Non-Intrusive Reflective pH Sensors
Ocean Optics’ new non-intrusive reflective pH technology comes as the next evolution of our pH sensing product line. Previous pH sensor products have been based on colorimetric transmissive measurements, and have therefore fallen susceptible to ambient light interferences and sample color or turbidity effects.
Our new approach uses electroformed mesh to metallize the pH sensor material, providing an optically reflective yet ion permeable membrane between the sensor and the environment.
The electroforming process creates highly precise mesh sheets through atom-by-atom electrodeposition in a plating bath. The hole and wire sizes that can be achieved are on the order of a few microns, with sub-micron repeatability.
This novel technique is ideal for our colorimetric sensor applications.
This new form factor allows for non-intrusive pH measurement through the optically clear wall of a container using one of several available reflection probes. The patches are self-adhesive, and will firmly hold to both glass and plastic during long-term exposure in aqueous environments. A schematic is shown below of how the multi-layer patches are assembled.
Typical Applications
Specifications
pH Range: |
5 - 9 |
Temperature Range: |
-6 - 60 °C |
Analytical Wavelength: |
617 nm |
Baseline Correction Wavelengths: |
509 nm (isosbestic) or 800 nm |
User Calibration Accuracy: |
Up to 2% of reading |
Factory Reset Accuracy: |
0% at reset point 1% within 1 pH unit of reset Up to 4% at 3 pH units from reset |
Resolution: |
~0.03 pH unit in most cases |
Response Time (t90): |
30 seconds |
Calibration Requirements (minimum): |
Factory Calibration: 3 buffers User Calibration: 5 or 6 buffers |
Sterilization: |
Gamma, EtO |
Acceptable Probes: |
3-Around-1 Angled RE-CIFBORO R200/400/600-7 |
Setup
- USB4000-FL
- Light Source (350-1000 nm)
- Probes (R1000-4- Reflection Probes)
- pH Patches (PH-BCG-REFLECT) pack of 5
Sample Spectra
Demonstration of color immunity of reflective patch
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