(1) Open the Software

Open OPUS 7.5 >> Key in the password and click “OK”

Check the instrument status, which can be found at the right bottom: Green means everything is good; Red means at least one test has failed, or hardware has a problem; Grey means there is no connection between PC and instrument.

(2) Load the program file

If no error is found, you can start the FTIR measurement by clicking the “Advanced measurement” button. Only amend the "Basic" and "Advanced" Tab.

Load the FTIR program file. There are two modes:

1. Transmission

2. Attenuated Total Reflection (ATR)

Choose either “MIR-FTIR ATR.xpm” or “MIR-FTIR Trans.xpm”.

(3) Key in the parameters

Under the "Advanced" tab, you can customize the parameters according to your experiment. The scan range from 4000cm^-1 to 400cm^-1 is for the mid-IR range. The typical parameters for FTIR:

Resolution: 4 cm^-1

Sample scan time: 32 Scans

Background scan time: 32 Scans

Save data from: 4000 cm^-1 to 400 cm^-1

(4) Load your samples

Put your sample on the small window. You should ensure the ART crystal is clean first.

Press the sample against the Attenuated total reflectance (ATR) crystal surface; do not exceed the factory-set contact pressure limit value, for example with additional manual force.

Note that liquid samples and pastes do not need to be pressed onto the ATR crystal. Only solid samples need to be pressed on the ATR crystal by using an integrated pressure application device.

(5) Start the FTIR measurement

A background spectrum is acquired and served as the reference of the FTIR signals. Background: Ambient water (about 3600 cm^–1 and about 1600 cm^–1 ) and carbon dioxide (about 2360 cm^–1 and sharp spike at 667 cm^–1 )

For transmission measurement, an empty beam pathway is used for the background measurement. Or blank KBr pellet is used as the background. In the case of a liquid cell, do not use an empty cell as background, which will generate fringe features in your spectrum.

Go back to the "Basic" Tab. Click “Background Single Channel” The Background spectrum will be saved in the instrument and served as the reference automatically.

After that, start the FTIR measurement by clicking "Background Single Channel" >> Start Measurement