The Thelma Biotel Acoustic Depth Transmitters were originally developed for manual tracking of migrating Atlantic salmon smolt. The transmitter is capable of measuring 0 to 290 m water depth (0-30 bar). These transmitters have been used for tracking of migrating Atlantic salmon post-smolt down to 23 cm length. With the new and smaller depth tags available now, these tags can be used for even smaller fish. The depth sensors are extremely versatile and suitable for use in tracking of many different fish species, for deployment control of oceanographic instruments and infrastructures like the sinker tubes or cage weights in aquaculture facilites. The sensors are available in 7.3 mm, 9 mm, 13 mm and 16 mm sizes with different battery packs to suit the needs of different applications. Many different combinations of battery packs etc is possible, you are welcome to ask even though you don’t immediately find what you looking for in the product lists.
A larger housing with a threaded body is also available. This enables battery replacement and reprogramming in cases where the tags can be retreived. These tags are especially well suited for ultra long deployments of several years and for wireless measurements on equipment etc.
ID and Depth Transmitter
The transmitter is predominantly used as a coded transmitter (ID and depth), transmitting with fixed or random intervals. A coded transmitter’s battery life will be independent of the fish’s swimming depth.
Manual tracker transmitters
We have developed a special dual frequency manual tracker version of the depth tag where sensor data is sent on one frequency, like the 69 kHz. A second frequency is used to transmit a continous ping signal at a fixed ping rate. This way manual tracking can be done efficiently at one frequency with a fixed pulse rate. At the same time, data on depth and temperature (optional) is automatically logged on a second frequency as standard R-coded transmits. This solution gives you the option of using standalone loggers as well as multichannel receivers to back up and enhance data reception in your manual tracking set-up.