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2. Rinse the pH probe and temperature probe with deionized water then place in the PH 7 solution. 3. Adjust the meter for the appropriate temperature then read the pH. 4. If required use the "calibrate" adjustment on the meter to correct the instrument to read pH 7• . . S. Rinse the pH and temperature probes with deionized .water and place in the pH 10 solution (note: at Forward landfill groundwater pH is usually above 7 therefore it is appropriate to use the Ph 10 standard. If the pH is below 7 then the pH 4 standard should be used 6. Use the "slope"adjustment to correct the meter to properly read pH 10. 7. Repeat steps 2 to 6 until the meter reads PH.7 and 10 as closely as possible. The calibration process will be recorded on a pH calibration log. Copies of calibration logs for each individuatinstrument ire kept in a binder.at the office. The logs are reviewed periodically _. to assess whether the instrument-is becoming-mom difficult to calibrate and therefore.-needs - adjustment by the manufacturer,.or if new probes are required. Conductivity Meter Conductivity measurement is subject to variations due to temperature and instrument drift. For this reason conductivity meters must be calibrated before and after sampling on each day and at least once more during the day. To calibrate a conductivity meter the instrument reading is adjusted to rears correctly for solutions with a standard conductivity, Standard conductivity solutions arc mixed fresh, according to package instructions, for each sawling event.. Standard solutions for conductivityof 100, 1000, or 1.0,000 umhos/liter,are commercially available. Those standards are purchased fresh and discardecu after shelf life has expired. Shelf lives vary depending on the brand of standards used. If pre-preparedsolution is used,the expiration date of the solution will be noted on the calibration log. 23-433849-F01\231QR323 A-3 July 14,2400 20M Kkkdw4cr,lac.