Precision Non-Contact Ultrasonic Technology for Level and Flow Applications

The KOBOLD NUS-4 ultrasonic level transmitter delivers reliable, non-contact continuous measurement using advanced time-of-flight ultrasonic technology. The integrated evaluating electronics precisely calculate echo time from ultrasonic pulses traveling to the media surface and back, ensuring accurate measurements with exceptional reliability. The NUS-4 is also capable of volumetric flow measurements of open channels using pre-programmed flow calculation algorithms.

Core Technology Advantages:

5°-7° beam angle at -3 dB ensures focused measurement even with obstructions
Non-Contact operation eliminates sensor fouling and maintenance issues
Direct-mounted electronics provide compact, integrated solution
Temperature compensation maintains accuracy across varying conditions

Level Measurement Applications

Tank and Vessel Monitoring

The NUS-4 excels in continuous level measurement across diverse industrial applications where traditional contact-based sensors fail or require frequent maintenance. The NUS-4 offers the ability to choose from a variety of pre-programmed tank shapes for easy set-up of volume measurement.

Storage and Process Tank Level Monitoring

Chemical storage tanks
Water treatment storage systems
Petroleum and fuel storage
Liquid storage silos
Food and beverage holding tanks
Clarifiers and settling tanks
Buffer tanks and surge vessels
Clean-in-place (CIP) system tanks

Challenging Media Applications

Corrosive acids and aggressive chemicals
Viscous or adherent materials
Contaminated or dirty liquids
Hygienic applications

ULtrasonic Level Measurement Advantages Over Other Technology Types

Versus Pressure Transmitters

No impulse line clogging from debris
No wetted parts to corrode, degrade, or require cleaning

Versus Float Level Switches

Continuous measurement vs. point-level detection
No mechanical wear components or moving parts
Suitable for corrosive applications

Versus Capacitive Level Sensors

Unaffected by changing media dielectric constant
No calibration drift from coating or buildup
Eliminates rod cleaning and maintenance

Versus Guided Wave Radar

More cost-effective for simple level applications
No probe in contact with the media
Simpler installation with no insertion length calculations

Level Measurement Installation Best Practices for Ultrasonic Level Sensors

Optimal Sensor Positioning

Mount at highest expected level considering dead zone limitations
Position away from fill pipes and agitators to avoid turbulence interference
Ensure clear level line-of-sight to liquid surface
Avoid mounting near vessel walls or internal structures

Performance Optimization

Configurable damping for surface turbulence or high vapor conditions
Ability to filter out fixed object in the measurement path
Compensation for dome topped tanks
Calibrate with actual media for maximum accuracy
Programable alarm levels for process control integration

Level Measurement Technical Specifications

Measurement Range: Up to 82ft (model dependent)
Accuracy: ±0.2% of reading +0.05% of full-scale
Resolution: up to approximately 3/64” (range dependent)
Operating Temperature: -22°F to 194°F
Process Pressure: Up to 43 psi gauge
Beam Angle: 5°-7° at -3 dB
Delay Time: 10, 30, 60 seconds (programmable)

Open Channel Flow Measurement Applications

Non-Contact Flow Monitoring in Open Channels

Transform the NUS-4 into a powerful open channel flow meter by combining precise level measurement with flow calculation algorithms. This approach provides accurate, continuous flow monitoring for typical open channel designs.

Primary Flow Measurement Applications

Municipal Water Systems

Raw water intake monitoring
Reservoir and storage flow measurement
Water treatment plant flow monitoring

Wastewater & Stormwater Management

Treatment plant influent/effluent flow
Collection system flow measurement
Stormwater runoff quantification
Sewer overflow monitoring

Industrial Process Flow

Cooling water system monitoring
Process water flow measurement
Wastewater discharge monitoring
Irrigation system flow control
Mining and aggregate wash water

Environmental Monitoring

Stream and river flow gauging
Groundwater monitoring systems
Agricultural drainage measurement
Environmental compliance monitoring
Flood warning system integration

Open Channel Flow Measurement Principles

The NUS-4 measures water level upstream of calibrated flow restrictions that create predictable level-to-flow relationships pre-programmed applications such as:

Weir Applications

V-notch weirs
Rectangular weirs
Trapezoidal weirs
Circular weirs
Bottom step weirs

Flume Applications

Parshall flumes
Palmer-Bowlus flumes
Khafagi-Venturi Flumes

Ultrasonic Level Sensor Flow Measurement Advantages over Radar Level Transmitters

More cost-effective solution
No issues from electromagnetic interference

Open Channel Flow Installation Guidelines for Ultrasonic Level Sensors

Sensor Positioning

Install as close as possible above the expected maximum water level, taking into consideration the dead zone limitations.
Install the device as defined by the characteristics of the metering channel
Mount to avoid spray, foam, or vapor interference
Ensure stable mounting immune to vibration

Channel Requirements

Follow open channel best design practices
Uniform cross-section upstream of measurement point
Adequate downstream conditions to maintain flow regime
Proper primary element sizing for expected flow range

Flow Calculation Setup

Configure channel geometry parameters
Program weir/flume coefficients
Calibrate with known flow rates when possible

Flow Measurement Technical Performance

Flow Accuracy: ±2-5% of reading (depending on primary element)
Turndown Ratio: Up to 10:1 typical
Minimum Detectable Flow: 1.5 GPM (application dependent)
Maximum Flow Capacity: Limited by channel design
Data Logging: Optional with external flow computer
Communication: 4-20mA, HART

Universal Featured and Specifications

Optional Programming Unit

Pluggable LCD display module
On-site configuration and calibration
Real-time measurement display
Alarm setpoint programming
Diagnostic information access

Output Configurations

Analog: 4-20 mA
Digital: HART protocol communication
Relay: Programmable differential level control, counter pulse, or echo loss alarm functions.
Display: Optional local LCD indication