What are the steps in field checking an SSR 90?

The correct answer involves a series of essential steps for properly checking the SSR 90, which is an important piece of safety equipment in mine rescue operations.

The first step is to "Check seal," ensuring that the unit has not been tampered with and remains intact for accurate readings. Next, "Check future date" refers to verifying that the equipment is still within its operational lifespan, which is critical for reliability in emergency situations. Followed by "Check general condition," this step involves assessing the physical state of the SSR 90 to confirm that there are no visible damages or issues that could impact its performance. Lastly, "Check the strap" is crucial, as a secure strap is vital for correctly equipping the device and ensuring that it stays in place during an emergency response.

The other options do not cover the necessary steps for field checking the SSR 90 as comprehensively or accurately as this series of checks does. For instance, checking the battery, while important in an overall equipment check, is not listed as a specific step for the SSR 90. Similarly, calibration and expiry dates might not be directly relevant in the immediate field-checking process compared to the direct elements listed in the correct answer. Overall, the focus on integrity, operational readiness