SUMMARY
An adequate system of automatic exposure control can be used with satisfying results to improve the general film quality in routine radiography.
When short exposure times (less than 0.02 sec. = approximately 0.04 sec. setting‐up time) are necessary, a three‐phase generator with automatic current selection ionometric control is essential.
Both photometric and ionometric methods combined with other systems of rectification are satisfactory where extremely short exposure times are not necessary.
The least satisfactory method is the attachment of either ionometric or photometric sensing devices to generators without falling load characteristics.
Radiographers skilled in the aspects of patients' positioning and conversant with the technical processes involved in automatic exposure control are necessary for success of the system in general radiography.
When considering automatic exposure control equipment, particular enquiry should be made as to the switching method employed and the minimum exposure times available.