环境水中物理指标检测方案

Salinity of SurfaceFresh Water Salinity of SurfaceFresh Water Calibration and Analysis 1. Calibrate the cell constant with 1413 uS Conductivity Standard. 2. Rinse the probe with deionized water and gently shake off excess water. Thoroughly rinse cell in thefirst beaker with 1413 pS Conductivity Standard. Place the probe into second beaker filled with thisconductivity standard. Cell should be immersed a minimum of two inches in the solution. 3. Press the CALIBRATE key. 4.Enter the standard value of“1413”using the UP and DOWN arrow keys and the DECIMAL/DIGIT key.5. Press the MEASUREMENT key to accept 1413 uS standard and to move to the measure mode of the meter. 6.Rinse the probe with deionized water and gently shake off excess water. Thoroughly rinse cell with oneor more portions of sample. Place cell in a prepared sample such that it is immersed in a minimum of two inches of solution. 8. Press the MEASURE key on the meter， the ppt icon will flash as the measurement is being made. Theppt icon will become solid and the display value will freeze when a stable reading is achieved. Thisvalue is logged and printed automatically. 9.Repeat steps 7 and 8 for additional samples. Upon completion of samples， rinse electrode withdeionized water and store the electrode according to the instructions in the Electrode Storage sectionof this method note. Introduction This procedure provides the direct salinity reading of surface fresh water. Salinity is the total of all thesalts dissolved in the solution， measured in parts per thousand (ppt). The advanced Orion Dura-Probe"4-electrode Cell Technology and the meter’s enhanced features make this method an ideal choice for plantor field. Recommended EquipmentCat. No.Cond Application Package (includes all items with a Cat. No.)10101281.3-Star portable conductivity meter1214000 2.Conductivity cell013010MD 3. Electrode storage sleeve1210003.4 Field case1210004Required SolutionsCat. No.1.Conductivity Standard， 1413 uS/cm011007 2.Conductivity Standard， 12.9 mS/cm011006 3.Deionized water Calibration Standard Preparation 1.Prepare two beakers with 1413 uS Conductivity Standard. Transfer approximately 55-60 mL of the1413 uS standard into each beaker. The solution in first beaker will be used to rinse the probe beforecalibration. The second beaker will be used for calibration. 2.If the expected results are higher levels of conductivity， follow Step 1 with the 12.9 mS/cmConductivity Standard. 3. If measuring a range of sample conductivities， then a two point calibration can be performed with thetwo standards. Sample Preparation 1. Transfer approximately 55-60 mL sample into a beaker. 2. Repeat this procedure for additional measurements. Results Five aliquots of surface fresh water were collected from a local pond and measured for salinity. Therepresentative results are listed below： Surface Fresh Water Parts per thousand (ppt)* Sample # 1： 0.2 Sample #2： 92 Sample#3： 0.2 Sample # 4： 0.2 Sample # 5： 0.2 Mean： 92 Standard Deviation： 0.00 *For Salinity measurement， the meter must be in ppt result units in Conductivity Setup. Electrode Storage 1 Between measurements and when transporting equipment from the field， keep the probe secured in theprotective sleeve on the meter. 2Upon return to the lab， rinse the probe with deionized water.3For overnight and prolonged storage， the conductivity cell should be stored clean and dry. Equipment Setup Electrode Setup - Conductivity Cell 1. Rinse the probe with deionized water. Gently shake off excess water. For initial meter setup， follow the steps on the Quick Reference Guide that is attached to the meter itself.The Quick Start Guide also contains a layout of the meter keypad for reference. The words in this methodrepresented in all capital letters such as POWER indicate a key on the meter， and words in quotations such as“Unit”indicate information on the meter display. Connect the electrode to the meter. 2 Press the POWER key on the meter to turn the meter on. 3. Note that the arrow on the left of the screen indicates the active line. If the middle line is not active， pressthe LINE SELECTION key to change the selected line to the middle line. Then press the UP or DOWNarrow keys to select the desired conductivity result units. Press the SETUP key to enter Conductivity Setup. 5.Press the LINE SELECTION key to select the middle line， and press the DOWN arrow key to select “tC”which is an abbreviation for temperature compensation (nonlinear， linear， and off). 6.Press the LINE SELECTION key to select the bottom line. Press the UP or DOWN arrow keys to select“nLF”for “tC”. Press the LINE SELECTION key to accept setting. 7.Press the LINE SELECTION key to select the middle line， and press the DOWN arrow key to select“trEF”which is an abbreviation for reference temperature for temperature compensation. 8.Press the LINE SELECTION key to select the bottom line. Press the UP or DOWN arrow keys to select“25”for“trEF”. Press the LINE SELECTION key to accept setting. 9 Press the LINE SELECTION key to select middle line， and press the DOWN arrow key to select “tYPE”which is an abbreviation for Conductivity Cell type. 10. PPress the LINE SELECTION key to select the bottom line. Press the UP or DOWN arrow keys to select “Std"for “tYPE". Press the LINE SELECTION key to accept setting. 11. Press the LINE SELECTION key to select the middle line， and press the DOWN arrow key to select “tdSF”which is an abbreviation for Total Dissolved Solids. 12. Press the LINE SELECTION key to select the bottom line. Press the UP or DOWN arrow keys to select “0.66”for “tdSF" Press the LINE SELECTION key to accept setting. 13. Press the LINE SELECTION key to select the middle line， and press the DOWN arrow key to select“CELL”which is an abbreviation for Conductivity Cell Constant. 14. Press the LINE SELECTION key to select the bottom line. Enter the Cell Constant value of"0.475” using the UP and DOWN arrow keys to change the value of the flashing digit. Press the DECIMAL/ DIGIT key to advance to the next digit. Press the LINE SELECTION key to accept setting. 15. Press the MEASURE key to return to the measurement mode. If all steps were followed correctly the meter display will show three digits in the top line and ppt to the right ofthe top line. The meter and electrode are now ready for calibration. www.thermo.com ofof ofof