sensors for cond., pH, eH

[Mike O'Kane, P.Eng.]

This may not be directly applicable to the discussion group.  However, we
would appreciate any help or direction the list members can offer.

We are looking for insitu sensors to measure conductivity (to a maximum of
270g/L of TDS), pH, and eH in a "wet" potash mining slimes pond.  We would
like to have the option of connecting all sensors to an existing data
acquisition system although this is not a strict requirement.  The sensors
(including temperature) would be installed laterally from a vertical culvert
into the slimes at different depths.  A number of ponds will be monitored.
Monitoring wells will also be installed which will help address the issue of
sensor "drift" over time.

We have only been able to source pH and eH sensors that are designed for
measuring these parameters in water.  In addition, we understand that
current conductivity measurement technology uses potentiometric methodology
(4-ring) which would not be suitable for measuring conductivity in a "wet"
material.  Is anyone aware of a conductivity sensor which uses the "older"
amperiometric measurement methodology (2-ring) which may be more suitable
for our application?

Thanks in advance for the help.

Mike O'Kane, P.Eng.
O'Kane Consultants Inc.