Temperature
Testing Parameters
Air and water temperatures also have a great effect on other parameters. Temperature by definition is the measure of heat, and will act as a catalyst in many chemical reactions. As water temperature goes up, the elements in the water react in a different manner than in colder water. Water depth will influence water temperatures a great deal. In shallow water, air temperature has a significant effect on water temperature. Even in deep water, the layer near the surface is greatly effected by air temperature. To fully understand the relationship with temperature and the other components, both air and water temperature need to be taken. Be sure to take air temperature prior to water temperature. If you take the water temperature first, the water left on the thermometer will evaporate and cause cooling, thus giving a false reading. Temperatures of the water greatly effect the organisms living there. Remember, very few of the organisms associated with bodies of water are warm blooded (homoeothermic), most are cold blooded (poikilothermic). To be poikilothermic means that you cannot produce your body cannot produce its own heat. That organism must be adapted to a certain temperature range. Some organisms are tolerant of temperature fluctuations (erysthermal), some are sensitive (stenothermal).
Testing Procedures
Air Temperature
Hang the thermometer using a string or wire out of
the wind and direct sunlight. Do not hold the thermometer directly as our body
temperature can influence the temperature reading. Be sure not to allow any
water or other fluid to get on the thermometer. Evaporative cooling will also
influence the temperature reading. Hold or hang the thermometer for two or three
minutes, but no longer than five. This will allow the thermometer enough time
to adjust. Read the temperature to the nearest 0.5 degree Celsius ( ° C)
and note on the data sheet.
Water Temperature
Immediately after collecting the water sample, place
the thermometer in the container and set aside out of direct sun. Do not hold
the water sample as your hands may begin to heat the water sample. Allow 1.5
minutes to acclimate the thermometer. When reading a thermometer in fluid, do
not remove the thermometer. Take the temperature reading while the thermometer
bulb is submerged in the sample. Otherwise, the temperature will immediately
change according to air temperature and evaporative cooling. Read the temperature
to the nearest 0.5 ° C and note on the data sheet.
