In-line process turbidity meters

Hi all,
We have a requirement for an in-line process turbidity meter to be used in a
polishing filter application.  Generally the liquid passing through the
polishing filter is very clean.  However if a break through occurs (ppm
level particulates are found in the clear solution), then we need to take
corrective action (namely divert to another tank or recirculate the stream).

Most turbidity meters I have found are used in water / wastewater
applications and measure turbidity in NTU.  This is not good enough for our
requirements.  So far I have found only one instrument from Optek which uses
light scattering detectors to measure process turbidity.

Does anyone know other instruments (type or manufacturer) that will be
suitable for measuring turbidity (presence of particulates at ppm level) and
can be used in-line?  A number of labaratory or bench type instruments are
available, but we need one that can be installed in the field for continuous
monitoring application.
Thanks in advance for all suggestions and pointers.
Regards,
Raj Sreenevasan