饮用水中物理指标检测方案

ORP ofDrinking WaterORP ofDrinking Water ORP ofDrinking Water Star SeriesMethod Note M-1004-E 03/05 RevB ·OxidationReductionPotential (ORP)·Drinking Water·lon SelectiveElectrode (ISE)or ORP TriodeTM Introduction The Oxidation Reduction Potential or ORP is an important water chemistry parameter， providinga measurement of the oxidizing and reducing capability of the water. The Orion° ORP TriodeTM9180BNMD can be used in the drinking water industry monitoring chlorine and other oxidants. Recommended Equipment Catalog# 1. 4 Star benchtop pH/ISE meter11150002. Epoxy Refillable ORP TriodeTM9180BNMD3. Magnetic stir plate and bar4. Orion benchtop electrode stand11100015. Beakers (150 mL)6. Graduated cylinder (100 mL)Required SolutionsCatalog #1. ORP standard solution967901 2. Reference electrode filling solution， 5 *60 mL 900011 3. Deionized water Calibration Standard Preparation 1. Using a graduated cylinder， transfer 100 mL of the ORP standard into a beaker. Sample Preparation 1. Using a graduated cylinder， measure 100 mL of the drinking water sample into a beaker.2. Repeat for additional measurements. Results Five aliquots of drinking water were collected from a faucet and the oxidation-reduction potential ismeasured. The table below provides data for ORP in this drinking water sample. Drinking Water mVE.. Sample #1： 546.9 Sample #2： 547.3 Sample #3： 555.3 Sample # 4： 555.0 Sample #5： 559.4 Environmental InstrumentsWater Analysis Instruments166 Cummings CenterBeverly， MA 01915 USAM-1004E03/05 eYB248064-001 Toll Free： 1-800-225-1480Tel：1-978-232-6000Dom. Fax：1-978-232-6015IntlFax：978-232-6031www.thermo.com/waterO 2005 Thermo Electron Corporation Registered Mean： 552.8 IS O 9001：2000 Standard Deviation： 5.47 %CV： 0.99 All rights reserved 4 of 4 Electrode Storage For brief storage periods (up to one day)， the electrode may be kept in deionized water. For longer storageperiods (more than one day)， rinse the electrode with deionized water， drain filling solution from chamber， flushout with deionized water and store dry. Equipment Setup Electrode Setup 1. Remove the electrode protective cap and keep the cap for storage. 2. Unplug the electrode fill hole cover on the electrode body. 3. Lift the filling solution bottle’s spout to a vertical position. 4. Fill the electrode chamber up to a level just bellow the fill hole. 5. Shake down the electrode as you would with a thermometer to remove air bubbles. Meter Setup For initial meter setup please follow the steps in the Quick Start Guide which is attached to the meter itself.The Quick Start Guide also contains a layout of the meter keyboard for reference. Please note words in allcapitals， such as POWER， indicates a key on the meter， and words in quotations such as “Unit”indicates adisplay on the meter screen. 1.Connect the electrode to the meter. 2Press the POWER key on the meter to turn meter on.3 Note that the arrow on the left of the screen indicates the active line. If not the top line is not active， pressthe LINE SELECTION key to change the selected line to the top line. Then press the UP or DOWNarrow keys to change the measurement mode of the top line to RmV. If all steps were followed correctly，the meter display will show “RmV"to the right of the top line. The meter and electrode are now ready forcalibration.1. Calibration and Analysis 1.Allow standard and the samples to attain room temperature for precise measurements since themeasurement is temperature sensitive. 2. Place the electrode into the beaker with ORP standard such that the electrode tip is fully immersed in theATFsolution. Press the CALIBRATE key. 3 Wait for a stable reading (1-2 minutes). When meter is ready， the measured mV value is converted to EHvalue. The expected value is located on the back of the ORP standard bottle. 4 Adjust mV reading to EH from the table below using the UP and DOWN arrow keys and the DECIMAL/DIGIT key. (C) En(mV) 0 +438 5 +435 10 +431 15 +428 20 +424 25 +420 30 +415 35 +411 40 +406 45 +401 50 +396 5. Press the MEASURE key to move to the measure mode ofthe meter. 6.Rinse electrode， temperature probe， and stirrer thoroughly with deionized water. 7. Place the probes and stirrer in a prepared sample such that the electrode tip is fully immersed in thesolution. Press the MEASURE key on the meter. The RmV icon will flash as the measurement is beingmade. The RmV icon will become solid and the display value will freeze when a stable reading is achieved.This value is logged and printed automatically. 8.Repeat steps 6 and 7 for additional samples. ( Upon completion of samples， rin s e electrode with dei o nized water and s tore the elec t rode acco r ding to i nstructions in the Electrode Storage se c tion of this me t hod note. ) www.thermo.com of of of