Precautions and working principle of PH analyzer during use
PH Analyzer Notes:
1. When the instrument is installed, it is required to select accurate test reagents.
2. Do not inhale air bubbles when the instrument inhales the sample, otherwise the results will be unreliable.
3. The 220V voltage in the back box of the instrument is dangerous to personal safety. Do not open the back cover of the instrument before unplugging the power plug.
4. If the instrument is working in the online mode, please do not operate it in thunderstorm weather to avoid accidents.
working principle:
The online pH analyzer mainly uses the ion selective electrode measurement method to achieve accurate detection. Electrodes on the instrument: pH and reference electrodes. The pH electrode has an ion-selective membrane that reacts with the corresponding ions in the sample to be tested. The membrane is an ion exchanger, and the potential between the liquid, the sample and the membrane can be detected by reacting with the ion charge to change the membrane potential. The difference between the two potentials detected on both sides of the membrane will generate a current. The sample, the reference electrode, and the reference electrode fluid form one side of the "loop", the membrane, the internal electrode fluid, and the internal electrode on the other side.
The difference in ionic concentration between the internal electrode solution and the sample generates an electrochemical voltage across the membrane of the working electrode, which is led to the amplifier through the highly conductive internal electrode, and the reference electrode is also led to the location of the amplifier. A calibration curve is obtained by measuring an accurate standard solution of known ion concentration to detect the ion concentration in the sample.
When the measured ion in solution contacts the electrode, ion migration occurs in the aqueous layer of the ion-selective electrode matrix. The charge change of the migrating ions has a potential, thus causing a change in the potential between the membrane surfaces, creating a potential difference between the measuring electrode and the reference electrode. Ion-selective electrode, the electrode contains an electrode solution with a known ion concentration, which penetrates the corresponding ions in the sample through the ion-selective electrode membrane, thereby generating a membrane potential on both sides of the membrane, and the ion concentration in the sample is not used. Also, by measuring the magnitude of the potential signal, the concentration of ions in the sample can be measured.
