DHS 157.76(12)(12) Air kerma measurements. Annual measurements of both typical and maximum air kerma shall be made by a medical physicist or a person approved by a medical physicist.

DHS 157.76 NoteNote: Materials should be placed in the useful beam to protect the imaging system when conducting these periodic measurements. Air kerma measurements do not include backscatter.

DHS 157.76 HistoryHistory: CR 01-108: cr. Register July 2002 No. 559, eff. 8-1-02; CR 06-021: r. and recr. Register October 2006 No. 610, eff. 11-1-06; CR 09-062: cr. (11) and (12) Register April 2010 No. 652, eff. 5-1-10; CR 16-078: r. and recr. (7) (c), cr. (7) (d), am. (11) (a) Register January 2018 No. 745, eff. 2-1-18; correction in (7) (c) 2. made under s. 35.17, Stats., Register January 2018 No. 745; CR 22-015: am. (intro.), (2) (b), (8) Register June 2023 No. 810, eff. 7-1-23.

DHS 157.77(1)(a)(a) Collimation. The useful beam shall be limited to the area of clinical interest. This requirement is met if a positive beam-limiting device meeting manufacturer’s specifications has been properly used or if evidence of collimation is shown on at least 3 sides or 3 corners of the film. Mammography systems are exempt from the collimation requirement.

DHS 157.77(1)(b)(b) General purpose stationary and mobile x-ray systems. General purpose stationary and mobile x-ray systems, including veterinary systems other than portable, shall meet both of the following requirements:

DHS 157.77(1)(b)1.1. Only x-ray systems provided with means for independent stepless adjustment of at least 2 dimensions of the x-ray field may be used.

DHS 157.77(1)(b)2.2. A method shall be provided for visually defining the perimeter of the x-ray field. The total misalignment of the edges of the visually defined field with the respective edges of the x-ray field along either the length or width of the visually defined field may not exceed 2% of the distance from the source to the center of the visually defined field when the surface upon which it appears is perpendicular to the axis of the x-ray beam.

DHS 157.77(1)(c)(c) Stationary general purpose x-ray systems. Stationary general purpose x-ray systems, both certified and non-certified, shall meet all the following requirements:

DHS 157.77(1)(c)1.1. A method shall be provided to indicate when the axis of the x-ray beam is perpendicular to the plane of the image receptor, to align the center of the x-ray field with respect to the center of the image receptor to within 2% of the SID and to indicate the SID to within 2%.

DHS 157.77(1)(c)2.2. The beam-limiting device shall indicate numerically the field size in the plane of the image receptor to which it is adjusted.

DHS 157.77(1)(c)3.3. Field size dimensions and SIDs shall be specified in inches or centimeters and shall ensure that aperture adjustments result in x-ray field dimensions in the plane of the image receptor that correspond to those indicated by the beam-limiting device to within 2% of the SID when the beam axis is indicated to be perpendicular to the plane of the image receptor.

DHS 157.77(1)(d)(d) X-ray systems designed for one image receptor size. Radiographic equipment designed for only one image receptor size at a fixed SID shall be provided with means to limit the field at the plane of the image receptor to dimensions no greater than those of the image receptor, and to align the center of the x-ray field with the center of the image receptor to within 2% of the SID, or shall be provided with means to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor.

DHS 157.77(1)(e)(e) Miscellaneous and veterinary x-ray systems. X-ray systems other than those described in pars. (a) to (c), veterinary systems installed prior to the effective date of August 1, 2002, and all portable veterinary x-ray systems shall meet all of the following requirements:

DHS 157.77(1)(e)1.1. Means shall be provided to limit the x-ray field in the plane of the image receptor so that such field does not exceed each dimension of the image receptor by more than 2% of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor.

DHS 157.77(1)(e)2.2. Means shall be provided to align the center of the x-ray field with the center of the image receptor to within 2% of the SID, or means shall be provided to both size and align the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor. Compliance shall be determined with the axis of the x-ray beam perpendicular to the plane of the image receptor.

DHS 157.77(1)(e)3.3. The requirements in subds. 1. and 2. may be met with a collimator system that meets the requirements for a general purpose x-ray system or, when alignment means are also provided, may be met with either of the following:

DHS 157.77(1)(e)3.a.a. An assortment of removable, fixed-aperture, beam-limiting devices sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is designed with each such device having clear and permanent markings to indicate the image receptor size and SID for which it is designed.

DHS 157.77(1)(e)3.b.b. A beam-limiting device with multiple fixed apertures sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is designed. Permanent, clearly legible markings shall indicate the image receptor size and SID that each aperture is designed for and shall indicate which aperture is in position for use.