ZFG D plus
State-of-the-art measurement electronics. Control the measurement process with a mobile device, evaluate and supplement measurement data and create reports. > Flyer
ZFG 3.1
With a small handheld device for displaying the measured values. Maximum mobility, simply slung over the shoulder. > Flyer
ZFG 3000
With compact measuring electronics in a robust case, including a printer, for display the measured values. Can also be operated with the lid closed. > Flyer
Calibration centers and services worldwide : Quality made in Germany
The Benchmark in Dynamic Plate Load Testing.
Over 70,000 ZORN devices are in use worldwide – many of them performing flawlessly for decades. That’s what real quality looks like.
With more than 150 years of precision-engineering expertise, ZORN INSTRUMENTS Germany delivers measurement technology you can trust: exceptional accuracy, uncompromising durability, and industry-leading service supported by a global network of calibration centers. We know our devices inside out – and we know exactly what your construction site demands.
If safety, precision, and long-term reliability matter in your dynamic plate load testing, choose the Light Weight Deflectometer from ZORN.
Get your no-obligation consultation today and discover how simple reliable compaction testing can be – with ZORN, the service leader.
Correct use of the Light Weight Deflectometer – video tutorial
Transport LWD safely and easily
...whether individually in the boot or neatly stowed away in the sturdy ACC transport case. What are the advantages of the magnetic base or the sack truck.
LWD assembly in just a few minutes
Here we show you how to safely install the LWD, connect the electronics correctly and benefit from the advantages of the LWD electronics 3000 and 3.1.
LWD measurement explained step by step
We demonstrate all steps required for correct measurement with the LWD: proper handling, acoustic control, carrying method and measurement quality on site.
Compare our top Light Weight Deflectometers
Why choose a ZFG D plus?
1. Wireless freedom
- Bluetooth connection to smartphone or tablet (Android & iOS).
- No annoying cables – greater freedom of movement and comfort on the construction site.
2. Easy to use
- Take measurements directly with a mobile device.
- Voice-guided measurement process.
- Create complete test reports on site (with the special D plus app or the ZORN FG-WebApp with even more options).
- Email reports quickly and easily.
3. Comprehensive documentation
- GPS coordinates of the measurement are recorded automatically.
- Air temperature at the test point with frost warning.
- Photos, soil and weather information as well as specific project details can be added to the test report.
4. Maximum efficiency
- Complete and simple data processing possible on site.
- Direct exchange of results with site management, colleagues or clients.
- Free app with ongoing updates included.
5. Future-proof solution
State-of-the-art technology combined with proven ZORN quality.
Internationally applicable thanks to multilingual app.
Robust, ultra-lightweight design for tough everyday use on construction sites.
More Details you find here.
Tablet, printer, magnetic base and other accessories are also available. Just ask your dealer or have look here.
Why choose a ZFG 3.1?
1. Handy and comfortable
Compact, ergonomic design of the measuring electronics in a robust plastic housing.
Durable full-leather case provides reliable protection against dust and splashing water.
2. Easy to use
Menu navigation easy to understand, even for non-experienced users.
Backlit, graphics-capable display with curve display.
Acoustic feedback while measurement.
Automatic calculation of settlement (s), s/v value, and deformation modulus Evd.
Option to enter text directly on the device for additional information.
3. Powerful equipment
Powerful WLAN module for wireless data transfer directly to smartphones, tablets, etc.
Precise positioning of measuring points with improved GPS/GNSS receiver.
Automatic storage on SD card with maximum storage capacity.
4. Connected & flexible
Free web app (multilingual) for secure reporting, report generation and emailing.
Fast data transfer via Wi-Fi - independent of smartphone/tablet.
Especially for users who prefer classic, standalone, compact measurement electronics.
More Details you find here.
Printers, magnetic base, carrying cases and other accessories are also available. Just ask your dealer or have look here.
Why choose a ZFG 3000?
1. Handy and robust
- Compact measuring electronics in a robust case with a practical option for operating the electronics from the outside with the lid closed.
- Dust and water-resistant, can also be used in harsh construction site conditions.
2. Easy to use
Menu navigation easy to understand, even for untrained users.
Backlit, graphics-capable display with curve display.
Acoustic feedback while measurement.
Automatic calculation of settlement (s), s/v value, and deformation modulus Evd.
Option to enter text directly on the device for additional information.
3. Powerful equipment
- Wi-Fi module for wireless data transfer to smartphones, tablets or PCs.
- GPS receiver for precise positioning of measurement points.
- Extremely powerful battery for long operating times on the construction site.
- Thermal printer for on-site printing.
4. Connected and flexible
Free ZORN FG-WebApp (multilingual) for secure evaluation, report generation and emailing.
Fast data transfer via Wi-Fi - independent of smartphone or tablet.
Ideal for users who prefer classic, standalone measurement electronics with an integrated printer.
More Details you find here.
Magnetic base, carrying case and other accessories are also available. Just ask your dealer or have look here.
Why choose a ZORN Mini?
1. For particularly narrow trenches
Smaller, oval load plate for testing in particularly narrow trenches from a width of just 120 mm.
Typical applications include trenches for broadband expansion/fibre optic cable laying.
2. Handy and comfortable
Compact, ergonomic design of the measuring electronics in a robust plastic housing.
Durable full-leather case provides reliable protection against dust and splashing water.
3. Easy to use
Menu navigation easy to understand, even for non-experienced users.
Backlit, graphics-capable display with curve display.
Acoustic feedback while measurement.
Automatic calculation of settlement (s), s/v value, and deformation modulus Evd.
Option to enter text directly on the device for additional information.
4. Powerful equipment
Powerful WLAN module for wireless data transfer directly to smartphones, tablets, etc.
Precise positioning of measuring points with improved GPS/GNSS receiver.
Automatic storage on SD card with maximum storage capacity.
5. Connected & flexible
Free web app (multilingual) for secure reporting, report generation and emailing.
Fast data transfer via Wi-Fi - independent of smartphone/tablet.
Especially for users who prefer classic, standalone, compact measurement electronics.
More Details you find here.
Carrying case and other accessories are also available. Just ask your dealer or have look here.
A Light Weight Deflectometer: The original ZFG (LWD) for precise soil testing!
The ZORN Light Weight Deflectometer (ZFG) is the practical solution for fast and reliable compaction testing in earthworks, road construction, civil engineering, sewer and pipeline construction, landscaping and bridge construction. In less than two minutes, you can use the dynamic plate load test according to different standards (see below) to determine the deformation modulus Evd and thus the bearing capacity and compaction quality of the soil – without the need for expensive load vehicles. This proven method provides construction companies, engineers and authorities with reliable results directly on site.
Thanks to its modular design, modern electronics (three to choose from) and state-of-the-art GPS/GNSS and Wi-Fi or Bluetooth equipment, measurement is particularly easy. The ZORN FG-WebApp, which is free for ZORN customers, enables precise and convenient documentation.
Very easy to use: even users with no prior knowledge can take reliable measurements with the Light Weight Deflectometer.
International standardisation of the Light Weight Deflectometer with ZORN
- Australia: Test Method Q258A Dynamic Modulus of Deformation Light Falling Weight Device Accelerometer Type
- Austria: RVS 08.03.04, Verdichtungsnachweis mittels dynamischen Lastplattenversuches
- Belgium: Standaardbestek 250 versie 5.0 (2024)
- Russia: N° 52068-12, Свидетельство об утверждении типа - State Register for approved measuring instruments
- Spain: UNE 103807-2:2021, Ensayo de carga vertical de suelos mediante placa dinámica. Parte 2: Placa rígida, diámetro 2r=300 mm, Método 2.
- Switzerland: VSS 70 313 (2025)
- Ukraine: DSTU B W.2.3-42:2016
- United Kingdom: BS 1924-2 (2025)
- USA: ASTM E2835-21, Standard Test Method for Measuring Deflections Using a Portable Impulse Plate Load Test Device
Video
Light Weight Deflectometer
Best Light Weight Deflectometer!? Additional advantages of all ZORN ZFG models:
- Tried-and-tested mechanics meet a flexible, selectable control module (see above) - individually expandable with accessories.
- Robust, surface-finished mechanics - ideal for harsh construction site conditions.
- Testing in confined spaces (e.g., bridge underpasses, pipe trenches)
- Can be used without a load vehicle or other aids
- Ergonomic triangular grab handle made from a single piece – does not roll away during transportation, no weld seams, lifetime warranty.
- Modular design: standard base plate with adapter pin for 150 mm plate or dynamic CBR test (laboratory and field)
- Calibration reminder plus unique self-test for maximum functional reliability
- Preload shocks, can be deactivated
- Integrated plausibility check
- Very short test duration of two minutes with very easy handling
- Professional instruction on site possible
- Application aids: videos, training courses, operating instructions and much more
All mechanical components of our testing and measurement technology are manufactured entirely in our factory in Germany. Components and accessories are sourced from first-class suppliers. This independence enables us to respond quickly to repairs and maintenance requests - even for models that have been in use for decades.
You can find the most important details about ZFG in our flyer.
...by the way.
High-precision test technology Made in Germany
Trusted by users in over 100 countries, ZORN INSTRUMENTS delivers innovative, reliable testing solutions.
For more than 70 years, we have developed and produced high-precision tools for quality testing – from fast on-site checks in road construction to classic laboratory material tests. With our mix of engineering expertise, craftsmanship, and close customer support, we provide solutions that meet the ever-changing demands of quality assurance. You can get an idea of our products in our digital showroom.
Ever heard about the Asphalt Tester?
No? Have a look.
Do you know the ZORN Pressure Filtration LAB!
Find out more.
FAQs | Development and History of the Light Weight Deflectometer
What role did ZORN INSTRUMENTS Germany play in the development of the Light Weight Deflectometer (LWD)?
An original is not created by making claims.
The Light Weight Deflectometer was not developed in 2009, when one of our competitors entered the market.
As early as 1977, extensive model calculations and parameter studies were carried out under the direction of Prof. Wolfgang Weingart. These were published in scientific form and played a significant role in the subsequent development of the test method.
Since the early 1990s, ZORN INSTRUMENTS has been part of this development. Since 1991, we have been manufacturing Light Weight Deflectometers as the first supplier in the field. Not as a marketing idea, but as part of the technical implementation: design, mechanics, manufacturing and continuous development based on the work of Prof. Weingart.
Precisely manufactured on our own CNC machines - then, and to this day. From theory to the construction site!
From the very beginning, we were also involved in the technical implementation and introduction of the Light Weight Deflectometer into the relevant German and some other national technical testing specification. Our contribution was not limited to the instrument itself; we also played a role in establishing the method for practical use in the field.
That is why our position is clear: An original is not created by making claims. An original is built through development work, experience and a verifiable history.
Anyone who does the math will quickly see the point: when others entered the market years later, that does not suddenly rewrite the history that came before.
And this is where the real difference lies: We do not simply sell large quantities of instruments. We support our customers for years. With technical expertise, accessible service, reliable calibration and genuine support when it matters.
Because a measuring instrument is only as good as the partner behind it.
For decades, we have stood…
for substance over noise.
for documented evidence over claims.
and for technology that not only works - but is supported.
What differentiates the Light Weight Deflectometers (LWDs) on the market?
Where can I buy the ORIGINAL Light Weight Deflectometer?
From us. Because if you do the math, the answer is clear.
Transparency starts with looking at publicly available company registers and historical company data. Platforms such as North Data or official commercial registers make it possible to objectively trace company histories, founding dates, developments and corporate relationships.
Especially in the field of technical measuring systems, this quickly reveals who was actually developing and manufacturing long before other suppliers entered the market and who came later.
“Original” is therefore less a matter of marketing claims and more a question of documented history.
One particularly important piece of evidence is our intellectual property right: as early as 1993, our Light Weight Deflectometer was registered as a utility model with the German Patent and Trade Mark Office (DPMA).
In other words: the history speaks for itself.
The original developer is the one who keeps developing the technology. That experience is what enables us to deliver a product that is continuously refined, highly reliable and built to perform.
Is ZORN INSTRUMENTS well known in the industry?
Yes - and has been from the very beginning. For many customers, this is an important factor when choosing a Light Weight Deflectometer.
When investing in equipment for the construction industry, customers want to know: Does the manufacturer have practical experience? Are the instruments well established in the market? Do other companies already trust this technology?
ZORN INSTRUMENTS LWDs have been used for decades on civil engineering and road construction projects worldwide, by both smaller construction companies and major infrastructure projects.
With more than 17,000 Light Weight Deflectometers delivered, our systems are now among the established solutions for dynamic soil compaction testing.
Many of our customers have been with us for many years - from their initial LWD purchase through regular maintenance and calibration.
For us, being well known is therefore not an end in itself. It is the result of:
- reliable measuring technology
- personal, accessible support
- and solutions that prove themselves in everyday construction work.
