It has been brought to our attention that facilities have been sold scanning densitometers with steps for mid-density (MD) and density difference (DD) preset by the manufacturer, and the manufacturer's representative has not explained to the facility staff that they should reset the MD and DD to reflect the facility’s actual conditions. While reviewing the QC records during an inspection, the fact that the facility is using other than their own MD and DD values may not be obvious at first glance. Problems with facility's daily QC processor charting, however, will probably result and you should be aware that this may be the cause.
There is not a question in the inspection procedures regarding the particular MD and DD values which the facility is using. If, during an inspection, you determine that the MD and DD values were not set correctly and you assist the facility in correcting this, please note this information in the REMARKS Section that prints out to the facility. By using this REMARKS section, the facility will be aware that this is a significant problem, which was discussed during the inspection, and needs to be remedied.