Standards – Liquid Absorbance and Reflectance
Proper analytical procedures require the use of standards or reference materials to ensure reliable results. If such monitoring shows the instrument is not performing according to its designed parameters, the instrument needs to be recalibrated to return it to optimum performance – i.e. its status when assembled and shipped from the factory.
Liquid Absorbance Standards
STAN-ABS absorbance standards are handy tools for verifying the photometric accuracy of your spectrometer setup. The standards are available in a kit format. Each kit comprises a background reference for low, medium and high absorbance solutions and is ready to use without additional solutions preparation. All standards are non-toxic and have a one-year shelf life.
| Standard | Spectral range, nm | NIST traceability |
| STAN-ABS-UV | 200-450 | Yes |
| STAN-ABS-VIS | 400-900 | Yes |
Reflectance Standards
Reflectance Standard
Ocean Insight offers specular and diffuse reflectance standards for measurements of various types of sample surfaces. Reflectance measurements are a ratio of the reflected light spectrum to the incident light spectrum. Since there is no way to directly collect all of the light incident on a surface, reflectivity is usually measured relative to a reference standard. To ensure best results, the standard selected should be similar in reflectivity to the sample to be measured.
| Standard | Diffuse/Specular | Material | Reflectivity vs Spectral range, nm | NIST traceability |
| STAN-SSH | Specular | Aluminium mirror on fused silica | ~87%-93% (200 – 1000 nm) ~93%-98% (1000 – 2500 nm) | No |
| STAN-SSH-NIST | Specular | Aluminium mirror on fused silica | ~87%-93% (200 – 1000 nm) ~93%-98% (1000 – 2500 nm) | Yes |
| STAN-SSL | Specular | Schott ND9 glass | ~5% (200 – 950 nm) ~4% (950-2500 nm) | No |
| WS-1 | Diffuse | PTFE | >98% (250-1500 nm)>95% (250-2200 nm) | No |
| WS-1-SL | Diffuse | Spectralon | 99% (400-1500 nm)>96% (250-2000 nm) | No |
