ASNT Industrial Radiography Radiation Safety Practice Test

At which radiation exposure rate must a rate alarm meter activate an audible alarm?

1. 200 mR/h

2. 300 mR/h

3. 400 mR/h

4. 500 mR/h

The correct answer is: 500 mR/h

The correct threshold for a rate alarm meter to activate an audible alarm is established to ensure safety during radiographic operations. When the exposure rate reaches 500 mR/h, the alarm activates to alert personnel of potentially hazardous radiation levels. This standard is in place to prevent individuals from being exposed to elevated radiation levels without their knowledge, thus ensuring that they can take appropriate action, such as moving away from the radiation source or employing necessary protective measures. Adhering to this threshold is crucial for maintaining safe working conditions and minimizing the risk of radiation exposure. Other thresholds, such as 200 mR/h, 300 mR/h, or 400 mR/h, are considered below the level at which the audible warning mechanism is designed to engage. This allows for a proactive approach to protecting personnel, as activation at 500 mR/h serves as a critical alert point in radiographic environments.