Endress+Hauser Proservo NMS81, Техническая информация

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Proservo NMS81
14 Hauser
Density
Since the density is the calculated result of two measurements, a displacer with higher volume will
usually yield the most accurate density measurement. In most cases we recommend our
50 mm (1.97 in) diameter displacer for density measurement.
For non-viscous applications (e.g. white oil, LPG/LNG), the 70 mm (2.76 in) displacer also works
very well.
Level and density
When an application calls for equal emphasis on measuring both level and density, the
50 mm (1.97 in) and the 70 mm (2.76 in) diameter displacers will give the best all-around
performance.
Custody transfer
The 50 mm (1.97 in) displacer or larger is the choice for requirements per NMi.
The 110 mm (4.33 in), conical 316L displacer is the choice for requirements per PTB.
Material compatibility
Displacers are available in three different standard materials. Material compatibility should be
confirmed to ensure safe operation and optimal NMS8x performance.
316L
Stainless steel is a highly versatile industrial material that provides good compatibility with a wide
range of chemicals, including most white and black oils.
Alloy C
This high-performance material is harder than 316L, and provides excellent resistance to many of
the harshest corrosive chemical applications.
PTFE
One of the most well-known and versatile polymer materials, this high-performance material has
one of the lowest friction coefficients. It provides excellent performance in viscous/sticky liquids, and
also has excellent chemical resistance to a wide range of corrosives.
Process connection size
The process connection defines the tank process entry, and may affect the displacer size. The
standard NMS8x process connections start at 3”/DN80 and fit most tank gauging applications.
Accordingly, most applications can be covered with one of the 50mm or 70mm displacer options.
Smaller diameter displacers are available when the process connection is smaller.
When the 110 mm (4.33 in) diameter custody transfer approval (PTB) displacer is selected, a
separate calibration and maintenance chamber is recommended between the NMS8x and tank
process connection.