In-Situ TROLL 9500 Operators Manual User Manual
Page 119
114
TROLL 9500 Operator’s Manual
0095110 rev. 007 01/09
The chloride sensor is now calibrated and ready to use.
TIP: You can look at the calibration report right after
calibrating, or at any time. See “Calibration History” in
Section 10 for details.
Options for storing sensors:
The sensor should calibrated immediately before use. If storage is
necessary, remove the sensor from the instrument and immerse in 35
ppm Cl solution, for later use in the low chloride range, or 355 ppm Cl
solution, for use in the high range.
SENSOR SLOPE AND OFFSET
The expected slope for a new sensor is about 57 (± 2) mV per decade
of concentration (ppm). The calibration curve begins to deviate from
linear at about 10 ppm. The sensor’s zero offset is recalculated with
each single-point calibration.
UNITS AND CALCULATED MEASUREMENTS
Chloride ion concentration is reported in ppm (equivalent to mg/L). No
calculated measurements are available.
USAGE RECOMMENDATIONS AND CAUTIONS
Chloride sensor
/PERATING
½#
Pressure Rating
100 psi (70 m, 231 ft)
pH range
2 to 12
Do not submerge the chloride sensor deeper than 231 ft
(70 m).
pH EFFECTS
The sensor’s pH range is that range over which a change in pH will
not cause a significant change in the measured voltage. It is the
plateau on a graph of pH against mV at constant concentration of the
detected ion. Outside this range, a change in pH may cause a signifi-
cant change in the measured mV.
POTENTIAL INTERFERENCES
The table on this page lists possible interfering ions that cause 10%
error at various levels of Cl
–
.
sensor
removal
tool
SENSOR CARE AND HANDLING
SENSOR REMOVAL
To remove the sensor, position the yoke of the sensor
removal tool at the point where the sensor meets the
sensor block and pry the sensor upward.
MAINTENANCE/INSPECTION/CLEANING
If a film should form on the top of the membrane, use a swab to
remove it, followed by a rinse in deionized water and soaking for a few
minutes in a solution of 35 ppm or 355 ppm Cl.
To avoid depletion of the reference solution, do not allow the sensor to
soak in pure water for more than a few minutes at a time.
The electrode is not customer-refillable.
STORAGE
Store the sensor immersed in 35 or 355 ppm Cl solution, depending
on usage requirements. For longer-term storage, it may be rinsed and
stored dry to avoid depletion of the reference solution.
Ion
100 ppm Cl
–
10 ppm Cl
–
1 ppm Cl
–
OH
–
8000
800
80
NH
3
12 1.2
0.12
S
2
O
3
2–
1 0.1
0.01
Br
–
0.3
0.03
0.003
S
2–
10
-4
10
-5
10
-6
I
–
5x10
-5
5x10
-6
5x10
-7
CN
–
2x10
-5
2x10
-6
2x10
-7
Complexes with BI
3+
, Cd
2+
, Mn
2+
, Pb
2+
, Sn
2+
, Tl
3+
and reduc-
ing agents
SECTION 16: CHLORIDE