14
58-603 Pulsar
®
Model R86 Radar Transmitter
2.3.3.1 Maximum Distance
The chart below shows the maximum measuring range
(Distance) of each antenna based on fundamental condi-
tions of Dielectric, Distance and Turbulence. Distance is
measured from the Sensor Reference Point (bottom of NPT
thread, top of BSP thread or face of a flange).
2.3.3.2 Minimum Distance
If the liquid level is allowed onto the antenna, noise and
media build-up drastically decrease reliable measurement.
Liquid should not be allowed closer than two inches
(50 mm) from the bottom of the antenna or 12 inches
(300 mm) from the sensor reference point, whichever is
greater.
2.3.3.3 Problematic Applications; GWR Alternative
Some applications can be problematic for Non- Contact
Radar. For these, Guided Wave Radar is recommended:
• Extremely low dielectric media (
ε
r
<1.7)
• Stillwells, standpipes, bridles, cages and bypass columns.
• Very weak reflections from the liquid surface (particularly
during turbulence) can cause poor performance.
• Tanks heavily cluttered with false targets (mixers, pumps,
ladders, pipes, etc.)
• During times of very low liquid levels of low dielectric media,
the metal tank bottom may be detected which can deterio-
rate performance.
• Foam can either absorb or reflect the microwave energy
depending upon the depth, dielectric, density and wall
thickness of the bubbles. Due to typical variations in the
amount (depth) of foam, it is impossible to quantify per-
formance. It may be possible to receive most, some or none
of the transmitted energy.
• When measurement close to flange is critical
Extremely high liquid levels (Overflow) conditions when
liquid very near the antenna can cause erroneous read-
ings and measurement failure.
• Interface applications
Refer to Eclipse
®
Model 706 bulletin 57-106 for
additional information.
2" (50 mm)
12" (300 mm)
or
Sensor
Reference
Point
ANSI or DIN Welded Flange
R86 Maximum Recommended Measuring Range in feet (meters)
Turbulence None or Light
Turbulence Medium or Heavy
Dielectric >
1.7 – 3
3 – 10
10 – 100
1.7 – 3
3 – 10
10 – 100
A
n
te
n
n
a
T
y
p
e
1
1
⁄
2
" Horn
30 (9)
40 (12)
60 (18)
10 (3)
16 (5)
26 (8)
2" Horn
33 (10)
49 (15)
66 (20)
10 (3)
20 (6)
33 (10)
3" Horn
50 (15)
66 (20)
98 (30)
13 (4)
30 (9)
40 (12)
4" Horn
66 (20)
98 (30)
130 (40)
23 (7)
40 (12)
50 (15)
