YSI 6500 Environmental Process Monitor - Manual (Page 9)

Installation Section 2
Figure 1 Sonde orientation
Stream
Sonde
Not drawn
to scale.
If the sonde is to be utilized in monitoring for results of chemical feeds and resulting chemical
reactions, sufficient downstream mixing and reaction time should be provided prior to insertion of
the sonde for monitoring. If pH adjustment is necessary, the sonde location should provide for
sufficient mixing and reaction time upstream of the location. Thus, if you question the ideal
location for monitoring, check your installation by manually testing upstream and downstream of
the sondes proposed location. It may prove that you can utilize “less-than-ideal” sonde location
in the flow stream, but take advantage of the location supports for mounting, proximity to the
monitor or other factors that may facilitate the installation.
The flow stream should be as free as possible of debris (e.g., algae) which could collect on the
sonde and cause erroneous readings.
Remember that this is an on-line device that is measuring actual conditions in real time.
Composite sampling for pH, for example, will not match on-line monitoring. Therefore, pH
values recorded by the chart recorder and/or plant control system connected to the 6500
Environmental Monitoring System cannot be averaged to equal the pH of the composite sample.
CHOOSING A MONITOR LOCATION
The sonde is a primary device that measures conditions in the flow stream and transmits a low
voltage signal to the 6500 Monitor. The sonde is attached to a cable that is equipped with a
“military grade” watertight connection to the monitor or optional breakout box.
Several optional accessories are available from YSI to make the 6500 Monitor extremely
versatile. The YSI #6502 Breakout Box is an enclosure for the connections interface between the
sonde cable(s) and customer supplied wiring and conduit which enables the sensor connection to
the monitor to be extended up to 250 feet. The YSI #6503 Breakout Box is the same as #6502,
but is also CE compliant for European users. The YSI #6504 Breakout Box is similar to the above
description, but can also handle two sondes. These Breakout Boxes makes it possible to install the
monitor in a location and environment different than the sonde(s). A YSI #6508 Junction Box is
also needed if the 6500 Monitor is installed with multiple sondes, or if a single sonde is farther
than 6 feet away.
YSI Incorporated 6500 Environmental Process Monitor 5