Sodium Analyzers -Analytical Instruments

1. SODIUM ANALYSER
• The sodium electrodes relies on the change in potential arising from a
change in ion concentration .
• This potential change is monitored versus a reference electrode.
• The sodium electrode is a glass electrode similar to pH electrode with
a special glass bulb sensitive to H+ ions.
• This glass bulb has a proprietary composition but contain Na+ ions.
• The bulb is filled with a buffered solution at a fixed level of sodium
ions.

3. SODIUM ANALYSER
• The difference in sodium concentration on both sides of the glass bulb
membrane will be reflected by a change in potential.
• This potential change will be logarithmic with the concentration changes.
• Form this principle it can be concluded that the pH will play a major role in
sodium measurement.
• This point will be addressed as “Proton interference”.
• It is clear that this type of sensor has no “physical zero”.
• Since every sensor can be slightly different in terms of glass formulation or
buffer composition ,easy calibration will be required for accurate
measurement.

4. SODIUM ANALYSER
• All glass electrodes are also known to lose their sensitivity when they
do not see the ion to be measured.
• This is particularly important where sodium electrodes are used or
measuring very low sodium concentration in ultra-pure water
applications.
• Using sodium analysis in the industrial environment requires not only
practical means of addressing the issues of pH, temperature and ISE
responses but also the provision of a means of sampling,calibrating
,controlling flow and controlling pressure in addition to making the
instrument simple to use and easy to maintain.
• https://www.youtube.com/watch?v=CRzJsTcVzcY

5. Silica Analyzer
• Formation of deposition in pipes and on turbine blades
• The sample is prepared for analysis by adding ammonium molybdate
Solution, Suphuric acid and reducing solution with the sample.
• These are mixed well in the mixing vessel with the help of stirrer
and flow rate of each is controlled by the valves which are placed in
each line .
• The mixing vessel solution is emptied to the measuring cuvette where
it is measured and drained completely after the analysis to avoid the
interference with the next analysis.

6. Silica Analyzer
• The analyzer is having two cuvettes, one lamp source and two
photometers the two curettes are namely reference cuvette and
measuring cuvette
• The reference cuvette is used for holding reference solution having
the known concentration of silica
• The lamp source is placed in between measuring cuvette and
reference cuvette, the two photometers are placed on either side of
the cuvette
• The transmitted light rays are detected by the photovoltaic cells. The
output of the two photovoltaic cells drives the differential amplifier
and the amplified signal is read through read out device

7. Silica Analyzer

8. Silica Analyzer

9. Silica Analyzer

10. Dissolved Oxygen Analyzer
• Dissolved oxygen refers to oxygen dissolved in water.
• Its concentration is expressed as the amount of oxygen per unit
volume and the unit is mg/L.
• Biologically, oxygen is an essential element for respiration of
underwater life and also acts as a chemical oxidizer.
• The solubility of oxygen in water is affected by water temperature,
salinity, barometric pressure, etc. and decreases as water
temperature rises.

11. Measurement of dissolved oxygen by
the membrane electrode method
• The membrane electrode method measures a diffusion current or
reduction current generated by the concentration of dissolved oxygen
or partial pressure of oxygen to obtain the concentration of dissolved
oxygen.
• This method is not affected by the pH value of water being measured,
oxidation and reduction substances, color, turbidity, etc. and the
measurement method offers good reproducibility.

12. Membrane electrode method:
• When a sensor is inserted into water, an air layer forms on the
membrane (Teflon membrane).
• The oxygen partial pressure (concentration) in the air layer is in
equilibrium with the concentration of dissolved oxygen in the water.
• The membrane electrode method measures the oxygen concentration
in the gas phase to indirectly obtain the concentration of dissolved
oxygen in water.

13. Galvanic cell method

14. Galvanic cell method
• The membrane has high permeability to oxygen and is constructed so
that the electrodes and electrolyte are isolated from the water being
measured.
• The counter electrode is a base metal and the working electrode is a
noble metal and potassium hydroxide is used as the electrolyte.
• Oxygen passes through the membrane and is reduced on the working
electrode, and so the method measures the reduction current flowing
between both electrodes, which is proportional to the concentration
of dissolved oxygen.