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issues_with_ph_measurement [07/08/2019 07:05]
pieter
issues_with_ph_measurement [23/09/2019 07:08]
pieter
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   * the calibration cannot be done successfully,    * the calibration cannot be done successfully, 
   * the pH is correctly when measuring buffers but not when measuring some other reference solutions,    * the pH is correctly when measuring buffers but not when measuring some other reference solutions, 
 +  * the measurements are not repeatable,
   * ...   * ...
 +Check this list of possible reasons: [[Guide to troubleshooting|Guide to troubleshooting]]
  
 +===== Check electrode =====
 Many measurement problems arise from the electrode or from a wrong use, rarely from the instrument itself. Therefore it is important to: Many measurement problems arise from the electrode or from a wrong use, rarely from the instrument itself. Therefore it is important to:
   * Make sure there is no **air bubble trapped** in the pH sensitive bulb. If this should be the case, shake it  like a clinical thermometer with the bulb downwards to remove it.   * Make sure there is no **air bubble trapped** in the pH sensitive bulb. If this should be the case, shake it  like a clinical thermometer with the bulb downwards to remove it.
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   * Be aware of **mechanical impacts**.   * Be aware of **mechanical impacts**.
      * Avoid to drop the electrode, use an electrode holder where possible.      * Avoid to drop the electrode, use an electrode holder where possible.
-     * Do not put unnecessary stress on the cable or plug to avoid internal interruptions. +     * Do not put unnecessary stress on the **cable** or plug to avoid internal interruptions. 
         * When having a separate cable, i.e. the electrode can be removed from it, it can be verified using an Ohmmeter. Without Ohmmeter, short-circuit the electrode connector when the cable is connected to the meter, see point 5 in the grey box.         * When having a separate cable, i.e. the electrode can be removed from it, it can be verified using an Ohmmeter. Without Ohmmeter, short-circuit the electrode connector when the cable is connected to the meter, see point 5 in the grey box.
         * When the electrode is fixed to the cable, it is difficult to test it. Look for very irregular behavior when moving the cable.         * When the electrode is fixed to the cable, it is difficult to test it. Look for very irregular behavior when moving the cable.
 +        * Check whether all contacts of the plugs are all bright and clean.
   * Keep your instrument clean, **avoid moisture** on the connectors.    * Keep your instrument clean, **avoid moisture** on the connectors. 
   * Do not store the meter in cold humid environments. If so, and a measurement problem arises, please store it free of connections and packaging in a warm dry environment for a few days and try it again.   * Do not store the meter in cold humid environments. If so, and a measurement problem arises, please store it free of connections and packaging in a warm dry environment for a few days and try it again.
   * Follow the [[http://www.consort.be/wiki/ph_measurement_tips#good_measurement_practices|Good Measurement Practices]] to avoid measurement errors.   * Follow the [[http://www.consort.be/wiki/ph_measurement_tips#good_measurement_practices|Good Measurement Practices]] to avoid measurement errors.
  
-When an error arises, it is best to try to locate the cause first.  
  
 ====== Report a measurement problem ====== ====== Report a measurement problem ======
issues_with_ph_measurement.txt · Last modified: 23/09/2019 07:12 by pieter