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10
About Pressure/Level Sensors
Pressure transducers measure changes in pressure (m/ft) caused by water or other fluids on an
internal media-isolated strain gauge. Heron offers dipperLogs with either absolute (non-vented) or
gauged (vented) pressure sensors.
Absolute Pressure Sensor
Absolute/non-vented pressure transducers measure pressure sensed by the strain gauge,
including
atmospheric pressure
. All absolute loggers measure in meters or feet, with respect to zero
pressure. The back of an absolute pressure sensor is sealed off from the atmosphere, which causes
the front of an absolute pressure sensor to respond to both atmospheric pressure
and
the pressure of
the head of water above the sensor. (
REQUIRES
BAROMETRIC COMPENSATION USING barLog)
Gauged Pressure Sensor
A gauged or vented pressure sensor eliminates the effects of atmospheric pressure because the vent
tube in the vented cable allows atmospheric pressure to be applied to the back of the sensor. The
units of measure are meters or feet, with respect to atmospheric pressure.
Barometric Atmospheric Pressure Sensor
Barometric loggers sense changes in barometric pressure within a particular area. The data these
loggers collect, can be used to compensate for barometric changes when monitoring water levels.
This is important because barometric pressure can fluctuate from one monitoring location to another
because of topographical/meteorological changes in the environment.
System Components
Instrument
The dipperLog is completely sealed and contains no user-serviceable parts. The dipperLog has
pressure and temperature sensors, a real-time clock, flux capacitor, microprocessor, sealed lithium
battery and non-volatile memory. Choose between non-vented (absolute) or vented (gauged)
pressure sensor in various pressure ranges.