Emerson Process Management ROSEMOUNT 5300 - Manual (Page 24)

Reference Manual
00809-0100-4530, Rev BA
July 2009
Rosemount 5300 Series
2-10
Transition Zones The measuring range depends on probe type and product properties, and is
limited by the Upper and Lower Transition Zones. In these zones,
measurement accuracy may be reduced. The Upper Transition Zone is the
minimum measurement distance between the upper reference point and the
product surface. At the end of the probe, the measuring accuracy is reduced
in the Lower Transition Zone. The Transition Zones vary depending on
probe type and product.
Figure 2-7 illustrates how the measuring range is related to the Transition
Zones:
Figure 2-7. Transition Zones
NOTE!
Measurements in the Transition Zones may be non-linear, or have reduced
accuracy. It is recommended the 4-20 mA points be set between the
Transition Zones.
Table 2-2. Transition Zones for
different probe types and dielectric
constants
Dielectric
Constant Rigid Single Lead Flexible Single Lead Coaxial Rigid Twin Lead Flexible Twin Lead
Upper (1)
Transition
Zone
80 4.3 in. (11 cm) 4.3 in. (11 cm) 4.3 in. (11 cm) 4.3 in. (11 cm) 4.7 in. (12 cm)
2 6.3 in. (16 cm) 7.1 in. (18 cm) 4.3 in. (11 cm) 5.5 in. (14 cm) 5.5 in. (14 cm)
Lower (2)
Transition
Zone
80 2 in. (5 cm) 0 in. (0 cm) (4)(3) 0.4 in. (1 cm) 1.2 in. (3 cm) 2 in. (5 cm) (4)
2 2.8 in. (7 cm) (5)
2 in. (5 cm) - long weight (4)
3.2 in. (8 cm) - short weight (4)
2 in. (5 cm) 4 in. (10 cm) 5.5 in. (14 cm) (4)
(1) The distance from the upper reference point where measurements have reduced accuracy, see picture above.
(2) The distance from the lower reference point where measurements have reduced accuracy, see picture above.
(3) The measuring range for the PTFE covered Flexible Single Lead probe includes the weight. For low dielectric media, special configuration may be
required.
(4) Note that the weight length adds to non-measurable area and is not included in the table. See “Dimensional Drawings” on page A-9.
(5) If using a metal centering disc, the lower transition zone is up to 8 in. (20 cm). If using a PTFE centering disc, the lower transition zone is not affected.
4mA
20mA
Upper Transition Zone
Lower Transition Zone
Range 0
-100 %
Maximum
Recommended
Measuring Range
Upper Reference Point