| Popis: |
Domestic gas meters are tested for accuracy of registration using bell provers. Oil has a tendency to form films on the vertical surfaces of the bell, and this paper investigates its effect on the accuracy of the prover. The geometry of the prover and the manner of its operation are both shown to affect the magnitude of the error. The most important physical property of the oil is the kinematic viscosity, ν, and the error is found to be proportional to ✓ (ν). Calculations for an oil having a value for ν of 2·5 × 10 −5 m 2 s −1 indicate a maximum error of about 0·2% under normal operating conditions. The magnitude of the maximum error can be reduced by suitable design of the prover. |
