Ensayo de aceites minerales y materiales relacionados; determinación de la densidad
ISO 12185 - Productos derivados del petróleo - Determinación de la densidad - Método del densímetro digital
Más información sobre la línea de densímetros de Rudolph Research
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