Emerson Rosemount 3308 Series Reference Manual page 143

Reference Manual
00809-0100-4308
Table A-1: Maximum Recommended Viscosity and Contamination/Build-up
Probe type
Single lead
Twin lead
Coaxial
(1) Consult your local Emerson representative in the case of agitation/turbulence and high viscous
products.
A.1.4 Measuring range
Table A-2: Measuring Range and Minimum Dielectric Constant
Probe type
Flexible single lead
Rigid single lead probe (0.3-in./8 mm)
Rigid single lead probe (0.5-in./13 mm)
Segmented rigid single lead
Flexible twin lead
Coaxial
(1) Minimum Dielectric Constant may be lower than 2.0 if one or more of the following conditions apply:
• Probe is installed in stilling well or chamber.
• Maximum measuring range is not utilized.
• Noise Threshold is manually adjusted to a lower level.
Interface measuring range
The maximum allowable upper product thickness/measuring range is primarily
determined by the dielectric constants of the two liquids.
Typical applications include interfaces between oil/oil-like and water/water-like liquids,
with a low (<3) dielectric constant for the upper product and a high (>20) dielectric
constant for the lower product. For such applications, the maximum measuring range is
limited by the length of the coaxial and rigid single lead probes.
For flexible probes, the maximum measuring range is reduced by the maximum upper
product thickness, according to the diagram below. However, characteristics may vary
between the different applications.
Reference Manual
Maximum viscosity
(1)
8000 cP
1500 cP
500 cP
Maximum measuring range
55.8 ft. (17 m)
9.8 ft. (3 m)
19.7 ft. (6 m)
32.8 ft. (10 m)
55.8 ft. (17 m)
19.7 ft. (6 m)
Specifications and reference data
February 2020
Contamination/build-up
Build-up allowed
Thin build-up allowed, but no
bridging
Not recommended
Minimum dielectric constant
2.0, when distance < 32.8 ft. (10 m)
10, when distance > 32.8 ft. (10 m)
2.0
2.0
2.0
2.0, when distance < 32.8 ft. (10 m)
10, when distance > 32.8 ft. (10 m)
2.0
(1)
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