Simple solutions for spectra acquisition in the MIR range have been studied in order to develop analysis systems for various process control and safety applications. The detection unit is a 64-pixel linear detector (μray 64, IR Microsystems), based on pyroelectric thin film technology. This detector exhibits a high signal to noise ratio at room temperature and therefore is ideal for the production of rugged, low cost and simple to use mini-spectrometers. We combined various technologies, including dispersive optics (gratings) and linear variable filters (LVF), with the μray 64 detector to build small spectral engines. These devices have been tested and their characteristics will be discussed in terms of sensitivity, resolution and costs.