Gluing the transmitter

Special glue is used to stick the Platform Transmitter Terminals (PTT) to the seals’ fur. The glue sets quickly, does not give off heat when setting and is slightly flexible when it is set.

Often a second transmitter is attached. This transmitter is a VHF transmitter and is smaller and sends off a signal at a very high frequency. It helps the scientists to find the seal again. Each VHF transmitter pulses on a different frequency. Using a VHF receiver and a small, hand-held antenna, scientists can hear the pulse from the VHF transmitter. The pulse sounds louder when the antenna is pointing in the direction of the transmitter. The pulse cannot be heard when the antenna is pointing side-ways to the transmitter.