Oakton 35631-00 Operating Instructions Manual

Oakton 35631-00 Operating Instructions Manual Manual pdf 6 page image

1110pH calibrationWe recommend that you perform at least a 2-point calibration using standard buffersthat bracket (one above and one below) the expected sample range.Preparing for pH calibrationThis meter is capable of up to 5-point pH calibration to ensure accuracy across theentire pH range of the meter. Select from the following buffer options:pH 1.68, 4.01, 7.00, 10.01, and 12.45.The meter automatically recognizes and calibrates to these standard buffer values,which makes pH calibration faster and easier.Be sure to remove the protective electrode storage bottle or rubber cap of theprobe before calibration or measurement. If the electrode has been stored dry,wet the probe in tap water for 10 minutes before calibrating or taking readings tosaturate the pH electrode surface and minimize drift.Wash your probe in deionized water after use, and store in electrode storagesolution. If storage solution is not available, use pH 4.0 or 7.0 buffer.For directions on how to calibrate your meter:• See section 4.3 on pages 11-12 for pH calibration• See section 4.4 on page 13-15 for conductivity and TDS calibration• See section 4.5 on page 16 for Temperature CalibrationPreparing the Meter for CalibrationBefore starting calibration, make sure you are in the correct measurement mode.When you switch on the meter, the meter starts up in the units last used. Forexample, if you shut the meter off in "pH" units, the meter will read "pH" unitswhen you switch the meter on.Do not reuse calibration solutions after calibration. Contaminants in the solution canaffect the calibration, and eventually the accuracy of the measurements. See pages46-47 for information on our high-quality calibration solutions.4. CalibrationImportant Information on Meter CalibrationWhen you recalibrate your meter, old calibration points are replaced on a “pointby point” basis in pH, and on a “range by range” basis in conductivity or TDS.For example:• pH: if you previously calibrated your meter at pH 4.01, 7.00, and 10.01, and yourecalibrate at pH 7.00, the meter retains the old calibration data at pH 4.01 andpH 10.01.• Conductivity/TDS: if you previously calibrated your conductivity meter at 1413μS in the 0 to 1999 μS range and you recalibrate at 1500 μS (also in the 0 to 1999 μSrange), the meter will replace the old calibration data (1413 μS) in that range.The meter will retain all calibration data in other ranges.TDS values are proportional to conductivity values. Note that if you calibrate aTDS value in an equivalent conductivity range, the TDS value will replace theprevious conductivity value, and vice versa.To view current calibration points:• pH: Program P1.0 in the SETUP section, page 26.• Conductivity/TDS: Program P5.0 in the SETUP section, page 32.To completely recalibrate your meter, or when you use a replacement probe,it is best to clear old calibration data by resetting the meter.To reset the meter to its factory defaults:• pH: Program P4.0 in the SETUP section, page 31.• Conductivity/TDS: Program P9.0 in the SETUP section, page 40.NOTE: Resetting the meter will set meter to factory defaults.Conductivity/TDS and pH must be reset separately.4.24.1To calibrate pH:1. If necessary, press the MODE key toselect pH measurement mode. The pHindicator appears in the upper right handcorner of the display.See figure2. Rinse the pH electrode thoroughly withde-ionized water or a rinse solution. Donot wipe the probe; this causes a build-upof electrostatic charge on the glass surface.3. Dip the pH electrode into the calibrationbuffer. The end of the probe must becompletely immersed into the sample. Stirthe probe gently to create a homogeneoussample.NOTE: The temperature element is in theconductivity cell. For temperature compen-sated readings, dip the conductivity cell intothe calibration buffer as well.4.3ATCREADYMEASCpHACONTINUED ON NEXT PAGEA