Calibration of FTIR

As per USP, criteria for FTIR calibration to check Resolution?

Resolving Power (Resolution)
The following specification for resolving power is given in supplement 1 to the fourteenth edition of the Japanese Pharmacopoeia and in EP 4.0.
The respective differences in transmittance are measured and if they both are no less than the criteria values then system performance regarding this item is judged to be satisfactory.

When the spectrum of a polystyrene film about 0.04 mm thick is recorded, the depth of the trough from the maximum absorption at about 2850 cm-1 to the minimum at about 2870 cm-1 should be not less than 18% transmittance and that from the maximum at about 1583 cm-1 to the minimum at about 1589 cm-1 should not be less than 12% transmittance.

Pharmacopoeia of the United States of America (USP)
FTIR is mentioned in the Pharmacopoeia of the United States of America (USP). As shown below, however, it tells the reader to refer to manufacturers instruction manuals for detailed instructions. Detailed instructions for operating spectrophotometers are
supplied by manufacturers.
To achieve significant and valid results, the operator of a spectrophotometer should be aware of its limitation and of potential sources of error and variation. The instruction manual should be followed closely on such matters as care, cleaning, and calibration of the