What is the standard control limit for the field light to radiation field alignment test?

The standard control limit for the field light to radiation field alignment test is ±2% of the Source-to-Image Distance (SID). This measurement is critical to ensure that the collimation and the actual radiation field are accurately aligned, as improper alignment can lead to inaccuracies in imaging and unnecessary radiation exposure. Maintaining this standard is essential for the safety of patients and the effectiveness of the imaging process.

The ±2% margin acknowledges that minor discrepancies can occur due to equipment variability and other factors, while still ensuring that the radiation field closely matches the illuminated field. This limit is grounded in established safety and quality assurance protocols within radiography, helping to provide consistent and reliable imaging outcomes.