Digital Potassium ion Sensor For Hydroponics
>>Overview
An electrochemical sensor that utilizes membrane potential to
determine the activity or concentration of ions in a solution. When
it comes into contact with a solution containing the target ions, a
membrane potential directly related to the ion activity is
generated at the interface between its sensing membrane and the
solution. The ion-selective electrode functions as a half-cell
(except for gas-sensing electrodes) and must be combined with an
appropriate reference electrode to form a complete electrochemical
cell. Under normal conditions, the potentials of the internal and
external reference electrodes, as well as the liquid junction
potential, remain constant. Any variation in the electromotive
force of the cell fully reflects changes in the membrane potential
of the ion-selective electrode, enabling its direct use as an
indicator electrode for potentiometric measurement of specific ion
activity in solutions. Key parameters characterizing the
fundamental properties of ion-selective electrodes include
selectivity, dynamic measurement range, response speed, accuracy,
stability, and lifespan. The sensing membrane of an ion-selective
electrode acts as a selectively permeable barrier, demonstrating
only relative selectivity towards different ions.
>>Feature
▪ Digital sensor with RS-485 output, MODBUS supported.
▪ Reagent-free operation, pollution-free, cost-effective, and
eco-friendly.
▪ Utilizes ion-selective method for faster response time and stable
signal.
▪ Electrode housing made of PP material, withstands temperatures
from 0°C to 50°C.
▪ Equipped with a dedicated high-quality four-core shielded cable
for accurate and stable signal transmission.
>>Technical Parameter
Power Supply: 9-36 VDC
Material: Main body: PP (Polypropylene); Cable: PVC
Waterproof Rating: IP68/NEMA 6P
Measurement Range: 0.1-1000 mg/L (expandable)
Temperature Range: 0-50°C
Accuracy: ±2.5% of measurement value; Temperature: ±0.5°C
Output: MODBUS RS485
Storage Temperature: 0-45°C
Pressure Range: ≤0.3 MPa
Calibration: Standard solution calibration, Comparative
calibration
Cable Length: Standard: 10 meters (extendable up to 100 meters)
>>Pre-Measurement Preparation
- Remove the protective cap from the electrode tip. Note: Avoid touching the sensitive area with fingers.
- Shake the electrode downward (like a thermometer) to remove
internal air bubbles.
- For new or long-unused electrodes, perform activation by soaking in
1 ppm standard solution for at least 24 hours.
- After activation, rinse the electrode with deionized water and
gently blot dry with a non-woven cloth or clean tissue. Before
testing, immerse the electrode tip in deionized water for 5 minutes with stirring. Replace the water multiple times and repeat
rinsing to prevent measurement errors.
>>Calibration (Slope Determination)
Connect the electrode to the meter.
Pour 100 mL of deionized water into a 150 mL beaker and stir thoroughly. Set the meter to mV mode.
Blot the rinsed electrode dry and immerse it in the prepared
deionized water.
Add 1 mL of 1000 ppm standard solution to the beaker, stir thoroughly, and record the stable reading (E₁).
Add 10 mL of the same standard solution to the beaker, stir thoroughly, and record the stable reading (E₂).
The slope at 25°C is calculated as E₂ – E₁. Compare the result with the specifications to validate electrode
performance.
>>Troubleshooting
If the slope deviates from the specified range:
- Prepare freshly diluted standard solution (lowest concentration).
- Soak the electrode in the diluted solution for 10 minutes before testing.
- Repeat the calibration steps.
If the issue persists, contact the manufacturer’s technical support
or replace the electrode.
>>Storage
- Short-term storage: Preserve the electrode in deionized water or low-concentration
standard solution (1 ppm). No reactivation is required before
reuse.
- Long-term storage: Rinse the electrode with deionized water, gently wipe the
membrane with a non-woven cloth, dry thoroughly, and store in its
original packaging. Reactivate in 1 mg/L standard solution, deionized water, or low-concentration
solution for over 2 hours before reuse.
