Come visit our stand to view any of the following products!


Acoustic sensor transmitters

The Thelma Biotel transmitters are energy efficient and versatile platforms developed for a wide range of studies on aquatic species and submerged equipment. The transmitters are highly customizable in both hardware and software.

The sensors available are depth, temperature, acceleration (activity), inclination (tilt angle), mortality, conductivity in fresh water and salinity in salt or brackish water. All sensor combinations are available down to the smallest size, except for the conductivity and salinity products which have a minimum size of 9 mm in diameter. The transmitters can be programmed to utilize any carrying frequency between 63-77 kHz, and at any transmitting interval. Our sensor transmitters also support measurements directly on submerged moving structures or other physical measurements where wireless data access is important. 

Aquacultural research and management are applications where our sensor transmitters help make data available which is otherwise impossible to obtain, monitoring welfare and behavioral responses of cultured fish by physiological measurements on individuals.

To read more about our sensor transmitter possibilities, click here.


XP56 – Acoustic sensor transmitter for continuous monitoring of subsea installations over extended amounts of time

The sensor transmitter has a large and robust casing equipped with batteries to exceed an operational time of 10 years. The XP56 can be fitted with multiple sensors, including depth (pressure), temperature, and tilt.


  • Wireless sensor system
  • Flexible and custom programming
  • Robust housing
  • Long transmit range


  • Long-term monitoring of subsea installations
  • 3D positioning of sea cages
  • Anchor line monitoring
  • Envionmental monitoring

The sensor transmitter is intended for monitoring subsea installations, sea cages, and anchoring down to 500 meters.

All sensor parameters are programmable and will be decided according to the project requirements. These include sensor range, sensor resolution, transmit interval, frequency, transmit protocol, and the order of transmitted sensor values. 

In projects where one specific sensor type needs to be emphasized, the order of the transmits can be programmed to focus specifically on one or more parameters. By using a dual protocol, two parameters can be transmitted simultaneously. Dual protocols are an advantage in 3D positioning, where the depth value is required to get an accurate position.

In addition to having highly flexible programming options as a standard, Thelma Biotel also offers custom programming to optimize the data output for any project. The acoustic transmitters can calculate averages over time, filter out the minimum and maximum values, orbe programmed to measure and process small amounts of data consecutively.


Link LoRa – Real-time tracking and monitoring

The Link LoRa system offers real-time tracking in the comfort of your own chosen location.

Real-time visualization of detections, sensor data graphing and download of datasets is available as the data is ticking in. Several nodes of Live hydrophones and Link LoRa with GPS/radio antennas can be deployed in an area. The nodes send radio signals to one single gateway up to 3-5 km away. One SIM card phone subscription or internet access point is enough to access a network of LoRa nodes. The system offers great flexibility for direct documentation and stakeholder involvement.

To read more about the Link LoRa system, click here.

How does the Link LoRa system work?

How does the transmitter detections translate into real-time tracking?

As shown in the diagram below, the deployed transmitters’ acoustic signals are picked up by the Live hydrophone. Data from the Live is sent through cable to the Link main unit where they are sent to the gateway as radio signals from the LoRa antenna module. The gateway is connected to either WiFi/LAN or phone SIM. The data is then transferred to an online MQTT broker service where you can access your data directly, or we can pull it and visualize it on the website interface we set up for you. The gateway is the only system component needing mains power access and internet or phone coverage. One gateway can be used for over 20 Link LoRa nodes.


Live – digital multi-frequency acoustic receiver


  • Advanced digital signal processing
  • 15 channels, 63-77kHz frequency range
  • Designed for very low power consumption
  • Simultaneous use of up to 3 frequency channels
  • Millisecond timestamping
  • Real-time data output over RS-485
  • Transmit ability
  • Transponder ranging ability

The Live is a digital multi-frequency acoustic receiver that spans 63kHz through 77kHz with precise millisecond timestamping allowing for fine scale positioning. It immediately relays acoustic detections to the surface using the robust and versatile industrial standard RS-485. The compact and rugged form factor of the receiver allows for installation in rough environments where space may be limited while also keeping the sensitive acoustic element protected. Live is designed with a strong emphasis on low power consumption such that it may operate directly on your field laptop or for months and years on small battery packs.

To read more about the Live transciever, click here.