The Measured Spectra window connects your design to the spectrophotometer. Import a measured reflectance, transmittance, or absorptance curve from an instrument file and overlay it on Optical Evaluation to compare prediction against measurement; export either the computed design spectrum or your imported curves to a portable file. The window is split into Import and Export tabs.

Settings

Import

Two file families are supported:

• Generic CSV / TXT / ASCII (.csv, .txt, .asc) — plain λ, value tables. The delimiter (comma, semicolon, tab, or whitespace), header rows, and decimal-comma locale are detected automatically.
• JCAMP-DX (.dx, .jdx) — the self-describing IUPAC spectroscopy standard. It carries its own units and quantity, so it imports directly. Compound LINK files import every block.

For a generic table you confirm the parse before adding it:

• Delimiter / column — which column is the wavelength and which is the value.
• X unit — nm, µm, or cm⁻¹ (auto-detected; override if wrong).
• Quantity — T, R, or A.
• Y scale — percent or fraction; absorbance is converted to transmittance.
• Preview — a small plot of the parsed curve before you commit.

Imported curves are stored on the design and persist with the project. On Optical Evaluation they appear as dotted lines with open-circle markers, colored by R / T / A. Show, hide, or remove them from the Import tab.

Export

A “What to export” chooser picks the source:

• Design spectrum — the computed T / R / A of the active design. Set the wavelength start / end / step, an angle-of-incidence list, the channels (T / R / A), and s / p (absorptance has no s/p split). It honors the active surface mode (front / back / total) and works without Optical Evaluation open.
• Measured curves — re-export the overlays you imported.

A Format toggle writes either CSV or JCAMP-DX for either source.

How to read it

The typical use is validating a deposition run: import the spectrophotometer trace and compare it directly against the predicted design curve on Optical Evaluation. Where the measured and computed curves diverge tells you how the as-built coating departs from the design. For an instrument that isn’t directly supported, export a CSV from its own software — the generic table importer reads ordinary λ, value exports — and JCAMP-DX export makes a TFStudio curve loadable in any spectroscopy tool.

References

• McDonald & Wilks, Appl. Spectrosc. 42, 151 (1988) — the JCAMP-DX XYDATA / ASDF format (AFFN, PAC, SQZ, DIF, DUP).