API MPMS 9.4 pdf free download

API MPMS 9.4 pdf free download.Manual of Petroleum Measurement Standards Chapter 9.4—Continuous Density Measurement Under Dynamic (Flowing) Conditions.
5.3 Operation General 5.3.1 Personnel shall be aware of the specific hazards involved in continuous density measurement. Personal Protective Equipment (PPE) 5.3.2 Appropriate PPE should be worn at all times. Pycnometers 5.3.3 Filling, weighing, and emptying of pycnometers should be accomplished with minimal time delay, to limit any rise in temperature that might result in vessel rupture. The pycnometer shall be stored and transported in a clean and empty condition when not in use. Pressure Hydrometers 5.3.4 Exercise care when using these devices; adhere to all safety requirements as identified in the appropriate standards. Fluids 5.3.5 Ensure personnel are familiar with the fluid’s properties and hazards. Make available current safety hazard sheets documenting the fluid properties and required safety measures (i.e. safety data sheets or SDS).6 Density Determination Methods There are many ways to determine density. Density can be measured directly or calculated from composition or other fluid properties. Density can be measured directly on-line or measured off-line via a representative sample. On-line density measurement can be accomplished with a device located in the main flowing stream or located in a slipstream representative of the main stream.This standard addresses density measured continuously on-line, as shown in the shaded flowchart boxes in Figure 1 . “Continuous,” as defined in this standard (see 4.1 .1 2), is at least once per second on a recurring basis. Off-line and calculated density measurements may be used, where appropriate, as a means of verifying or calibrating an on-line density meter in-situ (see 1 1 .4 for details). The two primary dimensions to consider in selecting a density measurement method are the variability and predictability of the fluid density and the impact of density uncertainty on the final value in question, such as product value, quantity, quality, or other measure.7.2 Vibrating Element (Natural Resonance) If a fluid is contained by, or is part of, a body that is maintained in resonance at its natural frequency, the frequency of resonance, which is dependent on the total mass of the system, will change as the fluid density changes. The vibrating element may be in the form of a tube or tubes, cylinder, tuning fork, or flat plate. The vibrating-tube arrangement is mainly used for liquid density measurement since it provides a very clean flow path and is least affected by liquid viscosity. The application of vibrating-element instruments can make them sensitive to mounting position or vibration impacting the element or its supporting structure. Users should refer to manufacturers’ recommendations for the preferred mounting arrangement. The frequency output signals from these instruments make them directly compatible with high-accuracy digital computation techniques.7.6 Continuous Weighing The continuous weighing technique is probably the most basic method and is carried out either by continuous sampling and weighing in tanks or by passing the product through a horizontal U-tube arrangement. The U-tube is normally pivoted near the inlet points, and the apparent mass of the tube in air is balanced against a counterweight or externally applied force. As the density of the fluid in the tube changes, it is necessary to alter the force to maintain the balance. This force is directly related to the density change and can be applied either electrically or pneumatically. In consequence, the instrument produces an electrical or pneumatic signal that represents the density.API MPMS 9.4 pdf download.