keskmine vee rõhk (ülerõhk) torus mõõdetuna veearvesti sissevoolu ja väljavoolu avas, gaasi rõhu ja atmosfääri rõhu vahe gaasimõõturi sisselaskeavas, average water pressure (gauge) in the pipe measured upstream and downstream of the water meter, difference between the pressure of the gas at the inlet of the meter and the atmospheric pressure, gas pressure within the piping containing the meter