Ultrasonic Level Transmitter Selection Guide: Range, Installation and Applications
An ultrasonic level transmitter can have the correct measuring range and still give unreliable readings if it is installed at the wrong location.
This happens more often than buyers expect.
A transmitter may be mounted too close to the tank wall, directly above the filling point, or so close to the maximum liquid level that the liquid enters the sensor's blind zone. The result is usually blamed on the instrument, even though the real issue is installation.
That is why selecting an Ultrasonic Level Transmitter is not only about asking, "Is it 5 metre, 10 metre or 15 metre range?"
You also need to check the tank geometry, maximum level, output signal, mounting arrangement, environmental conditions and the distance available between the sensor and the liquid surface.
The Radical TechArt ultrasonic level transmitter covered in the supplied PDF is available in 0 to 5 m, 0 to 10 m and 0 to 15 m measuring ranges, with ±0.5% FS stated accuracy, 24 VDC supply and standard 4 to 20 mA output. RS485, flange mounting and PTFE probe options are listed as custom configurations.
What is an Ultrasonic Level Transmitter?
An ultrasonic level transmitter is used for continuous level measurement without requiring the sensing probe to remain immersed in the liquid.
This makes it particularly useful for applications such as:
These applications are specifically shown in the supplied product PDF, including actual installation examples on page 3.
For a maintenance team, the attraction is simple: the sensor can measure from above the liquid rather than requiring a probe to continuously sit inside the process.
That can simplify installation in many water based applications.
How Does an Ultrasonic Level Transmitter Work?
The supplied PDF does not explain the sensing principle in detail, so the following is general ultrasonic measurement background.
An ultrasonic transmitter sends a high frequency sound pulse toward the liquid surface. The pulse reflects from the surface and returns to the sensor.
The instrument measures the travel time of that signal. Since the speed of sound is known, the transmitter can determine the distance between the sensor and the liquid surface.
From this distance, the system can calculate the liquid level.
In practical automation systems, that measured level can then be sent as an electrical signal to other equipment.
For the transmitter in the supplied PDF, the standard output is 4 to 20 mA, with RS485 available as a customized option.
This makes the transmitter suitable for applications where the measured level needs to be sent to a:
Final communication compatibility should always be checked against the actual PLC, controller or monitoring system being used.
Ultrasonic Level Transmitter Available Range and Specifications
This product is useful when continuous level measurement is required over short to moderately long distances, particularly in water related applications.
Technical points to note
| Parameter | Available specification |
|---|---|
| Product | Ultrasonic Level Transmitter |
| Accuracy | ±0.5% FS |
| Measuring range | 0 to 5 m / 0 to 10 m / 0 to 15 m |
| Working temperature | minus 20°C to plus 60°C |
| Blind zone | 0.35 m to 0.6 m |
| Power supply | 24 VDC |
| Standard output | 4 to 20 mA |
| Optional output | Customized RS485 |
| Installation | G2 thread |
| Optional installation | Customized flange |
| Probe material | ABS |
| Optional probe material | Customized PTFE |
These specifications come directly from the product parameter table on page 1 of the supplied PDF.
The Blind Zone Matters More Than Many Buyers Realize
The 0.35 m to 0.6 m blind zone is one of the most important specifications in this product.
A blind zone is the area immediately below the sensor where reliable level measurement cannot be expected.
For example, imagine your tank is almost completely full and the liquid surface reaches very close to the ultrasonic probe. If that surface enters the blind area, the transmitter may no longer provide the measurement you expect.
This is exactly why the installation diagram on page 2 states that the upper material level must not enter the measurement blind area.
Before ordering, do not only ask:
"What is my tank height?"
Also ask:
"How close will the maximum liquid level come to the sensor?"
That second question can determine whether the installation works correctly.
How to Choose the Right Measuring Range
The PDF offers three measuring ranges:
0 to 5 Metres
Suitable for relatively smaller tanks, sumps, storage vessels and similar level measurement points where the total measurement distance remains within 5 metres.
0 to 10 Metres
Better suited for deeper tanks, water storage systems and larger level measurement applications.
0 to 15 Metres
Useful where a longer measuring distance is required, including deeper water storage, reservoir or similar monitoring applications.
Do not automatically select 15 metres because it is the largest available range.
Choose the range according to actual installation distance, maximum and minimum level, blind zone and the surrounding geometry.
Installation Distance From the Wall
This is another useful detail in the supplied documentation.
The PDF gives the following reference distances between the measurement installation and the wall:
| Measuring Range | Referenced Wall Distance |
|---|---|
| 5 metres | 0.5 metre |
| 10 metres | 1 metre |
| 15 metres | 1.5 metres |
These distances are shown in the installation guidance on page 2.
Why does this matter?
An ultrasonic signal needs a reasonably clear measurement path. Installing the sensor in a poor location can cause unwanted reflections from surrounding structures.
In actual plant conditions, this means you should not simply find an empty threaded opening on the tank and install the transmitter there.
The mounting position needs to be selected deliberately.
Correct Installation of an Ultrasonic Level Transmitter
The installation diagram on page 2 of the PDF gives several practical instructions that are worth following carefully.
1. Keep the Liquid Below the Blind Area
The maximum material or liquid level should not enter the sensor's blind zone.
This should be checked during design, not after commissioning.
2. Avoid the Filling Point
The PDF specifically instructs that the feeding port should be avoided when measuring material level.
This is important because incoming liquid can disturb the measurement surface and create an unstable measurement condition.
A common field mistake is placing the ultrasonic transmitter directly above the inlet because that location is mechanically convenient.
Convenient mounting does not always mean correct mounting.
3. Mount the Sensor Properly
The installation illustrations show the transmitter mounted vertically above the measured surface.
Angled mounting is shown as incorrect.
The reason is practical: the sensor needs a suitable measurement path toward the target surface and back.
4. Do Not Mount Too Close to the Wall
The illustrations also warn against poor placement close to the vessel side.
Use the range and wall distance references as part of the installation assessment.
5. Protect Outdoor Installations
The PDF recommends long term rain protection when the transmitter is installed outdoors.
Even when an instrument has protected construction, a sensible canopy or installation arrangement can help reduce direct environmental exposure.
Construction Features Worth Noticing
The product information also highlights several construction details.
Transparent Upper Housing
The transparent shell is intended to make viewing easier while providing dust protection.
Protective Electrical Interface
The PDF describes an ABS electrical interface designed with resistance to impact, ageing and temperature conditions.
Internal Sealing
A sealing ring and internal shock protection arrangement are referenced to support firm installation and overall sealing.
Enclosed Probe
The probe is described as a fully enclosed integrated design intended to protect the internal circuit.
ABS and Optional PTFE Probe
ABS is the listed standard probe material, while PTFE is available as a customized option.
For applications involving media other than normal water, material compatibility should be confirmed before ordering rather than assuming the standard ABS version is suitable.
Common Applications
The PDF gives a clear idea of where this ultrasonic transmitter is intended to be used.
Water Storage Tanks
This is probably the most straightforward application.
The transmitter can continuously measure water level and provide a 4 to 20 mA signal to a panel, PLC or monitoring system.
This can support:
Actual control functions depend on the connected automation system.
Reservoir and River Level Monitoring
Page 3 shows a reservoir or river installation example.
This type of non contact measurement can be useful where direct sensor contact with water is undesirable or inconvenient.
Sewage Applications
The PDF also shows sewage disposal as an application.
For actual sewage installations, site conditions should be evaluated carefully because foam, turbulence, obstruction and mounting geometry can affect ultrasonic measurement performance.
The supplied PDF does not give specific performance limits for these conditions, so suitability should be confirmed for the exact application.
Wells
Well level measurement is included in the listed usage scenarios.
Before selecting the transmitter for a well, check the total measurement distance and available clear space around the ultrasonic measurement path.
Industrial Automation Water Storage Tanks
The product documentation specifically shows an industrial water storage application.
This is where the 4 to 20 mA output becomes particularly useful because the reading can be integrated into an industrial monitoring or automation system.
Common Mistakes to Avoid
| Common mistake | Better approach |
|---|---|
| Selecting only by tank height | Check range, blind zone and mounting height together |
| Mounting directly above the inlet | Keep the transmitter away from the filling point |
| Installing very close to the wall | Maintain suitable clearance based on installation requirements |
| Installing the sensor at an angle | Keep the measurement path correctly oriented toward the liquid |
| Ignoring the 0.35 to 0.6 m blind zone | Ensure maximum level remains outside the blind area |
| Assuming RS485 is standard | Standard output is 4 to 20 mA, RS485 is listed as customized |
| Assuming flange mounting is standard | G2 thread is standard, flange is listed as customized |
| Selecting ABS for every liquid | Confirm chemical compatibility, PTFE is listed as an optional customization |
| Ignoring outdoor exposure | Provide suitable rain protection for long term outdoor installation |
Do This, Not That
| Do This | Not This |
|---|---|
| Calculate maximum and minimum measurement distance | Choose range only from tank capacity |
| Check the blind zone before fixing mounting height | Mount the sensor directly above maximum liquid level |
| Keep the transmitter away from the inlet | Install wherever a spare nozzle is available |
| Confirm 4 to 20 mA or RS485 requirement | Assume both outputs are standard |
| Confirm G2 thread or customized flange requirement | Order before checking mechanical mounting |
| Check process media before selecting probe material | Assume ABS is suitable for every application |
Quick Selection Checklist
Before ordering an ultrasonic level transmitter, confirm:
- What liquid or medium is being measured?
- What is the total measurement distance?
- Is 5 m, 10 m or 15 m range required?
- What is the maximum liquid level?
- Will the maximum level remain outside the 0.35 to 0.6 m blind zone?
- Is sufficient clearance available from the vessel wall?
- Can the transmitter be installed away from the filling point?
- Do you need 4 to 20 mA or customized RS485?
- Is 24 VDC power available?
- Is G2 threaded installation suitable, or is a customized flange required?
- Is ABS suitable for the application, or should PTFE be considered?
- Will the transmitter be installed outdoors?
Specifications to Confirm Before Purchase
Before final selection, confirm:
The available PDF lists the principal product specifications, but it does not provide detailed information on IP rating, communication register structure, display programming, hazardous area certification or performance under foam and vapour conditions. These points should be confirmed separately if they are important to the application.
Why Buy an Ultrasonic Level Transmitter from Radical TechMart?
An ultrasonic transmitter should not be selected only by searching for a 5 metre or 10 metre level sensor.
The actual requirement includes the liquid, tank height, maximum level, mounting position, output, power supply and control system.
At Radical TechMart, the focus is to help industrial buyers select instrumentation according to the application rather than only matching a product name.
Support can include:
Final Thoughts
An Ultrasonic Level Transmitter is a practical choice for continuous level measurement in water tanks, reservoirs, wells and similar applications, especially where non contact measurement is preferred.
But correct installation is just as important as correct range selection.
A 15 metre transmitter installed too close to a wall or inside its blind zone can cause more trouble than a properly selected 5 metre transmitter installed in the right location.
Before purchasing, confirm the measuring distance, blind zone, mounting position, output signal and process conditions together.
That is what turns a level transmitter from simply another instrument into a reliable measurement point.
FAQs
1. What is an ultrasonic level transmitter used for?
It is used for continuous level measurement. The supplied product documentation lists water storage tanks, reservoirs, rivers, wells, sewage disposal and industrial water storage applications.
2. What measuring ranges are available?
The listed ranges are 0 to 5 metres, 0 to 10 metres and 0 to 15 metres.
3. What is the accuracy of this ultrasonic level transmitter?
The product PDF specifies an accuracy of ±0.5% FS.
4. What output does the transmitter provide?
The standard listed output is 4 to 20 mA. RS485 is available as a customized option.
5. What is the blind zone?
The listed blind zone is 0.35 m to 0.6 m. The maximum liquid level should remain outside this area.
6. Can an ultrasonic level transmitter connect to a PLC?
A 4 to 20 mA level signal can generally be connected to a compatible PLC analog input. Final wiring, scaling and electrical compatibility must be checked with the PLC specification.
7. Can the transmitter be flange mounted?
The PDF lists G2 thread as the standard installation method and customized flange installation as an option.
8. Can it be installed outdoors?
The product documentation recommends providing long term rain protection for outdoor installations.
