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LevelVent Field Measurement
LevelVent Ranges
LevelVent Models are rated to a specific submergence depth (Table 1). The choice of model
depends on the accuracy of the level required and the submergence depth. Most important,
your selection should be based on the maximum anticipated water level fluctuation.
LevelVent
Model
Submergence Depth Accuracy
M5
5 m (16.4 ft.)
± 0.3 cm (0.010 ft.)
M10
10 m (32.8 ft.)
± 0.5 cm (0.016 ft.)
M20
20 m (65.6 ft.)
± 1 cm (0.032 ft.)
Table 1 - LevelVent Ranges
Measurement Fundamentals
LevelVent loggers detect both water
(W)
and barometric
pressure
(+B)
.
However
, a vent tube to surface allows
barometric effects on the pressure sensor to be eliminated
(-B)
. Therefore, LevelVent loggers provide readings of the
actual pressure of just water above the pressure sensor zero
point
(A)
.
A = (W + +B) + (-B)
Therefore,
A=W
A
= LevelVent readings
W
= Water column height
+B
= Barometric pressure detected by the pressor sensor
-B
= Barometric pressure applied through the vented cable
Verifying Readings
Compare LevelVent readings
(A)
with a measured depth
to water level value
(d)
(Using a Water Level Meter).
The deployment depth of the LevelVent
(D)
, minus the
manual depth to water measurement
(d)
, should equal the
LevelVent reading:
D - d = A
Note:
The LevelVent logger can withstand over-
pressurization of 2 times the intended range,
e.g. a Model M10 can accommodate a
fluctuation of 20 meters or 60 feet and still
record pressure. However, over-range accuracy
is not guaranteed.
