A flow metering system , comprising: an ultrasonic flow metering system comprising: an ultrasonic flow meter having a meter body defining a central passage, the ultrasonic flow meter constructed to be coupled to a structure carrying fluids, and configured to measure volume of fluid flowing through the central passage; and a first pressure sensor disposed in the meter body or downstream of the ultrasonic flow meter to measure pressure of the fluid proximate the ultrasonic flow meter ; a flow conditioner disposed upstream of the ultrasonic flow meter ; a second pressure sensor disposed upstream of the flow conditioner to measure pressure of the fluid upstream of the flow conditioner ; and a condition monitor coupled to the ultrasonic flow meter and the pressure sensors , and configured to: identify a potential discrepancy in operation of the flow metering system based on a difference between pressure measurements of the first and second pressure sensors ; establish a reference pressure difference between the first and second pressure sensors ; and compute an expected value of pressure proximate the ultrasonic flow meter based on the reference pressure difference and the pressure measured by the second pressure sensor . an ultrasonic flow metering system comprising: an ultrasonic flow meter having a meter body defining a central passage, the ultrasonic flow meter constructed to be coupled to a structure carrying fluids, and configured to measure volume of fluid flowing through the central passage; and a first pressure sensor disposed in the meter body or downstream of the ultrasonic flow meter to measure pressure of the fluid proximate the ultrasonic flow meter ; an ultrasonic flow meter having a meter body defining a central passage, the ultrasonic flow meter constructed to be coupled to a structure carrying fluids, and configured to measure volume of fluid flowing through the central passage; and a first pressure sensor disposed in the meter body or downstream of the ultrasonic flow meter to measure pressure of the fluid proximate the ultrasonic flow meter ; a flow conditioner disposed upstream of the ultrasonic flow meter ; a second pressure sensor disposed upstream of the flow conditioner to measure pressure of the fluid upstream of the flow conditioner ; and a condition monitor coupled to the ultrasonic flow meter and the pressure sensors , and configured to: identify a potential discrepancy in operation of the flow metering system based on a difference between pressure measurements of the first and second pressure sensors ; establish a reference pressure difference between the first and second pressure sensors ; and compute an expected value of pressure proximate the ultrasonic flow meter based on the reference pressure difference and the pressure measured by the second pressure sensor . identify a potential discrepancy in operation of the flow metering system based on a difference between pressure measurements of the first and second pressure sensors ; establish a reference pressure difference between the first and second pressure sensors ; and compute an expected value of pressure proximate the ultrasonic flow meter based on the reference pressure difference and the pressure measured by the second pressure sensor . <EOS>