其他中物理指标检测方案

DH ofUltra Pure Water orLow Ionic Strength Water Star SeriesMethod Note M-1029-E 03/05 RevB pH ofUltra Pure Water orLow Ionic Strength Water Calibration and Analysis ·pH· Ultra Pure Wateror Low lonicStrength Water·ROSSCombinationpH electrode Introduction 1.Allow all the standards and the samples to attain room temperature for precise measurements since themeasurement is temperature sensitive. 2.Calibrate the meter using the pH 6.97 buffer followed by the pH 4.10 buffer， stirring the standards ata uniform rate. 3.P1lace electrode and Orion° stirrer into beaker with pH6.97 buffer standard such that the electrodetip is fully immersed in the solution. The stirrer should be positioned slightly below the tip of theelectrode. Press the STIRRER key on the meter to turn the stirrer on. Press the CALIBRATE key. There has been a growing interest in making pH measurements in “pure water"： waters in which the totalamount of acid or base is very small， and in which there is a low level of dissolved salts. Measurement inthese pure water samples is more difficult. Although electrodes respond quickly in buffers， in pure waterthe electrode response is often unsatisfactory- slow， noisy， drifty， non-reproducible， and inaccurate. Orion°has developed an easy-to-use method that minimizes the problems encountered when measuring pH inpure waters. The method uses a high quality glass pH electrode and a kit consisting of a pure water ionicstrength adjustor (Pure Water pHisa") and a special set of Pure Water L.I.S. buffers containing the samebackground of Pure Water pHisa. 4.Wait for stable reading (1-2 minutes). Enter standard value of 6.97 using the UP and DOWN arrowkeys and the DECIMAL /DIGIT key. Recommended Equipment Cat.No. 5.Press CALIBRATE key to accept 6.97 standard and press the STIRRER key to turn the stirrer off. 1. 4 Star benchtop pH/cond. meter 1117000 6.Rinse electrode and stirrer thoroughly with deionized water. Gently remove excess solution from theouter sleeve of the electrode by dabbing with a clean paper tissue. Do not wipe or rub the sensingelement of the electrode. 2. ROSS Combination pH electrode 8102BNUWP 3. Orion benchtop stirrer (or magnetic stir plate and bar) 096019 4. Benchtop electrode stand 1110001 7.1Place the electrode and stirrer into beaker with the pH 4.10 buffer standard such that the electrodetip is fully immersed in the solution. The stirrer should be positioned slightly below the tip of theelectrode.Press the STIRRER key on the meter to turn the stirrer on. 5. Beakers (150 mL) 5. Graduated cylinder (100 mL) 8.Wait for a stable reading (1-2 minutes). Enter standard of 4.10 using the UP and DOWN arrow keysand the DECIMAL /DIGIT key. 9P.ress MEASURE key to accept 4.10 standard and to move to the measure mode of the meter. Pressthe STIRRER key to turn the stirrer off. Required Solutions Cat.No. 1. Orion Pure water pH Test Kit 700001 10. Rinse the electrode and stirrer thoroughly with deionized water. Gently remove excess solution fromthe outer sleeve of the electrode by dabbing with a clean paper tissue. Do not wipe or rub thesensing element. Includes Pure Water pH buffer A pH 6.97 700702Pure Water pH buffer B pH 4.10 700402pHisa Adjustor 700003 1mL syringe 11. Place the electrode and stirrer into prepared sample such that the electrode tip is fully immersed in thesolution. Press the MEASURE key on the meter； the stirrer will turn on. The pH icon will flash as themeasurement is being made. The pH icon will become solid and the display value will freeze whena stable reading is achieved. This value is logged and printed automatically and the stirrer turns offautomatically. 2. Reference Filling Solution， ROSS reference filling solution 810007 3. pH Storage Solution 910001 4. Deionized water Calibration Standard Preparation Remember， rinse electrodes with deionized water between measurements. Penetrate each sample to thesame depth to reproduce sample measurement. Upon completion of samples， rinse the elmple meaectrode withdeionized water and store the electrode according to instructions in the Electrode Storage section of thismethod note. 1. Using a graduated cylinder， transfer 100 mL of the pH 6.97 buffer into a 150 mL beaker. 2. Using a graduated cylinder， transfer 100 mL of the pH 4.10 buffer into a 150 mL beaker. Sample Preparation 1. Using a graduated cylinder， measure 100 mL of sample into a 150 mL beaker. With the syringeprovided， add 1 mL of pHisa to this sample solution. Mix sample with Orion° stirrer or add amagnetic stir bar to the beaker and mix with stir plate. 2. Repeat this procedure for additional measurements. ( Environmental Instruments Water Analysis Instruments ) ( 1 66 Cummings C enterBeverly， MA 01915 USA M - 1 0 29-E 03/05 RevE248091-001 ) Toll Free：1-800-225-1480Tel：1-978-232-6000Dom. Fax：1-978-232-6015Intl Fax：978-232-6031www.thermo.com/waterO 2005 Thermo Electron Corporation RegisteredIS O9001：2000 All rights reserved pH ofUltra Pure Water orLow Ionic Strength Water Results Five aliquots of the pure water are measured and the results provide a representative results expected for pH inpure water. Pure Water pH Sample #1： 5.81 Sample# 2： 5.81 Sample #3： 5.80 Sample #4： 5.75Sample # 5： 5.74 Mean： 5.78 Standard Deviation： 0.03 %CV： 0.59 Electrode Storage To ensure a quick response and free-flowing liquid junction， the sensing element and reference junction mustremain wet and not be allowed to dry out. For short-term storage (up to one week)， soak electrode in Orion°pH electrode storage solution. If not available， as a temporary substitute， use about 200 mL of Orion° pH 7buffer with 1 gm KCl added. For prolonged storage， the reference chamber should be filled with the fill hole cover in place. Cover thesensing element and reference junction with the protective cap containing a few drops of pH storage solution.After prolonged storage， prepare the electrode as described in the Electrode Setup section of this method. Equipment Setup Electrode Setup- ROSS° Combination Remove the protective shipping cap from sensing element and save for storage. Clean any salt deposits from exterior by rinsing with deionized water. Uncover filling hole by removing plastic sleeve， and add ROSS° Internal Filling Solution， Orion° No.810007， to electrode. To maintain an adequate flow rate， the level of filling solution must cover the coiland be at least one inch above the sample level when immersed. 4. Place the electrode in the electrode holder and suspend in air for 15 minutes to thoroughly wet thereference junction. Once junction is wet， do not allow the electrode to dry out. 5.Shake down the electrode to remove air bubbles. For initial meter setup， follow the steps in the Quick Start Reference attached to the meter itself. The QuickStart Guide also contains a layout of the meter keypad for reference. The words in this method representedin all capital letters， such as POWER， indicates a key on the meter， and words in quotations such as “Unit”indicates information on the meter display. 2. Connect the stirrer to the meter. 1. 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 top line is not active， press theLINE SELECTION key to change the selected line to the top line. Then press the UP or DOWN arrowkeys to change the measurement mode of the top line to pH. 4.1Press the SETUP key to enter pH setup. Press the LINE SELECTION key to select the middle line. Pressthe UP or DOWN arrow keys to select “rES”， which is resolution. Press the LINE SELECTION key to select the bottom line. Press the UP or DOWN arrow keys to select“0.01”for “rES”which is an abbreviation for resolution or number of significant digits. Press the LINESELECTION key to accept value. 7P.ress the LINE SELECTION key to select the middle line， and press the UP or DOWN arrow key toselect“bUF”which is pH buffer. 8.Press the LINE SELECTION key to select the bottom line， and press the UP or DOWN arrow key toselect“USA”which is US/Orion° buffers. 9. Press the LINE SELECTION key to accept and select the pH setup menu line (top line). 10. 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“pH"to the rightof the top line. The meter and electrode are now ready for calibration. Note： The Orion Benchtop Stirrer must be turned on in General Instrument Setup before analysis， please see the QuickstartGuide for instructions. www.thermo.com of of fof