A production line uses a gamma source and a detector to monitor the thickness of moving rolled steel. The control system is set to maintain a steel thickness of 5.0 mm.
| Measurement | Count rate |
|---|---|
| Background radiation | 20 counts per minute |
| Steel of thickness 5.0 mm | 520 counts per minute |
| Steel being produced | 560 counts per minute |
Calculate the corrected count rate for the target thickness and for the steel strip being produced. Use your results to state whether the strip is too thick or too thin and state what the control system should do.