issues_with_ph_measurement
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issues_with_ph_measurement [07/08/2019 07:05] pieter |
issues_with_ph_measurement [23/09/2019 07:12] pieter [Check instrument] |
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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. | ||
| Line 15: | Line 18: | ||
| * 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. |
| + | |||
| + | ===== Check instrument ===== | ||
| + | | ||
| * 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. | ||
| + | * Test the instrument following the manufacturer instructions. | ||
| + | |||
| + | ===== Check method/ | ||
| * Follow the [[http:// | * Follow the [[http:// | ||
| - | 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
