Abstract: The present invention provides a wide range fluid flowmeter, having a body with a central air flow passage and a target in the air flow passage to direct fluid flow to one of the first and second flow loops. The fluid alternates between the first and second flow loops to create an oscillatory system, whose frequency can be measured to determine fluid flow rate. A preferred frequency measuring device is a piezoelectric diaphragm provided within the body of the flowmeter. In a preferred embodiment, a low flow rate sensor is provided in a nozzle of the flowmeter proximal the inlet to the body of the oscillatory, high flow rate flowmeter. The low flow rate sensor can incorporate a convection system which measures flow rates beyond the lower scale of the oscillatory flowmeter, thereby providing an apparatus and a method for measuring flow rates in a compact flowmeter, and with greater efficiency than previous apparatuses and methods.

Abstract: The present invention is directed to a seal for demountable joints operating over a wide temperature range down to liquid helium temperatures. The seal has anti-extrusion guards which prevent extrusion of the soft ductile sealant material, which may be indium or an alloy thereof.