The MICROSPEC X-Ray Probe was developed to perform spectral and dose-equivalent measurements for low-energy photons for assessment of radiological hazards for the skin Hp(0.07) and eye Hp(3). The measurement of low-energy photons is often complicated by the presence of high-energy gamma rays that produce counts in the low-energy regions, which interferes with the counting of X-rays and low-energy gamma rays.  The MICROSPEC X-Ray Probe minimizes this problem by using a thin NaI crystal, which has low detection efficiency for high-energy gamma rays and high detection efficiency for low-energy gamma rays.

The X-Ray Probe is designed to detect photons from less than 5 keV, to cover ⁵⁵Fe x-rays at 5.9 keV, up to over 200 keV.  over this region, high-energy gamma monitors can significantly underestimate radiological hazards since Hp(0.07) and HP(3) can be much larger than Hp(10) or H*(10).  The X-Ray Probe provides accurate measurements of Hp(0.07) and Hp(3) for radiation fields that contain low-energy photon hazards.  Such hazards are encountered particularly in diagnostic or interventional radiology involving X-ray tubes operating up to 150 keV.  The monitoring of ⁵⁵Fe has also been found to be very important for detection of contamination inside iron pipes involved in reactor maintenance or decommissioning operations.