This calcium ion-selective electrode (ISE) sensor measures Ca²⁺ hardness in water through membrane potential technology. The electrode features an ion-selective membrane, internal Ag/AgCl reference electrode, and internal reference solution. It determines ion activity relative to a reference electrode, enabling precise quantitative analysis of calcium ion concentration in aqueous solutions.

• Reagent-free operation eliminates chemical consumption and environmental pollution
• Redox potential measurement ensures fast response time and stable signal output
• Polypropylene housing provides chemical resistance and durability
• High-quality sensor cables enhance measurement accuracy and signal stability
• Cost-effective solution for continuous water quality monitoring

1. Remove protective cap from electrode tip
2. Shake electrode downward to remove internal air bubbles
3. For new or unused electrodes: activate by soaking in 1 ppm standard solution for 24 hours
4. Rinse with deionized water and blot dry with non-woven cloth
5. Before testing: immerse tip in deionized water for 5 minutes with stirring

1. Connect electrode to meter and set to mV mode
2. Pour 100 mL deionized water into 150 mL beaker with stirring
3. Blot electrode dry and immerse in prepared water
4. Add 1 mL of 1000 ppm standard solution, record stable reading (E₁)
5. Add 10 mL of same standard solution, record stable reading (E₂)
6. Calculate slope at 25°C as E₂ - E₁

• Short-term: Store in deionized water or 1 ppm standard solution
• Long-term: Rinse, dry thoroughly, and store in original packaging
• Reactivation required after long-term storage: soak in 1 mg/L standard solution for over 2 hours