In-Situ Aqua TROLL 100 and 200 Operators Manual - Manual (Page 59)

Page 59 Aqua TROLL Operator’s Manual
pressure. Vented sensors thus exclude the atmospheric or
barometric pressure component.
This difference between absolute and gauged measurements
may be represented by a simple equation:
P
gauge
= P
absolute
– P
atmosphere
Pressure, Depth, and Level
Output options for pressure measurement are completely
software-selectable. Each log configuration presents the
following choices:
• Pressure in psi or kPa
• Depth in feet or meters
• Water Level with a reference (an “offset”)
4 Surface Elevation: positive up
4 Depth to Water (drawdown): positive down
For Depth and Level, the software presents additional options:
• The type of measurement you intend to log (the “output”)
• The Level Reference you intend to use
• The specific gravity of the water in which the device will be
deployed:
4 Choose a fixed value for fresh, brackish, or saline water, or
4 Enter a custom specific gravity value, or
4
Choose Fixed density with gravitational compensation for
a pressure-to-level conversion that compensates pressure
readings for fluid density and local gravitational factor
(based on your latitude and elevation), or
4
Choose Dynamic density with gravitational compensation,
which will allow the software to dynamically compute
specific gravity using density measured by the conductivity
sensor and local gravitational factor.
TIP: For more
on the differences
between Absolute
(non-vented) and Gauged
(vented) sensors, see the
technical note on the In-Situ
software/resource CD, or www.
in-situ.com.
Section 6: Pressure & Level