The hall monitor politely asked students to keep the noise down between classes.

The hallway monitor asked everyone to walk quietly to their next class.

Holter monitors were used to detect the brief episodes of atrial fibrillation that routine ECGs had missed.

The doctor recommended that I wear a Holter monitor for 24 hours to track my heart rhythm.

As the milk monitor, Sarah lined up beside the classroom sink so she could hand each child a paper carton before morning assembly.

The dairy cooperative purchased new milk monitors to track temperature and bacterial levels during storage.

Bengal monitors basked on the sun-warmed rocks near the riverbank.

A Bengal monitor basked on the sun-warmed rock near the river while anglers watched in awe.

The hall monitors reminded everyone to keep the noise down between classes.

The dungeon monitors checked every corridor for signs of movement before allowing the prisoners to leave.