Resolution vs. throughput
Optical resolution is set by the grating groove density, slit width and focal length. Narrower slits and higher groove density improve resolution but reduce throughput. For absorption spectroscopy of solutions, 1–2 nm is usually ample; resolving laser lines demands 0.1 nm-class optics.
Sensitivity: cooling changes the game
A thermoelectrically cooled CCD (e.g. −15 °C on the HX-SP-Cooled) dramatically improves long-integration stability and low-light performance — roughly doubling the effective signal-to-noise ratio versus uncooled units. Check quantization noise and SNR specifications at comparable integration times, not just pixel counts.
Wavelength range
Wide single-shot range (e.g. 180–1100 nm) simplifies setups, but grating/detector physics imposes trade-offs at the extremes. If you only need 400–700 nm colorimetry, a narrower optimized range gives better throughput per nm.
Practical selection table
| Application | Priority | Recommended |
|---|---|---|
| UV-Vis absorbance | Range, stability | HX-SP-Cooled |
| LED binning / color | Speed, repeatability | HX-SP-Cooled + integrating sphere |
| Laser line profiling | Resolution | 0.1 nm-class optics |
| PL / quantum yield | Range + sensitivity | HX-QEY6500-PLS system |
Don't forget the accessories
Fibers, cosine correctors, cuvette holders and integrating spheres shape the measurement as much as the spectrometer itself. Ask for a complete signal-chain recommendation.