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SOP NUMBER 8.0 <br />Page 3 of 10 <br />Field Parameter Measurements <br />1. If the pH is measured in a container, rinse the sample container with deionized water and <br />then rinse it three times with the water to be sampled prior to measurement. If using an in- <br />flow multi-measurement system, measurements are continuously displayed. <br />2. Rinse the pH probe with deionized water. Be sure to protect the fragile glass bulb at the end <br />of the probe from damage. <br />3. Immerse the electrode in the water, allow the pH to stabilize, and monitor the drift of the <br />instrument. Do not immerse the electrode above the top of the pH probe. <br />4. When the pH reading stabilizes, record in the field logbook the temperature to the nearest <br />0.1 °C and the pH reading to the nearest 0.01 unit. <br />5. Between measurements, store the electrode in pH electrode storage solution or equivalent <br />solution, if possible, or put a cotton swab soaked in electrode solution in the protective cap of <br />the electrode. <br />6. Decontaminate the pH meter/in-flow multi-measurement system and associated equipment in <br />accordance with SOP No. 10.0, Decontamination of Sampling Equipment. <br />QC requirements for pH measurements are provided in Section 5.3. <br />5.2.2 Specific Conductivity Meter <br />Conductance is a measure of the ability of an aqueous solution to conduct electrical current and <br />is expressed in reciprocal ohms (mhos). The International System of Units uses the siemen(s) to <br />represent mhos. Calibration procedures are to be conducted according to the manufacturer's <br />instructions. Record time, temperature, and instrument response in the field logbook. General <br />calibration procedures for Powertech's on-site equipment are described in Attachment 1 <br />(Calibration of Powertech Field Instruments). <br />The procedures for measuring conductivity are as follows: <br />1. If the conductivity is measured in a container, rinse the sample container with deionized <br />water and then rinse it three times with the water to be sampled prior to measurement. Rinse <br />the probe with deionized water. If using an in-flow multi-measurement system, <br />measurements are continuously displayed. <br />2. Insert the probe into the sample. <br />3. Allow the reading to stabilize before recording measurements. <br />4. Record in the field logbook the conductivity, the units of measure, any scale multipliers and <br />temperature of the sample. <br />5. During normal use, rinse the probe thoroughly with deionized water between measurements <br />to minimize the buildup of interfering substances on the probe element. <br />6. Decontaminate conductivity meter/in-flow multi-measurement system and associated <br />equipment in accordance with SOP No. 10.0, Decontamination of Sampling Equipment. <br />QC requirements for conductivity measurements are provided in Section 5.3. <br />Powertech <br />4/23/2007 <br />Rev SOP 8-1 JAB <br />8-3 <br />R Squared Inc