Sensor pallet
A sensor pallet was a device that required diagnostics from time to time.
In 2369, Ensign Janeway ran a diagnostic on the sensor pallets and found a 0.23 variance, which was within specifications. However, Lieutenant Pinder questioned her satisfaction with the discrepancy. It was one example of the many times she felt he went out of his way to be critical, and she gave this incident as an example to Counselor Deanna Troi of Pinder's poor treatment of her. (TNG: "Man Of The People")