AML Base X2 - Operational Procedures; Accounting for Atmospheric Pressure Variations; Logging a Profile

User Manual for AML Oceanographic BaseX2
10
Step
Possible Commands
Initialize Memory (erases instrument
memory)
INIT
Set Log File Name
SET LOG filename.txt
Set Instrument Time & Date
SET TIME hh:mm:ss
SET DATE mm/dd/yy
Set Sampling Parameters
SET SAMPLE RATE CONTINUOUS
SET SAMPLE RATE 5/s
SET P INC 1
SET SOUND INC 2
The above table provides example commands only; many additional sampling regimes can be established using
available commands. Please consult the Commands section of the Appendix for full syntax details on the commands
you wish to use.
Accounting for Atmospheric Pressure Variations at the Surface
Climate and altitude changes can create fluctuations in atmospheric (barometric) pressure.
AML's pressure sensors are sensitive enough to detect these variations. When this happens, the
instrument's pressure channel may not read exactly zero when data is taken prior to submersion
in the water. Nearly all absolute pressure sensors experience atmospheric pressure offsets if
they are sufficiently sensitive.
To compensate for this atmospheric pressure offset, AML instruments have the ability to reset
the pressure sensor's zero point. This can be initiated using AML Oceanographic SeaCast
software or a terminal emulator command. The compensation does not affect the calibration of
the pressure sensor and can be turned off or recalculated at any time. The compensation factor
is applied through the entire calibrated pressure range.
Once the atmospheric pressure compensation is applied, it will be applied to all pressure sensor
data until it is turned off or recalculated. The setting is written to memory, so it remains set when
the instrument is powered down.
Using SeaCast
Refer to the SeaCast User Manual for instructions on enabling "Zero Depth."
Using a Terminal Emulator
• Establish serial communications with the instrument on your computer. Refer to the
Communications section of this manual for more information.
• Once connection is established, ensure the instrument is stationary, and is not
submerged in water.
• To turn ON Atmospheric pressure compensation, issue the ZERO ON command. This
will calculate and apply the offset required to compensate for current atmospheric
pressure conditions.
• To turn OFF Atmospheric pressure compensation, issue the ZERO OFF command. This
will disable the offset.
• Issuing the ZERO command again will calculate a new offset based on current
conditions.
Logging a Profile
While there are many variations to profiling workflow based on user requirements, the typical
procedure is as follows: