Ultrasonic Flowmeters

There's a name at the bottom of the offer letters, correct?

Use the telephone to speak to that person directly, and go from there.

Probably to keep signal-to-noise ratio low....but I'm just guessing

preamp intro...

Here's a nice article on the basics of an ultrasonic flow meter. Now the fundamental reason that a preamplifier is required for a gas media is a fundamental aspect of wave propagation. Regardless of the transducers being "wet" or not the density of a gas is considerably less than any fluid. So more energy is reflected away at every solid/gas boundary than solid/liquid boundary.

A ceramic piezo element couples well to liquid. Gas provides a poor coupling, hence the need for preamplifier. Beyond that, I am with Fred.

usually we don't need that pre amplifier, it s cause different sound speed between liquid and gas, please check your parameter type for gas application, and set for flowing temperature