Appendix; Troubleshooting; Specifications - Metria M21 Manual De Instrucciones

• Salt deposits: Soak the electrode in warm tap water to dissolve deposits, then thoroughly rinse with distilled water.
• Oil or grease: Wash the glass sensitive membrane of electrode in some detergents and water. If necessary, use the alcohol
to clean, then rinse with distilled water. Place the electrode in the 3M KCL solution for at least 30 minutes.
• Protein deposits: Prepare a 1% pepsin solution in 0.1M of HCL. Place the electrode in the solution for 10 minutes. Rinse the
electrode with distilled water.
• Clogged reference junction: Heat a diluted KCl solution to 60°C to 80°C. Place the electrode into the heated solution for
about 10 minutes. Allow the electrode to cool in some unheated KCl solution.
If stored and cleaned properly, the electrode should be ready for immediate use. However, a dehydrated glass sensitive membrane
may cause sluggish response. To rehydrate the sensitive membrane, immerse the electrode in a pH4.01 buffer solution for 10 to
30 minutes. If this fails, the electrode requires activation.
1. Soak the electrode in 0.1M HCl for 5 minutes.
2. Remove and rinse with distilled water, then place in 0.1M NaOH for 5 minutes.
3. Remove and rinse again, and soak in 3M KCL solution for at least 30 minutes.
ORP electrode
• General deposits: Rinse the electrode with distilled water, store the electrode into the 4M KCL solution.
• Inorganic deposits: Soak the electrode in 0.1M HCl for 10 minutes. Remove and rinse with distilled water, then place in
alcohol for 5
minutes. Remove and rinse again, soak the electrode in pH4.01 buffer solution for 30 minutes.
• Oil or grease: Wash the electrode in some detergents and water. Place the electrode in the 4M KCL solution for at least 30
minutes.
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Appendix

Appendix

Troubleshooting

Fault
Drifting erratic
readings

Specifications

pH
Possible Cause
Electrode dried out
Measured value exceeded the allowed
range
Electrode fault
Buffer problem
Electrode has expired
Model
Range
Corrective Action
Soak the pH electrode in 3M KCL solution at least 30
minutes
Check the electrode and sample
Check the electrode whether clogged, contaminated or
broken
Use freshly prepared pH buffers to calibrate meter
Replace pH electrode
METRIA M21
-1.00 ~ 15.00pH