What must be done before removing a misfire when using millisecond delay detonators?

Before removing a misfire when using millisecond delay detonators, it's essential to test the failed shot with a galvanometer. This procedure allows for the safe assessment of the misfired detonator. The galvanometer helps determine whether there is still an electrical charge present that could activate the detonator. By conducting this test, miners can ensure that it is completely safe to proceed with removal without the risk of an unintended detonation.

Using a galvanometer for this situation is a critical safety protocol in mining operations where the risk of explosives is involved, highlighting the importance of verifying the lack of electrical signal before attempting any further actions with the misfire. This step provides a necessary safeguard to protect personnel and maintain the integrity of the operation.