Duotronic probe

A duotronic probe

A duotronic probe was an engineering tool used aboard Federation starships to regulate plasma flow. However, the gravitic caliper was a more precise instrument. (VOY: "Fair Trade")

It may operate under duotronic computer system principles, which would align with Vorik's statement of it being inferior to the gravitic caliper.
The Doctor used the same device for a medical scan in "Workforce".