Gas sensor module, refrigerator having the same and control method for the refrigerator
A gas sensor module, a refrigerator having the same and a control method for the refrigerator. In another aspect, in a gas sensor module, ion pairs are pre-dissolved in an aqueous solution while the amount thereof and pH of an initial aqueous solution may be adjusted to adjust a sensing range and sensitivity with respect to a target gas to be sensed. In another aspect, the gas sensor module senses the amount of target gas includes an aqueous solution in which ion pairs of a substance having the same dissociation constant as the target gas are dissolved, and senses a pH change of the aqueous solution that occurs due to the target gas being dissolved in the aqueous solution.
1. A gas sensor module configured to sense a concentration of a target gas, the gas sensor module comprising:
an aqueous solution in which ion pairs of a substance having a substantially same dissociation constant as that of the target gas are dissolved,
wherein the gas sensor module is configured to sense a pH change of the aqueous solution that occurs due to the target gas being dissolved in the aqueous solution to indicate the concentration of the target gas, and
wherein the aqueous solution is mixed with a pH indicator, which changes in color in accordance with the pH change of the aqueous solution.
2. The gas sensor module according to claim 1 , wherein the target gas is a volatile organic acid or ammonia.
3. The gas sensor module according to claim 1 , wherein a resolution of the gas sensor module varies in accordance with a concentration of the ion pairs dissolved in the aqueous solution.
4. The gas sensor module according to claim 1 , wherein a sensing range of the gas sensor module with respect to the concentration of the target gas varies in accordance with an initial pH of the aqueous solution.
5. The gas sensor module according to claim 1 , further comprising an electrochemical sensor configured to sense the pH change,
wherein the electrochemical sensor comprises:
a working electrode, a potential of which varies in accordance with the pH change within the aqueous solution; and
a reference electrode to serve as a reference for the working electrode.
6. The gas sensor module according to claim 1 , wherein
the target gas is a carboxylic acid, and
the pH indicator is at least one selected from 0.001 wt% to 0.1 wt% of bromothymol blue and 0.001 wt% to 0.1 wt% of methyl red.
7. The gas sensor module according to claim 1 , wherein,
the target gas is ammonia, and
the pH indicator is at least one selected from 0.001 wt% to 0.1 wt% of a thymol blue reagent, 0.001 wt% to 0.1 wt% of cresol red, and 0.001 wt% to 0.1 wt% of a phenolphthalein reagent.
8. The gas sensor module according to claim 1 , further comprising:
a housing configured to accommodate the aqueous solution and having an inlet into which the target gas is introduced; and
a porous membrane through which the target gas, having introduced into the inlet, permeates to dissolve into the aqueous solution.
9. An electronic product comprising the gas sensor module of claim 1 .
10. The electronic product according to claim 9 , wherein to indicate the concentration of the target gas, the gas sensor module generates a signal output based on the pH change, and the electronic product further comprises:
a signal reception unit configured to receive the signal output from the gas sensor module; and
a control unit configured to determine a state of target food based on the received signal output.
11. The electronic product according to claim 9 , wherein the electronic product is a gas sensor assembly attachable to and detachable from at least one of a storage compartment and a storage container of a refrigerator, and further comprises:
a control unit configured to determine a state of target food based on a signal output from the gas sensor module; and
a communication unit configured to communicate the determined state of the target food to the refrigerator.
12. An electronic product comprising the gas sensor module of claim 6 .
13. The electronic product according to claim 12 , further comprising:
an optical sensor configured to detect a color of the gas sensor module, and
a control unit configured to determine a state of target food based on the color detected by the optical sensor.
14. The electronic product according to claim 13 , further comprising the display unit configured to display the determined state of the target food.
15. A control method comprising:
using an aqueous solution, in which ion pairs of a substance having a substantially same dissociation constant as that of a target gas are dissolved, and a gas sensor module, which is configured to sense a pH change of the aqueous solution that occurs due to the target gas being dissolved in the aqueous solution and indicate the pH change by producing at least one of a signal generated based on the pH change and a color change in accordance with the pH change, to sense the pH change in response to the target gas being dissolved in the aqueous solution;
determining the concentration of the target gas based on the at least one of the signal generated based on the pH change and the color change of the gas sensor module in accordance with the pH change; and
determining a state of target food based on the determined concentration of the target gas.
16. The control method according to claim 15 , further comprising displaying the determined state of the target food.
17. The control method according to claim 15 , wherein:
the electronic product is a refrigerator; and
the control method for the electronic product further comprises controlling a temperature of the refrigerator based on the determined state of the target food.
18. The control method according to claim 17 , wherein:
the control method further comprises receiving an input of a desired state of target food after determining the state of the target food; and
the controlling of the temperature of the refrigerator includes controlling the temperature of the refrigerator based on the determined state of the target food and the input desired state of the target food.
19. The control method according to claim 17 , wherein:
the at least one of the signal and the color change is the signal;
the control method further comprises receiving an input of a desired state of target food before receiving the signal from the gas sensor module; and
the controlling of the temperature of the refrigerator includes controlling the temperature of the refrigerator based on the determined state of the target food and the input desired state of the target food.