Some of the sample holders available. Transmission sample holders for (a) a pellet and (b) a powder with 1 mm sample thickness. (c), (d) The fluorescence sample holder from two different perspectives. Red arrows indicate the X-ray path, both incoming and outgoing. All holders have a grid at the bottom to hold the sample and allow the gases to go through it. The sample (powder) must be packed as compact as possible, graining it before positioning and leaving a nice flat surface to improve recording of IR spectra.