Insertion loss sensor for testing immersion cooling liquids

An insertion loss sensor for measuring insertion loss in a fluid, the insertion loss sensor comprising:

• a printed circuit board defining a first edge;
• a U-shaped detection trace configured to sense insertion loss, the U-shaped detection trace extending along a U-shaped path from a first end to a second end, the first end and the second end both terminating at or near the first edge of the printed circuit board, the U-shaped detection trace being devoid of any sharp corners along the U-shaped path;
• a first connector disposed on the straight edge of the printed circuit board and electrically connected to the first end of the U-shaped detection trace;
• and
• a second connector disposed on the straight edge of the printed circuit board and electrically connected to the second end of the U-shaped detection trace.