Which of the following is not an acceptable way to secure a portable gauge in a locked storage area?

Securing a portable gauge correctly is critical to ensuring safety and compliance with regulatory standards. The option that mentions using a single lock on the storage door is not considered an acceptable way to secure a portable gauge because it may not provide adequate security. A single lock can be compromised easily, and does not account for the fact that additional security measures should be in place to prevent unauthorized access.

In contrast, storing the gauge inside a locked cabinet offers a physical barrier, making it difficult for unauthorized individuals to access the device. Securing the gauge to a non-portable structure with a cable further enhances security by preventing the entire device from being moved. Lastly, using a locked storage shed with a secured outdoor area provides multiple layers of protection, making it less likely that someone could access the gauge without proper authorization. These methods collectively enhance safety and prevent unauthorized use of the gauge, which is crucial for anyone handling nuclear materials.