be used to automatically compensate for temperature changes in the solution. For process solu-
tions whose temperature varies by more than a few degrees automatic temperature compensation
is essential for accurate readings. For example water varies its conductivity at the rate of 2%/
o
C.
1.3
Cell Installation
When installing conductivity cells it is important to locate the cell in a position where the pipe is
always completely full. The cell electrodes must be in complete contact with the water sample. If
air is trapped around the cell electrode it will cause errors in the measurement. If oil, grease or
any insulating material is allowed to build up on the electrode surface measurement errors will also
occur.
TBPS cells are suitable for installation into non
metallic pipework. Ideally the cell should be in-
stalled from the side of the fitting. This method
is less likely to be subjected to trapped air. The
“T” fitting should be modified to allow the face
of the cell to be flush with the inside of the fitting
or pipe wall. It is acceptable for the cell to be
slightly recessed when the cell is installed from
the side of the fitting. Alternatively a 3
/
4” BSP
hole may be drilled/threaded into the side of a
fitting such as an existing elbow or “T” fitting.
It is acceptable to install the cell from the top
or bottom of the pipe or fitting provided care is
taken to prevent air pockets or build up of sed-
iment. In applications where the pipe diameter
is less than 50mm the reduced sample volume
around the cell electrodes may affect the accu-
racy of the reading. In these applications in-line
calibration correction is recommended. For in-
stallation into the side wall of a tank, vessel etc.
the information above applies.
PM4COMAN-2.2-1
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