1. USonic™ Series Continuous Ultrasonic Level Transmitter
AMETEK Drexelbrook
205 Keith Valley Road
Horsham, PA 19044
(215)

2. Continuous Ultrasonics
USonic™ 2-wire ultrasonic system for liquid measurements
Two-wire, HART® (HARTWin version 2.4 or later)
1 – 30 ft. (0.3 to 9.1 m) range
Level, Distance, Open Channel Flow, Volume

3. Basic Continuous Sonic Theory
A short sound burst or “ping” is generated by a transducer
The sound rebounds from the surface being measured and the return echo is detected by the transducer

4. Basic Continuous Sonic Theory
Distance = t/2 from the acoustic transmission / reception of the reflected signal at the speed of sound, ~1100 fps (~335 sea level
Level = Distance – Tank Height
USonic - frequency is a nominal 50KHz

5. Beam Pattern
Convention: Beam angle is defined as the angle at which the signal strength is 3dB down (50% power) of nominal
The strongest energy is emitted perpendicular to the transducer face
Lower energy is emitted at other angles

6. USonic™ Series – 10° Beam Angle
Acoustic Side Lobes
Half Beam (5°) Angle Spread:
1.05” / Ft (9 cm / m) from centerline.
30 ft. (9.1 m)

7. Distance vs. Beam Angle & Accuracy
Feet (meters)
Half Beam (5°) Spread Inches (cm)
+/- Accuracy
Inches (mm)
(3)
(27)
(5)
(4.5)
(40)
(7)
(6)
(53)
(9)
(7.6)
(67)
(11)
(9.1)
(80)
(14)
Accuracy specification: 0.15% or 0.2 inch (5mm), whichever is greater

8. Near Zone / Blocking Distance
12” (305 mm) Near Zone
Measurable Area
What is it?
Area below the transducer that is too close to measure
USonic: 12” (305 mm) from the transducer face
Causes
Level too high
Interfering tank structure
Recessed in nozzle (Use SmartGain™ to correct)

9. Near Zone / Blocking Distance
The required amount of time it takes a given transducer to become “quiet” to allow the reception of a return echo
The faster the transducer stops “ringing”, the shorter the near zone
Time = Distance
“Ring Down”

10. Near Zone / Blocking Distance
USonic
USonic can be recessed in a 2” (51 mm) or larger nozzle to allow measurement readings to the top of the vessel
12” (305 mm)
Dead Zone

11. ? Lost Echo What is it? Causes:
Lost echo occurs when the acoustic signal does not return to the transducer
Causes:
Excessive foam may absorb signal
Irregular target surface
Granular materials – angle of repose
Level is beyond measurement range
Coned / Dished tank bottom at low levels reflect signal away from transducer ?

12. USonic™ Features 2-wire loop powered, 4-20 mA, HART
30 ft. (9.1 m) measurement range
3 inch (76 mm) minimum span
12 inch (305 mm) Near Zone
Accuracy:
0.15% or 0.2 inch (5mm), whichever is greater
< 0.12 inch (3mm) Repeatability
< 0.12 inch (3mm) Resolution

13. USonic™ Features SmartGain™ Full Tank measurement Bench Configuration
Automatically ignores most internal vessel obstructions without user adjustments or recordings
Full Tank measurement
Recess sensor in a nozzle to read level to vessel top
Bench Configuration
Allows the system to be fully configured in the shop
Level and Open Channel Flow
Preconfigured flow tables for over 80 primary elements
21-pt. Strapping table for custom shapes and sizes
Housing options:
PBT (Valox UV stabilized) to NEMA 4X (IP 65)
XP, Cast Aluminum to NEMA 4X (IP 65)

14. USonic™ Specifications
Temperature:
-40° to 158°F (-40°C to 70°C)
Pressure:
-10 psig to 50 psig. (-0.7 to 3.4 bar)
Mounting Options: 2” NPT/BSP

15. USonic™ Features Configuration / User set up Configure via:
Menu driven, integral display with environmentally sealed keypad, UV protected display – all systems.
PC Software (HARTWin version 2.4 or later)
HART Handheld communicator (375 or later)
Display any or all of the following:
Level, Distance, Flow rate, Totalization, Temperature, Milliamp output.
Can auto scroll every 10 seconds.

16. USonic™ Features Supported Primary Flow elements:
Parshall, Rectangular Weirs (with and without end contractions), Trapezoidal Weirs & Flumes, V-Notch, Leopold-Lagco, Palmer-Bowlus, “H” Flume
Output signals in the following:
Level, Distance, Flow Rate, Volume

17. Models Available US-11 US-12 US-21 US-22
Valox housing with 2” NPT, indicating display
US-12
Valox housing with 2” BSP, indicating display
US-21
Valox housing with 2” NPT, indicating display
US-22
Valox housing with 2” BSP, indicating display

18. USonic™ Approval Schedule
FM Class I, Div. 1 (I.S.) & XP
CSA Class I, Div. 1 (I.S.) & XP
ATEX & CE Zone 0, Zone 1
(US-2X I.S. version only)
Pending

19. USonic™ – SmartGain™ SmartGain™ -
A Patented Algorithm embedded in the system that:
Automatically ignores obstructions
Eliminates Beam angle concerns
Allows sensor to be recessed into nozzles to eliminate the dead zone concerns inside of vessel
Beam
Angle

20. USonic™ – SmartGain™ feature
A 1” (25 mm) OD pipe can be as close as ½” (12 mm) from the centerline of the beam and ignored.
A 2” (50 mm) OD pipe can be as close as 1” (25 mm) from the centerline of the beam and ignored.
SmartGain is also a good choice for horizontal cylinders and spheres

21. SmartGain™ Comparison
Drexelbrook method:
Tank Mapping method:
Bulk mass of liquid reflects the greatest signal strength.
USonic automatically attenuates receiver gain (based on actual distance to level) to only accept strongest signal reflections.
Non-level reflections will not produce high enough signal strength to be identified & processed.
User must identify that non-level reflections are causing a problem – then enter a routine in the system to eliminate.
Unit receives all signals from both level and non-level reflections.
Unit adjusts Threshold level higher than reflections from non-level / base noise signals. Tank must be empty.

22. SmartGain™ Comparison
Drexelbrook benefit:
Tank Mapping problems:
A problem would usually occur before the user would run routine, because…
The vessel must be emptied or near empty
Agitators, or any moving objects, must be run during programming
User must identify actual level then subtract 1.6 ft. (0.5m)
User could misadjust, causing level reflection to also be ignored
No user routines or programs
Vessel doesn’t need to be empty
User can’t misadjust or null out level signal reflection
Future obstructions will be ignored without user intervention, or reprogramming

23. Configuration Menu Overview
Menu Function
Item
Description
1.0
Input Type
Level, Distance, Volume or Flow
Once a “type” is selected, menu will automatically jump to the section made.
2.0
Level
Enter all information for level readings
3.0
Distance
Enter all information for distance readings
4.0
Volume
Enter all information for volume readings

24. Configuration Menu Overview
Menu Function
Item
Description
5.0
Flow
Enter all information for flow readings, totalization
6.0
Strapping Tables
Enter Level vs. Vol. Data for up to 21 points
7.0
System Settings
Gain adjust., Rep. rate, TD, NZ / LE Faults, etc.

25. Configuration Menu Overview
Menu Function
Item
Description
8.0
Display Toggle
Select what is to be displayed; level, dist., vol., flow, totalizer, reset. Tot., output current, temp.
9.0
Calibration
(To adjust for speed of sound changes)
1-point cal. to known level.

26. USonic™ Applications in Water and Wastewater Treatment Plants
Chemical Slurries
Open Channel Flow
Lift Stations
Traveling Bar Screen
Sludge Storage
Water Filtration
Chemical Mixing
Water Wells
Sludge Digesters
Chemical Storage
Primary & Secondary Settling
Pump House