YSI 9600 - Manual (Page 12)

CAUTION: The battery lid screws are captive. Do NOT continue to turn them after the
battery lid can be removed.
Loosen 4 battery lid screws
and lift battery lid straight up
• Confirm that the battery pack is present in the compartment, but do NOT connect its battery lead to the
mating connector at this time.
• Replace the battery lid.
After completing the unpacking and inspection sequence outlined above, proceed to Section 2.2 below to
gain a basic understanding of the Model 9600 mode of operation.
2.2 UNDERSTANDING THE 9600 MODE OF OPERATION
The Model 9600 is designed to allow users to monitor the nitrate concentration in environmental water over
long periods of time with minimal maintenance required. It is NOT designed for spot sampling of nitrate
since the minimal interval between samples is 15 minutes. The system operates by the principle of flow
injection analysis (FIA) using a series of precise low-volume pumps to mix an aliquot of the water at an
environmental site with user-prepared reagents that produce a colored solution. The intensity of the color
is measured in a detector cell using a green light-emitting-diode (LED) as the light source and a photodiode
as the detector and this intensity is proportional to the concentration of nitrate in the sample. The detector
cell is also equipped with a reference photodiode to automatically compensate for any changes in LED
intensity during a study. Because the pumps are low-volume, minimal waste is generated by the 9600 FIA
system during field studies and this waste can readily be captured in the containers supplied to prevent
environmental contamination.
It is important to understand that, in its normal configuration with the cadmium column in place, the 9600
measures the sum of the nitrate AND nitrite in the water being monitored. Normally, however, because
the biological process of nitrification is active at most sites, there is very little nitrite in most environmental
water and therefore the 9600 reports its readings as nitrate. Users who are concerned that there is indeed a
significant quantity of nitrite in the water at their monitoring sites should either carry out studies with the
9600 with no cadmium column in place or should collect water samples at the site and perform laboratory
analyses for nitrite to determine if its presence is having a significant effect on the overall accuracy of the
measurement.
Users interface to the Model 9600 via a PC that is running the YSI software designated as NUview
TM
which is supplied with each nitrate monitor as part of the information packet. This software provides a
simple interface for set-up and deployment of the nitrate monitor that is ideal for the vast majority of
studies. Under the standard set-up routine, the user inputs specific information about the pending
YSI Environmental 12 Model 9600 Nitrate Monitor