Troubleshooting guide

110
Reference Manual
00809-0100-4308, Rev BA
Appendix A: Reference Data
December 2014
Reference Data
A.2.4 Maximum measuring range and minimum dielectric
constant
Table A-3. Measuring Range and Minimum Dielectric Constant
A.2.5 Interface measuring range
The maximum allowable upper product thickness/measuring range is primarily determined by
the dielectric constants of the two liquids.
Target 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.
Figure A-7. Maximum Upper Product Thickness for Flexible Probes
Flexible single lead Rigid single lead Flexible twin lead Coaxial
Maximum measuring range 55.8 ft (17 m)
9.8 ft (3 m) for 8 mm
probes (code 4A)
19.7 ft (6 m) for 13
mm probes (code 4B)
55.8 ft (17 m) 19.7 ft (6 m)
Minimum dielectric constant
(1)(2)
(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.
(2) For temperatures above 140 °F (60 °C) manual adjustment of noise threshold may be required for products with low dielectric constant at or close to maximum
measuring range.
2.0 up to 32.8 ft (10 m)
10 up to 55.8 ft (17 m)
2.0
2.0 up to 32.8 ft (10 m)
10 up to 55.8 ft (17 m)
2.0
1
0
6.6 (2)
13.1 (4)
19.7 (6)
26.2 (8)
32.8 (10)
39.4 (12)
243
567
8910
11
80
80
40
20
10
10
Upper product dielectric constant
Maximum upper product thickness, ft (m)
Lower product
dielectric constant
Example: With an upper
product dielectric constant
of 2, and a lower product
dielectric constant of 20, the
maximum upper product
thickness is 25.3 ft (7.7 m).
25.3 ft (7.7 m)
DC 2
DC 20