YSI 6500 Environmental Process Monitor - Manual (Page 8)

Installation Section 2
Two major components make up the 6500 Environmental Monitoring System: the 6500 Monitor
and the 6-Series Sonde that contains the sensors. The sonde is a multi-parameter sensor device
that must be placed in a representative sampling location to monitor desired water quality
parameters in the flow stream. Since the 6500 Monitor may be located considerable distance
from the sonde, a specialized Breakout box and/or Junction Box may be required for your
installation, see Appendix D for Accessories information. See Figures 2 and 3 for diagrams of
the two most common installation configurations.
CHOOSING A SONDE LOCATION
The sonde installation will be determined by the site necessary to obtain water quality readings
which are representative of the bulk flow stream. A suitable location should take a number of
physical and chemical factors into consideration:
9 The sonde must be located in the flow stream where level fluctuations will not expose the
sensing probes to the atmosphere. The sonde sensors must remain submersed at all times
during the monitoring.
9 The sonde must be placed in a well mixed, free flowing area of the process stream. The flow
stream should be representative of the process flow being monitored. For example, if effluent
flow is being analyzed, do not place the sonde ahead of a tank or an area that provides for
extended detention time of the effluent desired for monitoring.
9 Ideally, the sonde should be placed at least three (3) feet away from the sidewall and at least
two (2) feet submersed. For most flow channels, midstream and mid-depth would be the
most representative area for the sonde location.
9 Ideally, the sonde should be placed at an angle within 45
0
of vertical and directed with the
flow direction (see Figure 1). This location will provide for the least stress on the support
arm holding the sonde while minimizing opportunity to collect debris. Placement against the
flow stream or perpendicular to the flow stream also provides accurate monitoring, but
inspection and cleaning may be required more frequently due to increased collection of
debris.
YSI Incorporated 6500 Environmental Process Monitor 4