Onderwerp: Nasa diepte transponder fout na nieuwe antifouling

CHANGING THE GAIN DELAY SETTING
The Clipper Echosounder measures the depth beneath the
transducer by timing the delay between the transmitted ultrasonic
pulse (the “ping”) and its returning echo from the bottom, The echo
from nearby objects is much stronger than from more distant
objects, and so the Clipper Echosounder has swept receiver gain
sensitivity so that weaker (more distant) echoes are detected as
reliably as those from short range. However, reflections from
nearby turbulence or bubbles may sometimes be confused with
those from the bottom. To prevent nearby reflections from being
misinterpreted, sweeping the gain can be delayed until a pre-set
depth is reached. The delay is called the sensitivity threshold, and
can be viewed at any time during normal operation by pressing the
SET button. Pressing SET again returns to normal echosounding.
The sensitivity threshold can be changed if required to minimise false
detections at short range. The factory pre-set sensitivity threshold is
zero, but it can be increased in 0.1m (0.5ft.) steps, depending on the
configuration of the unit, up to a maximum of 5m (1 6.5ft.). Press SET
to enable sensitivity threshold changes. The DEEP and SHALL
buttons then make the sensitivity threshold deeper and shallower
respectively within the available range. Pressing SET again to return
to normal echo-sounding also stores the revised sensitivity threshold
in memory, so the unit always operates with the new setting.