Emerson Process Management 5300 manual Transition Zones, Dielectric, Flexible Single Lead Coaxial

Rosemount 5300 Series

Reference Manual

00809-0100-4530, Rev BA July 2009

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 2-7illustrates how the measuring range is related to the Transition Zones:

Figure 2-7. Transition Zones

Upper Reference Point

Upper Transition Zone

20mA

%	Maximum
-100	Recommended
	Measuring Range
Range 0

4mA

Lower Transition Zone

Table 2-2. Transition Zones for different probe types and dielectric constants

	Dielectric	Rigid Single Lead	Flexible Single Lead	Coaxial	Rigid Twin Lead	Flexible Twin Lead
	Constant
Upper(1)	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)
Transition
	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)
Zone
Lower(2)	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)
Transition	2	2.8 in. (7 cm)(5)	2 in. (5 cm) - long weight(4)	2 in. (5 cm)	4 in. (10 cm)	5.5 in. (14 cm)(4)
Zone			3.2 in. (8 cm) - short weight(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.

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.

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