New Hampshire Code of Administrative Rules
He - Department of Health and Human Services
Subtitle He-P - Former Division of Public Health Services
Chapter He-P 4000 - NEW HAMPSHIRE RULES FOR THE CONTROL OF RADIATION
Part He-P 4046 - USE OF RADIATION MACHINES: GENERAL REQUIREMENTS FOR ALL DIAGNOSTIC AND VETERINARY X-RAY SYSTEMS
Section He-P 4046.04 - Fluoroscopic X-ray Systems - Barrier Transmitted Radiation Rate Limits

(a) The exposure rate due to transmission through the primary protective barrier with the attenuation block in the useful beam, combined with radiation from the image intensifier, if provided, shall not exceed 2 milliroentgens per hour at 10 centimeters from any accessible surface of the fluoroscopic imaging assembly beyond the plane of the image receptor per roentgen per minute of entrance exposure rate.

(b) The exposure rate due to transmission through the primary protective barrier combined with radiation from the image intensifier shall be determined by measurements averaged over an area of 100 square centimeters.

(c) If the source is below the tabletop, measurements shall be made with the input surface of the fluoroscopic imaging assembly positioned 30 centimeters above the tabletop.

(d) If the source is above the tabletop and the SID is variable, the measurement shall be made with the end of the beam-limiting device or spacer as close to the tabletop as it can be placed, but no closer than 30 centimeters.

(e) Movable grids and compression devices shall be removed from the useful beam during the measurement.