Oceanic Data Mask Operating Manual - page 70
70
POSITIONING A TRANSMITTER AND MASK
When installing a Transmitter on a Regulator First Stage (Fig.
55), it is important that it be properly positioned for actual use
with the Mask.
The Transmitter is a Battery powered electronic device that
contains a Pressure Transducer designed to measure Pressure of
a Tank that it is fitted to. It also contains a microcomputer that
converts data from the Pressure Sensor and emits Radio Fre-
quency data signals capable of being received by the electron-
ics of the Mask.
The Transmitter emits a low frequency signal that radiates
outward in a semicircular pattern that is parallel to its length
dimension. A coiled antenna inside the Mask receives the signal
when it is positioned within range of the Transmitter.
Once it is activated by sensing a Pressure of 120 PSI (8.4 BAR),
or greater, it will transmit a signal of sufficient strength to be
received by the Mask at distances up to 3 feet (1 meter).
Link Interruption Underwater
During operation, the Mask (receiving unit) may be moved out of
the signal pattern of the Transmitter, resulting in a temporary
interruption of the transmitted Link signal.
Fig. 55 - TRANSMITTER
POSITIONING