Campbell Scientific CRS451/CRS456 Submersible Water-Level Recording Sensor - Manual (Page 11)

CRS451/CRS456 Submersible Water-Level Recording Sensor
The output reading will not be correct, and the transducer
can be damaged if pressure is twice its pressure rating.
Pressure can be converted to feet of fresh water using the following simple
equation:
1 psi = 2.31 feet of water
For example, the maximum depth with a pressure range of 0 to 7.25 psig is
16.748 feet of water.
6.2 Avoiding Freezing Conditions
Expansion of water due to freezing will irreparably damage the
CRS451/CRS456. The CRS451/CRS456 can be safely deployed in freezing
conditions if the sensor is placed below the frost line. In a lake or channel of
moving water, often the sensor can be placed deep enough to avoid freezing.
In shallow conditions, where the water body is at risk of freezing solid, placing
the sensor in a stilling well that extends below the frost line will protect the
sensor from freezing water.
6.3 Dislodge Bubbles
While submersing the CSR451/CRS456, air bubbles may become trapped
inside the nose cone, causing small, offset errors until the bubbles dissolve.
Dislodge these bubbles by gently shaking the CRS451/CRS456 while under
water.
Hitting the instrument against the well casing or other solid
surface could damage the CRS451/CRS456.
If the bubbles are not removed by rotation and shaking
underwater (or bleeding out the air in a closed system), the
CRS451/CRS456 reading will drift lower by the distance of
the gap as the air is slowly dissolved into the water over
time.
6.4 Well Installation
Braided stainless steel cable (pn 29221-L) is used to lower the instrument to an
appropriate depth and to suspend the CRS451/CRS456 in a well.
With long drops, it may be necessary to use the weighted nose cone (option
–WN).
For surface installations the instrument’s body can be strapped with tie wraps
or tape. Campbell Scientific offers cable ties (pn 7421) to secure the cable. If
installing in a well, fasten the cable to the well head.
CAUTION
CAUTION
CAUTION
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