| 1 | Spectral Coverage | Mid-infrared coverage of approximately 4,000–400 cm-1 for routine organic and inorganic analysis. | Review the published optical specification and inspect a certified polystyrene film spectrum. | 15% | A broad mid-IR range supports identification of functional groups and comparison with spectral libraries. |
| 2 | Spectral Resolution | Selectable resolution down to 2–4 cm-1 is generally suitable for routine material identification. | Confirm the resolution setting, peak separation capability, and performance using a reference standard. | 12% | Higher resolution can help distinguish nearby absorption bands and improve qualitative interpretation. |
| 3 | Signal-to-Noise Performance | The supplier should state the measurement conditions, scan number, spectral resolution, and noise calculation used for its SNR claim. | Request raw spectra, test conditions, and an on-site or remote demonstration with a known sample. | 14% | Low noise improves the detection of weak bands and increases confidence in routine comparisons. |
| 4 | Measurement Accessories | Compatibility with ATR, transmission, diffuse-reflectance, and liquid-cell measurements is preferred for multi-purpose laboratories. | Check the supplied accessory list, crystal material, sample-size requirements, and replacement cost. | 12% | Flexible sampling reduces preparation time and allows analysis of solids, liquids, powders, films, and coatings. |
| 5 | Wavenumber Accuracy and Stability | The instrument should provide repeatable peak positions and include a documented verification or calibration procedure. | Use polystyrene or another traceable reference material to check peak-position repeatability. | 10% | Stable wavenumber performance is essential for library matching and batch-to-batch comparison. |
| 6 | Software and Data Integrity | Software should support background correction, baseline adjustment, spectral subtraction, library search, export, audit trails, and user access control where required. | Request a software demonstration and verify export formats, backup options, and electronic-record controls. | 12% | Good software improves reproducibility, reporting efficiency, traceability, and laboratory workflow integration. |
| 7 | Quality and Compliance Documentation | Availability of user manuals, factory test reports, electrical safety records, calibration procedures, and quality-system documentation. | Review the technical file and confirm whether documentation supports the intended regulated or research application. | 10% | Documented quality controls simplify installation qualification, method validation, and laboratory audits. |
| 8 | Application Method Support | Availability of validated or well-documented methods for polymers, pharmaceuticals, food, chemicals, minerals, and environmental samples. | Ask for application notes, sample-preparation protocols, reference spectra, and method-development assistance. | 8% | Practical method support reduces training time and helps users obtain reliable results faster. |
| 9 | After-Sales Service and Spare Parts | Clear warranty terms, preventive-maintenance options, response-time commitments, training, and local availability of critical consumables. | Request service-level terms, maintenance schedules, training scope, and spare-part lead times in writing. | 4% | Responsive support reduces downtime and protects the long-term value of the instrument. |
| 10 | Total Cost of Ownership | Evaluate purchase price together with accessories, software licenses, calibration, maintenance, training, consumables, and expected service life. | Compare a multi-year ownership quotation using the same configuration and service assumptions. | 3% | A transparent lifecycle cost comparison prevents apparently low-cost equipment from becoming expensive to operate. |