The ornamental design for a flowmeter, as shown and described.
1. Flowmeter
1.1 : Perspective
1.2 : Perspective
1.3 : Front
1.4 : Back
1.5 : Top
1.6 : Bottom
1.7 : Left
1.8 : Right
The broken lines do not form a part of the claimed design; the present article is a flowmeter detecting a signal from the detector, measuring the flow rate and mass of a fluid (liquid, gas) from the signal, and outputting and displaying the measured value.