ISE-8 · Solid State · Replacement Chip Series
8-Ion Multi-Sensor
Measurement System
Simultaneous solid-state potentiometric measurement of eight major ionic species in a single pass. Nernstian response across monovalent and divalent ions, calibrated with application-specific multi-ion solution series. Replacement ISE chips available for all sensor positions.
Ions measured
8
Simultaneous
Accuracy
±5%
vs. traceable stds
Max range
10,000
ppm (NO₃⁻)
Ion response characteristics
Ca²⁺
Calcium
+29 mV/dec0.5 – 5,000 ppm
K⁺
Potassium
+59 mV/dec0.5 – 5,000 ppm
Mg²⁺
Magnesium
+29 mV/dec0.5 – 5,000 ppm
Na⁺
Sodium
+59 mV/dec0.5 – 5,000 ppm
NH₄⁺
Ammonium
+59 mV/dec0.5 – 5,000 ppm
Cl⁻
Chloride
−59 mV/dec0.5 – 5,000 ppm
NO₃⁻
Nitrate
−59 mV/dec0.5 – 10,000 ppm
HPO₄²⁻
Phosphate
−30 mV/dec0.5 – 5,000 ppm
Application-optimised measurement windows
While each sensor is capable of measuring across its full range (0.5 – 5,000 ppm; 10,000 ppm for NO₃⁻), the relevant concentration window in practice is set by the chemistry of the application. Each system is supplied with calibration solutions matched to that window — so the sensor is always operating in its most accurate, best-resolved region for the specific environment being monitored.
Accuracy
vs. traceable standards
±5%
Measured against certified single- and multi-ion reference solutions under controlled laboratory conditions.
Side-by-side vs. laboratory
±10%
Typical agreement in direct parallel comparisons with independent laboratory analysis of identical samples.
Note: conventional wet-chemistry laboratory methods carry their own significant variability — sample handling, digestion, matrix effects, and instrument calibration all contribute error. A ±10% agreement in side-by-side testing therefore represents strong real-world performance.
Application-specific calibration ranges (ppm)
| Ion |
Cal. Solution 1 (low) |
Cal. Solution 2 (×10) |
Cal. Solution 3 (×20) |
Working range |
Calibration methodology
Multi-ion solution series
Each application ships with a matched 3-point calibration set. Solutions span a decade of concentration (Sol. 1 → Sol. 2, 10× step) ensuring robust Nernstian slope determination and R² ≥ 0.999.
Simultaneous calibration
All 6–8 sensors are calibrated in a single immersion sequence, eliminating inter-session drift. Application-specific solution compositions reflect realistic ion ratios for the target matrix.
Nernstian response
Monovalent ions (K⁺, Na⁺, NH₄⁺, Cl⁻, NO₃⁻): ±59 mV/decade. Divalent ions (Ca²⁺, Mg²⁺): +29 mV/decade. Phosphate exhibits anomalous response: −30 mV/decade.
Solid-state construction
No internal reference solution or liquid junction required. Robust to field conditions, compatible with flow-through and immersion deployment. Electronics developed in partnership with Zealquest (China).
