Periodic Waterproofing Monitoring
SENSOR DDS® LMS

SENSOR DDS® LMS is a permanent offline monitoring system for waterproofing liners and geomembranes that enables precise leak detection and defect location during scheduled on-site measurements. Using a permanently installed sensor network and Electrical Leak Location – ELL principles, the system helps detect liner damage early, before it can develop into larger technical or environmental risks.

Global Leader Since

Leak Detection

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How Permanent Offline Waterproofing Liner Monitoring Works with SENSOR DDS® LMS

SENSOR DDS® LMS is a system for permanent offline monitoring of waterproofing liners and geomembranes, where a sensor network is permanently installed beneath or above the liner layer. This network creates a fixed basis for long-term waterproofing integrity control and makes it possible to regularly verify whether the liner has been damaged or whether a leak has occurred.

Measurement is carried out manually directly on site at agreed intervals, depending on the type of structure, operation and required level of control. Unlike one-time testing, this is not an inspection performed at a single moment only, but a solution that makes it possible to monitor the condition of the waterproofing liner over a longer period of time and detect changes early that may indicate liner damage.

An important advantage of the system is that the sensor layout is designed according to the specific project. The principle is simple – the denser the sensor network, the more precise the defect location. This is why waterproofing monitoring with SENSOR DDS® LMS is suitable for landfills, reservoirs, water tanks, building foundations, flat roofs and other structures where reliable leak tightness control is critical.

In a double-liner waterproofing system, this monitoring concept can be extended by installing a dedicated SENSOR detection layer – SENSOR DDS® LAM+ – which significantly increases the level of waterproofing integrity control. This layer is integrated into the build-up between the individual waterproofing liners and creates an active detection zone across the entire system area.

The system enables continuous 24/7 monitoring and, if a defect occurs, immediately identifies that a leak has occurred. Subsequent precise defect location is then carried out using the standard manual offline LMS system, which allows the exact failure point to be determined in the field. This combined approach provides rapid problem detection together with a reliable and proven method for precise defect location.

In practice, this system makes the most sense as part of a broader QA/QC process. After the liner has been installed, it can naturally be followed by leak testing on an exposed waterproofing liner, while after the layer has been covered, the next suitable step is leak testing on a covered geomembrane.

Application examples of SENSOR DDS® LMS permanent monitoring

SENSOR DDS® LMS is checked manually at regular intervals directly on site, making it a suitable solution for structures and operations where long-term confidence in the condition of the liner is required even after the waterproofing layer has been covered. A major advantage is that the system enables precise defect location, with the general rule that the denser the sensor network, the more accurately a leak can be identified. After each measurement, the current condition of the liner can also be evaluated and, under an agreed inspection regime, a confirmation of its integrity can be provided.

The most common applications of the SENSOR DDS® LMS system include:

Balconies
Mining ponds
Tunnels
Bridges

Benefits of SENSOR DDS® LMS Offline Permanent Monitoring

Permanent Offline Monitoring

SENSOR DDS® LMS enables long-term waterproofing liner and geomembrane integrity control through scheduled on-site measurements. It is a permanently installed offline system with a sensor network placed beneath or above the liner.

Efficient On-site Inspection

Measurement is carried out directly on site and provides an efficient, reliable way to verify liner condition at planned intervals without complex intervention into the structure.

No Cover Layer Limitation

The system is not limited by the type or thickness of the cover layer above the liner, because it verifies the integrity of the waterproofing layer itself. This is especially important where soil, gravel or other backfill is placed above the liner.

Clear Responsibility

If the measurement confirms that the monitored liner is intact and leak-free, the waterproofing layer can be excluded as the source of the issue, allowing other possible causes of leakage or contamination to be investigated.

SENSOR DDS® LMS enables waterproofing inspection at regular intervals

Showing Slide 1 of 8: SENSOR DDS LMS monitoring cabinet for regular geomembrane integrity checks

SENSOR DDS LMS sensor grid installed on a landfill liner for long-term monitoring

Field engineers operating the SENSOR DDS LMS portable monitoring system on site

SENSOR DDS LMS system installation on subgrade before geomembrane placement

Landfill geomembrane integrity monitoring during the early phase of waste placement

Portable SENSOR DDS LMS device used for on-site data collection and interpretation

SENSOR DDS LMS offline monitoring box with integrated sensor connections

Marked leak location identified by the SENSOR DDS LMS system using GPS

Frequently Asked Questions

What is SENSOR DDS® LMS?

SENSOR DDS® LMS is a permanent offline monitoring system for long-term integrity control of waterproofing liners and geomembranes. A sensor network – typically in a 5 x 5 m grid – is permanently installed beneath or above the liner and then allows the condition of the waterproofing system to be verified directly on site at regular intervals. Measurement is carried out manually by connecting the measuring device, according to the client’s requirements, usually every 6 to 12 months.

How does LMS detect damage before any medium starts leaking?

During measurement, it is not necessary to wait for an actual leak of water or another medium through the damaged area. The system works on the principle of electrical measurement, which makes it possible to detect and locate damage to the waterproofing layer earlier, before it develops into an operational or environmental problem.

When is the system installed?

SENSOR DDS® LMS is installed before the geomembrane or waterproofing liner is placed. The sensors become a permanent part of the structure, so after the liner has been covered, its integrity can still be checked during further construction or throughout the operation of the structure.

How often is measurement performed and how does the inspection itself take place?

LMS is an offline solution, so measurement is carried out directly on site using the portable SENSOR DDS® LMS device. The inspection interval is set according to the type of structure, operation and project requirements. After measurement, the current condition of the liner can be evaluated and, under an agreed inspection regime, a certificate of integrity can also be issued.

What is the accuracy of defect location?

Defect location accuracy depends mainly on the design of the sensor network. In general, the denser the sensor network, the more precisely the damaged area can be identified. If a leak is detected, the defect location can be determined, including GPS coordinates.

Does the type or thickness of the cover layer above the liner limit LMS?

No. SENSOR DDS® LMS is not limited by the type or thickness of the cover layer above the waterproofing layer, because it monitors the integrity of the liner itself. This is especially important for structures where backfill, protective layers or other operational material is placed above the liner.

When is SENSOR DDS® LMS more suitable, and when is SENSOR DDS® RMS the better choice?

SENSOR DDS® LMS is suitable where scheduled interval inspection directly on site is sufficient. If the project requires continuous 24/7 monitoring, online supervision, automatic alarms and immediate notifications, the more suitable solution is SENSOR DDS® RMS.

What is the service life of the system?

Permanently installed systems are designed for long-term operation. System components are BAM-certified by the German Federal Institute for Materials Research and Testing, which verifies their suitability for long-term technical use. In these applications, a minimum service life of 30 years is expected, which is especially important for landfills, reservoirs, lagoons and other structures where monitoring should match the service life of the waterproofing liner itself.

Keep your waterproofing under control even after the liner has been covered

SENSOR DDS® LMS is a solution for projects where one-time testing is not enough and a long-term overview of the waterproofing liner condition is required during operation. Regular offline measurements directly on site make it possible to detect damage early, locate leaks more precisely and reduce the risk of late intervention in an already completed structure.

Regular inspection – monitoring at intervals based on the structure type and operation
Precise defect location – faster decision-making for the next steps
Project-specific solution – system design based on the build-up, scope and required accuracy

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