Ca2+ Hardness In Water Calcium Ion Selective Electrode ISE Sensor Reagent Free

Ca2+ Hardness in Water Calcium Ion Electrode ISE Sensor

>>Technical Parameter

Concentration Range: 1M to 5×10⁻⁶ M

(40,000 ppm to 0.02 ppm)

pH Range: 2.5–11 pH

Temperature Range: 0–50°C

Pressure Resistance: Not pressure resistant

Temperature Sensors: NTC10K/NTC2.2K/PT100/PT1000

Housing Material: PP

Membrane Resistance: 1–4 MΩ

Connection Thread: NPT 3/4"

Cable Length: 10m or as agreed

Cable Connector: Pin, BNC, or as agreed

>>Overview

The ion-selective electrode (ISE), also known as a membrane electrode, is an electrode with a sensitive membrane that generates a membrane potential based on ion exchange or diffusion. It primarily consists of an ion-selective membrane, an internal reference electrode (typically Ag/AgCl), and an internal reference solution (composed of chloride and strong electrolyte solutions of the target ion). The ISE measures the electrical potential of a specific ion in a solution, which is determined relative to a reference electrode with a constant potential. The potential difference between the two electrodes depends on the activity of the specific ion in the solution. This activity is related to the ion’s concentration, enabling quantitative analysis.

>>Feature

• Reagent-free, pollution-free, cost-effective, and eco-friendly.‌
• Redox potential measurement method ensures fast response time and stable signals.‌
• Electrode made of PP (polypropylene) material.‌
• High-quality sensor-specific cables enhance signal accuracy and stability.

>>Pre-Measurement Preparation‌

1. Remove the protective cap from the electrode tip. ‌Note:‌ Avoid touching the sensitive area with fingers.
2. Shake the electrode downward (like a thermometer) to remove internal air bubbles.
3. For new or long-unused electrodes, perform activation by soaking in ‌1 ppm standard solution for at least 24 hours‌.
4. 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)

1. Connect the electrode to the meter.

2. Pour ‌100 mL of deionized water‌ into a ‌150 mL beaker‌ and stir thoroughly. Set the meter to ‌mV mode‌.

3. Blot the rinsed electrode dry and immerse it in the prepared deionized water.

4. Add ‌1 mL of 1000 ppm standard solution‌ to the beaker, stir thoroughly, and record the stable reading (‌E₁‌).

5. Add ‌10 mL of the same standard solution‌ to the beaker, stir thoroughly, and record the stable reading (‌E₂‌).

6. 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:

1. Prepare freshly diluted standard solution (lowest concentration).
2. Soak the electrode in the diluted solution for ‌10 minutes‌ before testing.
3. Repeat the calibration steps.
   If the issue persists, contact the manufacturer’s technical support or replace the electrode.

>>Storage

1. ‌Short-term storage:‌ Preserve the electrode in deionized water or low-concentration standard solution (1 ppm). No reactivation is required before reuse.
2. ‌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.