The indicator needle should be on what before use?

• A. Yellow
• B. Red
• C. Blue
• D. Green

Answer: (D)

Green indicates readiness. The indicator uses color-coded zones to signal whether the instrument is within normal operating limits and properly calibrated. Before use, the needle should be in the green zone to confirm the device is ready and safe to operate. If it sits outside green, follow the troubleshooting steps (such as recalibration or battery/sensor checks) to bring it back into the green range before proceeding.