A spectrophotometer comprising a housing containing a light source, a first light transmitting connection between the housing and a probe for transmitting light from the light source to a sample to be analysed, a second light transmitting connection between the housing and the probe for receiving light from the sample to be analysed, and, within the housing, optical components comprising means for directing the received light to means arranged to produce a spectrum of different wavelengths distributed spatially, and at least one photodetector for detecting light in the spectrum, wherein the optical components are mounted rigidly to a chassis which is mounted within the housing by means for at least partially absorbing shock and/or vibrations.