Purpose – Since first small personal exposimeters became available, some studies have characterized personal exposition to radio frequency electromagnetic fields. The effect of body and relative position of the exposimeter have been also analyzed but some questions are still unanswered. The paper aims to discuss these issues. Design/methodology/approach – Using three personal exposimeters in four different subjects, the authors characterized and compared measurements in a controlled experiment. Findings – The authors found statistically significance differences between exposimeters and subjects due to relative position (right and left) and a control position far from the body (center). It should indicate that body and relative position of the exposimeter affect directly to the measurement, conditioning final and average results. Research limitations/implications – Measurements using personal exposimeters have to be reconsidered and controlled. Originality/value – The authors test personal exposimeters limitations in real conditions.

FRIDA (inFRared Imager and Dissector for the Adaptive optics system of the Gran Telescopio Canarias) is designed as a diffraction limited instrument that will offer broad and narrow band imaging and integral field spectroscopy capabilities with low (R ~ 1,500), intermediate (R ~ 4,500) and high (R ~ 30,000) spectral resolutions to operate in the wavelength range 0.9 -2.5 m. The integral field unit is based on a monolithic image slicer. The imaging and IFS observing modes will use the same Teledyne 2K x 2K detector. FRIDA will be based at the Nasmyth B platform of GTC, behind the AO system. The key scientific objectives of the instrument include studies of solar system bodies, low mass objects, circumstellar outflow phenomena in advanced stages of stellar evolution, active galactic nuclei, high redshift galaxies, resolved stellar populations, semi-detached binary systems, young stellar objects and star forming environments. FRIDA is a collaborative project between the main GTC partners, namely, Spain, México and Florida. In this paper, we present the status of the instrument design as it is currently being prepared for its manufacture, after an intensive prototypes' phase and design optimization. The CDR was held in September 2011.