In-Situ TROLL 9500 Operators Manual - Manual (Page 111)

106
TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
Specialized calibration kits are available for calibrating the ammonium
sensor for low-range and high-range measurements:
Low range: two quarts each 14 ppm and 140 ppm
High range: two quarts each 140 ppm and 1400 ppm
RECOMMENDED CALIBRATION FREQUENCY
Ion-selective electrodes are inherently unstable and drift is quite
normal. To achieve the most accurate sensor response, we recom-
mend a complete three-point bithermal calibration once a week, with a
single-point calibration daily or after 4-6 hours of use.
PREPARING TO CALIBRATE
You will need:
s
sensors or plugs in the other sensor ports
s
s
the range you expect to measure. When performing a multi-point
calibration, begin with the lowest-concentration solution.
s
tainer of ice large enough to hold the Cal Cup (and stirrer, if used).
s
field—for example, in stagnant or very slowly moving water. The
MORE
AMMONIUM CALIBRATION PROCEDURE
1. Rinse the Cal Cup and front end of the MP TROLL 9500 in clean
water. Shake to dry.
For best results, follow this with a rinse in a portion of the selected
calibration solution. Discard the rinse solution.
2. Insure the black PVC base (or the stirrer) is attached to the Cal
Cup, and fill the Cal Cup to the fill line with the selected calibration
solution.
s
point calibration.
s
as a guide.
s
3. Insert the front end of the MP TROLL 9500
into the open end of the Cal Cup. Thread the
Cal Cup onto the body until seated against the
o-ring, then back off slightly to avoid overtight-
ening.
To stabilize the instrument, you may wish to
use a calibration stand or other support.
4. Connect the MP TROLL 9500 to a PC and
establish a connection in Win-Situ 4 or Pocket-
Situ 4. Win-Situ screens are illustrated here.
The Pocket-Situ interface is similar, with the
Navigation tree at the top of the screen and
the Information pane below it.
5. Select the MP TROLL 9500 in the Navigation
tree.
The software will automatically detect and
display the installed sensors. If one or more
sensors is installed in the wrong port, an error
message will be displayed. Simply remove
the sensor and install it in the correct position,
then “refresh” the device before continuing.
6. Select Ammonium in the Parameters list. The sensor serial number
(SN) and recent calibration information is displayed.
7. Select Calibrate.
6
7
SECTION 15: AMMONIUM
3
Cal Cup
Stirrer
(optional)