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.

DHS 157.77(2)(a)(a) Exposure initiation. Means shall be provided to initiate the radiation exposure by a deliberate action on the part of the operator, such as the depression of a switch. Radiation exposure may not be initiated without such an action. In addition, exposure may not be initiated when the timer is set to a “zero” or “off” position if either position is provided.

DHS 157.77(2)(b)(b) Exposure indication. Means shall be provided for visual indication observable at or from the operator’s protected position whenever x-rays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated.

DHS 157.77(2)(c)(c) Exposure termination. Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, a preset number of pulses or a preset radiation exposure to the image receptor. Except for dental panoramic systems, termination of an exposure shall cause automatic resetting of the timer to its initial setting or to “zero.”

DHS 157.77(2)(d)(d) Manual exposure control. An x-ray control shall be incorporated into each x-ray system so that the operator may terminate an exposure at any time except for any one of the following:

DHS 157.77(2)(e)(e) Automatic exposure controls. When an automatic exposure control is provided, it shall meet all the following requirements:

DHS 157.77(2)(e)2.2. If the x-ray tube potential is equal to or greater than 50 kVp, the minimum exposure time for field emission equipment rated for pulsed operation shall be equal to or less than a time interval equivalent to 2 pulses.

DHS 157.77(2)(e)3.3. The minimum exposure time for all equipment other than field emission equipment shall be equal to or less than one-sixtieth second or a time interval required to deliver 5 mAs, whichever is greater.

DHS 157.77(2)(e)4.4. Either the product of peak x-ray tube potential, current, and exposure time shall be limited to not more than 60 kWs per exposure, or the product of x-ray tube current and exposure time shall be limited to not more than 600 mAs per exposure except that, when the x-ray tube potential is less than 50 kVp, the product of x-ray tube current and exposure time shall be limited to not more than 2000 mAs per exposure.

DHS 157.77(2)(e)5.5. A visible signal shall indicate when an exposure has been terminated and manual resetting shall be required before further automatically timed exposures may be made.

DHS 157.77(2)(f)(f) Exposure duration linearity. For systems having independent selection of exposure time settings, the average ratios of exposure to the indicated timer setting, in units of .001mGy/s (mR/s), obtained at any 2 clinically used timer settings may not differ by more than 0.10 times their sum as expressed as:

DHS 157.77(2)(g)(g) Exposure control location. The x-ray exposure control shall be placed so that the operator may view the patient while making any exposure and at least 1 meter (3.3 feet) from the end of the protective barrier.

DHS 157.77(2)(h)(h) Operator protection, except veterinary systems. X-ray systems, excluding veterinary systems, shall meet all the following requirements to protect the operator during system use, as applicable:

DHS 157.77(2)(h)1.1. Stationary x-ray systems shall be required to have the x-ray control permanently mounted behind a protective barrier such that the operator is required to remain behind the protective barrier during the entire exposure.

DHS 157.77(2)(h)2.2. Mobile and portable x-ray systems used continuously for greater than one week in the same location shall meet the requirements of stationary systems.

DHS 157.77(2)(h)3.3. Mobile and portable x-ray systems used for less than one week at the same location shall be provided with either a protective barrier at least 2 meters (6.5 feet) high for operator protection during exposures or a means to allow the operator to be at least 2 meters (6.5 feet) from the tube housing assembly during the exposure.

DHS 157.77(2)(i)(i) Operator protection for veterinary systems. All stationary, mobile or portable x-ray systems used for veterinary work shall be provided with either a 2 meter (6.5 feet) high protective barrier for operator protection during exposures or a means to allow the operator to be at least 2 meters (6.5 feet) from the tube housing assembly during exposures. Persons within 2.7 meters (9 feet) of the tube or animal during exposures shall be protected with at least 0.25mm lead aprons. Persons restraining the animal during radiography shall be protected with at least 0.25mm lead aprons and full coverage gloves or full coverage mittens containing not less than 0.5mm lead equivalent material. The exposure control may be foot operated.

DHS 157.77(3)(3) Source-to-skin distance. All mobile or portable radiographic systems shall be provided with means to limit the source-to-skin distance to equal to or greater than 30 centimeters, except for veterinary systems.