Filter contamination measuring device, filter assembly including the same, and filter contamination measuring method using the same
A filter contamination measuring device includes: a working electrode adjacent to a first surface of a filter, the filter configured to adsorb an ionic material of a first polarity, a counter electrode disposed on the other surface of the filter, a potentiostat configured to apply a voltage of a second polarity to the working electrode for a predetermined period of time, and to measure current output from the working electrode. The potentiostat is configured to increase the voltage over the predetermined amount of time. The filter contamination measuring device further includes a controller configured to calculate a maximum current attained during the predetermined amount of time and a corresponding voltage value, and to determine the type and concentration of the ionic material based on the maximum current and the voltage value.
1. A filter contamination measuring device comprising:
a working electrode disposed adjacent to a first surface of a filter, the filter configured to adsorb an ionic material of a first polarity;
a counter electrode disposed adjacent to a second surface of the filter, the second surface opposite to the first surface;
a potentiostat configured to apply a voltage of a second polarity, that is opposite to the first polarity, to the working electrode for a predetermined period of time, and to measure current output from the working electrode during the predetermined period of time; and
a controller configured to:
calculate a maximum value of the current obtained during the predetermined period of time based on current measured by the potentiostat,
calculate a value of the voltage applied by the potentiostat at the maximum value of the current,
calculate the type and concentration of the ionic material from the voltage value, and
compare the type and concentration of the ionic material with a reference value to determine whether the filter is contaminated,
wherein the potentiostat is configured to linearly increase the voltage applied to the working electrode during the predetermined period of time.
2. The filter contamination measuring device of claim 1 , wherein the controller calculates a change curve of the current based on the current measured by the potentiostat, and calculates the maximum value of the current and the voltage value from the change curve of the current.
3. The filter contamination measuring device of claim 1 , wherein the working electrode is spaced apart from the first surface of the filter, and wherein the counter electrode is spaced apart from the second surface of the filter.
4. The filter contamination measuring device of claim 1 , wherein the working electrode contacts the first surface of the filter, and wherein the counter electrode contacts the second surface of the filter.
5. The filter contamination measuring device of claim 1 , further comprising a reference electrode disposed adjacent to the counter electrode and connected to the potentiostat.
6. The filter contamination measuring device of claim 5 , wherein the working electrode and the counter electrode are made of a first material, and
wherein the reference electrode is made of a second material different from the first material.
7. The filter contamination measuring device of claim 1 , wherein the filter is a membrane filter.
8. A filter assembly comprising:
a housing having an inlet through which a fluid containing an ionic material of a first polarity is introduced and an outlet through which the fluid is discharged;
a filter installed between the inlet and the outlet in the housing configured to remove the ionic material;
a working electrode and a counter electrode respectively disposed on the front surface and rear surface of the filter;
a potentiostat configured to apply a voltage of a second polarity, opposite to the first polarity, to the working electrode, and to measure current output from the working electrode over a predetermined period of time; and
a controller configured to:
calculate a maximum value of the current obtained during the predetermined period of time, based on the current measured by the potentiostat,
calculate a value of the voltage applied by the potentiostat at a point in time corresponding to the maximum value of the current,
calculate the type and concentration of the ionic material from the voltage value, and
compare the type and concentration of the ionic material with one or more reference values to determine whether the filter is contaminated,
wherein the potentiostat is configured to increase the voltage applied to the working electrode for the predetermined period of time.
9. The filter assembly of claim 8 , wherein the working electrode includes a first electrode body and a first connection, the first connection electrically connecting the first electrode body to the housing, and
wherein the counter electrode includes a second electrode body and a second connection, the second connection electrically connecting the second electrode body to the housing.
10. The filter assembly of claim 9 , wherein the first electrode body and the second electrode body have similar sizes.
11. The filter assembly of claim 9 , wherein the first electrode body and the second electrode body are made of the same material as each other.
12. The filter assembly of claim 9 , wherein the first electrode body contacts the front surface of the filter, and wherein the second electrode body contacts the rear surface of the filter.
13. The filter assembly of claim 12 , further comprising a reference electrode disposed adjacent to the counter electrode and connected to the potentiostat.
14. The filter assembly of claim 8 , wherein the filter comprises a plurality of filter layers arranged along a longwise direction of the housing, the working electrode comprises a plurality of working electrodes, and the counter electrode comprises a plurality of counter electrodes, and
wherein working electrodes of the plurality of working electrodes are disposed alternately with counter electrodes of the plurality of counter electrodes within gaps between filter layers of the plurality of filter layers.
15. A filter contamination measuring method comprising:
applying a voltage of a second polarity, opposite to a first polarity, to a working electrode disposed adjacent to a first surface of a filter, wherein the filter is configured to adsorb an ionic material of the first polarity;
increasing the voltage over a predetermined amount of time using a potentiostat, and measuring a resultant current output from the working electrode;
calculating a change curve of the current, which includes values of the current arranged over time;
detecting a peak in the change curve of the current, and calculating a maximum value of the current at the peak;
calculating a value of the voltage applied by the potentiostat at the detected maximum value of the current;
calculating a type of the ionic material adsorbed on the filter from the voltage value, and calculating a concentration of the ionic material adsorbed on the filter from the maximum value of the current; and
comparing the calculated concentration of the ionic material with one or more pre-stored reference values to determine whether the filter is contaminated.
16. The filter contamination measuring method of claim 15 , wherein the voltage of the second polarity is within a range of a first voltage to a second voltage, and includes an oxidation voltage value or a reduction voltage value of the ionic material.
17. The filter contamination measuring method of claim 15 , wherein the calculating of the type of the ionic material further includes comparing the voltage value with an oxidation voltage value or a reduction voltage value of the ionic material.
18. The filter contamination measuring method of claim 15 , wherein the filter is a membrane filter, and wherein the ionic material is adsorbed on a pore of the membrane filter.
19. The filter contamination measuring method of claim 18 , wherein the ionic material adsorbed on the pore is detached from the filter when the voltage of the second polarity is applied to the membrane filter.
20. The filter contamination measuring method of claim 15 , wherein the ionic material includes a positive ion, and wherein the voltage of the second polarity is a negative voltage.