Salinity measuring apparatus

摘要

A salinity measuring apparatus to determine salinity of food includes a salinity sensing unit including a pair of measuring electrodes and a capacitor, a switching unit to switch a voltage of the capacitor of the salinity sensing unit, and a control unit to provide a pulse signal with a constant frequency to the switching unit and to determine the salinity of the food which is in contact with the measuring electrodes of the salinity sensing unit based on when the voltage of the capacitor reaches a reference voltage. By providing the pulse signal with the constant frequency to the switching unit, it is possible to minimize the internal impedance variation of the capacitor and to more accurately measure the salinity of the food. Since a period when the voltage of the capacitor is substantially “0” is present, it is possible to minimize accumulation of ions in the measuring electrodes.

主权项

1. A salinity measuring apparatus to determine salinity of food, the salinity measuring apparatus comprising:
a salinity sensing unit including a pair of measuring electrodes, a capacitor, and a resistor, the resistor being connected between the measuring electrodes in parallel; a switching unit to switch a voltage of the capacitor of the salinity sensing unit; and a control unit to provide a pulse signal with a constant frequency to the switching unit and to determine the salinity of the food which is in contact with the measuring electrodes of the salinity sensing unit based on a time when the voltage of the capacitor reaches a reference voltage, wherein the period of the pulse signal includes a period when the voltage of the capacitor is substantially 0 when the capacitor is discharged.