Non Intrusive Ultrasonic Flow Meter

During field service work I use
#1 an ultrasonic meter refered to as a electronic sightglass to test for flash gas on refrigeration lines a Tiff brand
#2 an ultrasonic leak detector an Amprobe brand

Is there also an ultrasonic non intrusive flow meter available for field service work
(within financial reach of serivce firms as the above meters and rough service)
to verify refrigerant pounds per minute of flow through a pipe to be converted
to test actual horse power of the compressor and or the system?
as in pounds per minute x refrigerant data = total btus