THIN-FILM WINDOW SELECTION GUIDE
As a guide, the adjacent chart relates % Transmittance through a thin-film substance vs. analyte-line energy, KeV, and Wavelength, in Angstrom units.
- Select the analyte-line of interest in either KeV or Angstrom units
- At the point of extrapolated intersection of each curve, read the % Transmittance. The greater the % Transmittance value the lower the absorption will be. This may be translated into other factors such as lower elemental detection limits and shorter integration times.
- Select the thin-film substance with the highest % Transmittance value.
- Consider the Degradation Resistanceassignments to the thin film sample support substance for the sample types to be analyzed.
Degradation Resistance Of Thin-film Substances
| CHEMICAL | MYLAR or HOSTAPHAN | POLY- CARBONATE | Etnom-S | POLY- PROPYLENE | POLY- IMIDE | PROLENE | ULTRA- POLYESTER |
| Acid, dilute or weak | G | G | G | E | N | G | G |
| Acids, conc. | G | G | G | E | N | E | G |
| Alcohols, aliphatic | N | G | G | E | G | E | N |
| Aldehydes | U | F | F | E | E | E | U |
| Alkalies, conc. | N | N | G | E | E | E | N |
| Esters | N | N | F | G | G | G | N |
| Ethers | F | N | F | N | U | N | F |
| Hydrocarbon, aliphatic | G | N | E | G | E | G | G |
| Hydrocarbon, aromatic | N | N | E | N | E | N | N |
| Hydrocarbon, halogenated | F | N | F | N | F | N | F |
| Ketones | N | N | G | G | G | G | N |
| Oxidizing agents | F | N | F | F | N | F | F |
E=Excellent, G=Good, F=Fair, N=Not recommended, U=Unknown
Shaded columns represent thin-film window materials determined “Unsuitable for analyzing sulfur in diesel fuel, gasoline and other petroleum products containing aromatic hydrocarbons,” ASTM D-4294-03 and ASTM D-6445-99 (2004), in addition to other testing procedures.
IMPORTANT: The degradation resistance of thin-films contained in the above illustration is provided as a matter of information purposes only and is not intended to preclude actual testing and suitability of use and applications. The responsibility of acceptance and safety resides totally with the user.