13
ANALOG DISPLAY UNIT
CORRECTION DIAGRAM AT EXTREME TEMPERATURES
Doppler Speed Log DS-80
CORRECTION FACTOR FOR ANALOG DISPLAY MF-22A-1
Example:
If the analog speedometer reads 14.2 kt at a temperature of –15
°
C, the correct speed
through the water is 15 kt. Failure of correction in low temperature can result in a maximum
error of –0.8 kt or 5.3% for 14.2 kt readout. IMO limit of
±
2% is exceeded over 10.0 – 30.0 kt
reading but correction by this graph brings a correct measurement.
At +55
°
C, an error of +0.0 kt (+2.7%) occurs at a speed of 30 kt; no other point IMO limit of
±
2% is exceeded.
When the digital display and analog display readouts are different, take precedence of the
digital readout. At temperatures 0
°
C to 50
°
C, the speedometer never exceeds the IMO
limits.