The Thelma Biotel 9 mm acoustic transmitters are intended for use where size, output power, and long transmitting life are crucial. Manual tracking or automatic monitoring of larger salmon smolt migrating out of fjords is a potential area of use. The customer specifies pulse delay or coded ID, the type of encoding scheme, transmitting frequency, and minimum and maximum random delay for ID transmitters.

The 9 mm transmitter has many power options for optimized battery life and power output. It comes in two versions: the 9 and the 9L. 9L is intended for use where battery life is important, and 9 is ideal for use where size is prioritized. The full range of low, medium, and high power output is available for both variations of the 9 mm tag.

The Thelma Biotel 9 mm acoustic transmitters are intended for use where both size, output power, and long transmitting life are crucial. Manual tracking or automatic monitoring of larger salmon smolt migrating out of fjords is a potential area of use. The 9 mm transmitters are delivered both as continuous pingers and ID transmitters. The customer specifies pulse delay or coded ID and type of encoding scheme, transmitting frequency, and minimum and maximum random delay for ID transmitters.

Four versions of the 9 mm transmitters are available: LP9, MP9, MP9L, and HP, which stand for low(LP), medium(MP), and high power(HP), respectively.