In-Situ TROLL 9500 Operators Manual - Manual (Page 61)

54
Multi-Parameter
Water Quality TROLL ®
TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
8 MONITORING TEMPERATURE
Pressure/Turbidity
or plug
Temperature
End view of sensor block
Platinum Resistance Thermometer
WHY MONITOR TEMPERATURE?
Water temperature plays an important role in water chemistry, which in
TURN
Artificially high temperatures are often referred to as “thermal pol-
lution,” which may result from discharge of municipal or industrial
EFmUENTS
Changes in the growth rates of cold-blooded aquatic organisms and
many biochemical reaction rates can often be approximated by the
“Q
10
rule,” which predicts that growth rate will double if temperature
INCREASES
Knowledge of water temperature is essential to the measurement of
dissolved oxygen, conductivity (salinity), pH, and many other water-
quality parameters. In limnological studies, water temperature as a
function of depth can be an important indicator. Industrial plants often
require data on water temperature for process use or heat-transmis-
sion calculations.
These are only a few of many reasons for measuring and recording
water temperature over the short or long term.
THE TEMPERATURE SENSOR
All models of the Multi-Parameter TROLL 9500 include a permanently
installed, factory-calibrated sensor for measuring solution tempera-
ture.
Do not try to remove the permanently installed
temperature sensor.
The MP TROLL 9500 temperature sensor is the Standard Platinum
Resistance Thermometer specified by the ITS-90 (International Tem-
perature Scale of 1990). A platinum resistance thermometer (PRT) is
a type of resistance temperature detector (RTD).
TIP: After a drop or shock, if the end of the temperature
sensor is slightly bent, it may be carefully bent by hand (no
tools, please!) back to its original alignment. Note that a
severe shock may affect the accuracy of the temperature sensor.