The ISL LM1100 Ultrasonic Level Sensor is a flexible and configurable, battery operated, ultrasonic level sensor with an integrated LoRaWAN radio.

The ISL LM1100 Ultrasonic Level Sensor can be used to monitor a wide range of liquids, including fuel (oil & kerosene), water, waste oil and more.

With remote monitoring via LoRaWAN networks, this helps you ensure continued supply and optimise delivery or collections. The ISL LM1100 Ultrasonic Level Sensor includes low and high alarms for edge intelligence.

  • Liquid level monitoring

  • Suitable for a range of liquids, including fuel (oil & kerosene), water and waste oil
  • Ensure continued supply
  • Optimise delivery or collection logistics
  • Spot and continuous inventory management
  • 24/7 monitoring
  • Low and high level alarms
  • Easy to install
  • Up to 14 year battery life (depending on transmit interval)
  • Cost effective for large scale deployment
  • Up to 15km range


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Long Battery Life

Our sensors have been designed to have a battery life of up to 10 years, so you don't have to worry about changing them frequently.


Reduce Costs

Identify problems before damage occurs to stop waste, prevent costly site shutdowns and reduce your fuel consumption. 


A Proven Partner

At Invisible Systems, we've worked in IoT for over 17 years. Our solutions have a proven track record in supporting businesses. 

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Real-Time Online

Together with Real-time Online, the sensors enable constant monitoring, deliver pro-active alerts on threshold breaches and generate bespoke reports


Reduce Carbon Emissions

Our products have been proven to reduce carbon emissions by as much as 83% on some construction sites

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Easy to Install

Choosing wireless sensors and a cloud platform enables you to reduce your installation and maintenance costs.



Configurable high/low thresholds allow different transmit intervals when thresholds are crossed providing advanced edge intelligence to the network, and enable alarms to be generated by Realtime-Online™.


Data from every sensor in your network is reported back through Invisible Systems Big Data architecture either to our Monitoring and Analytics platform Realtime-Online™, or to a partner cloud platform via our API, ensuring that your data is visible, actionable and valuable to your organisation.


The ISL LM1100 is a LoRaWAN certified device and Invisible Systems are members of the LoRa alliance. It offers both ABP and OTAA activation options and is designed to work with all LoRaWAN gateways and network servers.




Frequency: EU868

Expected range (line of sight): Up to 15km

LoRaWAN: Supports LoRaWAN 1.0.2 compliant 125/250 kHz bands

Output power: Up to +14dBm (25mW)


Approvals: CE


Dimensions (mm): 109x109x126 ±1mm

Weight: 220g including battery

Enclosure colour: Grey Pantone 422C

Housing material: UV stabilized polypropylene (compatible with oil)

Material compatibility: Suitable for use in tanks for the storage of water, diesel fuel, kerosene, gas oil types A2,C1,C2 and D as defined by BS2869

Operating temperature: -20°C to +50°C

Recommended storage temperature: -20°C to +25°C

Humidity range: 15% - 95%

Altitude range: <2km above sea level

Environmental protection: IP67 (outdoors)

Battery type: 3.6V Li-SOCl₂ Size 2/3AA

Expected battery life: Typically 14 years from activation (based on one ultrasonic measurement every 15 minutes, one transmit every six hours, excellent LoRaWAN coverage (SF7), and normal distribu-tion over the operating temperature range cen-tred at +25°C)


Gauge type: Ultrasonic

Ultrasonic range: 12cm to 400cm

Ultrasonic signal diversion: 30°

Ultrasonic resolution: ±1cm

Accuracy: Typically ±2cm

Tank mounting options: Fits directly into female 2” BSP thread (adapter available to fit directly to 1 ¼”, 1 ½” or 2” BSP threads)

Gasket (included): Material NBR 78mm(Ø) x 2.5mm(H) ±0.5mm

Download Datasheet