Sonotronics’ depth telemetry transmitters transmit their depth by varying the pulse interval time between pings. For example, a tag at 0psi at the surface may have an interval time of 650ms, and a full scale pressure of 100psi with a corresponding interval time of 2050ms. Depth transmitters come in 50, 100, 200, 300, and 500psi models. The accuracy of these transmitters is +/- 2% of full scale.