TROLL 9500 Operator's Manual - Geotech Environmental Equipment

Multi-ParameterWater Quality TROLL ®8 Monitoring TemperatureWhy Monitor Temperature?Water temperature plays an important role in water chemistry, which inturn influences the biological activity and growth of aquatic organisms.In general, the higher the water temperature, the greater the biologicalactivity and the rate of chemical reactions. An important example ofthe effects of temperature on water chemistry is its impact on oxygen.Warm water holds less oxygen than cool water; the maximum amountof oxygen that can be dissolved in the water decreases as watertemperature increases.Artificially high temperatures are often referred to as “thermal pollution,”which may result from discharge of municipal or industrialeffluents. Thermal pollution can have a significant ecological impact.In running waters, particularly small urban streams, elevated temperaturesfrom road and parking lot runoff can be a serious problem forpopulations of cool or cold-water fish.Changes in the growth rates of cold-blooded aquatic organisms andmany biochemical reaction rates can often be approximated by the“Q 10rule,” which predicts that growth rate will double if temperatureincreases by 10°C (18°F) within their “preferred” range.End view of sensor blockKnowledge of water temperature is essential to the measurement ofdissolved oxygen, conductivity (salinity), pH, and many other waterqualityparameters. In limnological studies, water temperature as afunction of depth can be an important indicator. Industrial plants oftenrequire data on water temperature for process use or heat-transmissioncalculations.These are only a few of many reasons for measuring and recordingwater temperature over the short or long term.The Temperature SensorAll models of the Multi-Parameter TROLL 9500 include a permanentlyinstalled, factory-calibrated sensor for measuring solution temperature.Do not try to remove the permanently installedtemperature sensor.The MP TROLL 9500 temperature sensor is the Standard PlatinumResistance Thermometer specified by the ITS-90 (International TemperatureScale of 1990). A platinum resistance thermometer (PRT) isa type of resistance temperature detector (RTD).TIP: After a drop or shock, if the end of the temperaturesensor is slightly bent, it may be carefully bent by hand (notools, please!) back to its original alignment. Note that asevere shock may affect the accuracy of the temperature sensor.Pressure/Turbidityor plugPlatinum Resistance ThermometerTemperatureTROLL 9500 Operator’s Manual 540095110 rev. 007 01/09