Pulsar dBi-M, Инструкция по эксплуатации

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PULSAR MEASUREMENT
45
P860 Sound Velocity
This option allows for the velocity of sound to be changed according to the
atmosphere the transducer is operating in. By
default, the velocity is set for
342.72m/sec which is the speed of sound travelling in air at a temperature
of 20
o
C .
The table below gives details of the velocity of sound in various gaseous
atmospheres in all cases the velocity indicated is that in a 100% gaseous
atmosphere at 0
o C. In atmospheres less than 100% it may be necessary to
check the level indicated at near empty and near full and compare with the
actual level, several times, then adjust the
Sound Velocity accordingly to
obtain an accurately displayed reading.
OPTION DESCRIPTION
Chlorine 206 m/sec.
Argon 308 m/sec.
Oxygen 316 m/sec.
Air 331.5 m/sec.
Ammonia 415 m/sec.
Methane 430 m/sec.
Helium 435 m/sec.
Neon 965 m/sec.
P645 Vapour Temperature Compensation
The sound velocity in air increases or decreases at a uniform rate of
60cm/sec. per
o C, however in atmospheres other than air it will change at a
different rate.
This option allows the rate of change in cm/sec. per
o C to be set according
to the atmosphere and temperature present. The level indicated, should be
compared with the actual level, several times, then
Vapour Temperature
Compensation adjusted accordingly, to obtain an accurately displayed
reading. Default = 60 cm/sec. per o C