The WafIR™ is a horizontal ATR accessory for analysis of monolayers and other thin coatings applied to one side of double-side polished wafers. It features a 45° incident angle Si crystal to couple the light in and out of the wafers. The WafIR incorporates a pressure applicator with pressure pads designed for optimal contact with minimal contact area and the contact area is outside the measured area. The pressure applicator includes a slip-clutch to limit the total force applied to the sample and is compatible with a torque wrench for repeatability. The WafIR is fully enclosed for rapid purging and is compatible with most FTIR spectrometers.