OMNI 4000/7000 Operations and Maintenance Guide
– Rev F
3-16
OMNICONNECT® Operations
3.5
Proving Functions
3.5.1 Prove Types
The three types of liquid proving options are: Conventional, Pulse Interpolation and Master Meter
(gas only supports Master Meter).
Use the Conventional prover option or ball prover if more than 10,000 flow meter pulses are
accumulated between detectors. If less than 10,000 pulses are accumulated between detectors,
use Pulse Interpolation (double chronometry) proving, also known as compact or small volume,
for improved pulse resolution.
An E-combo module card is required for a Pulse Interpolation or small
volume-type prover.
For both Conventional and Pulse Interpolation, you can select the type of pipe setup:
unidirectional or bi-directional. In a unidirectional pipe, there is no reversal of flow meter flow,
although you may still have different sphere and valve arrangements. The 4-way valve in the
bi-directional type of prover can reverse the direction of flow through the prover.
Master Meter proving compares the flow through a designated and certified Master Meter against
the flow through the custody meter to determine a correction factor. Master Meters are usually
independently calibrated and certified by a third-party laboratory to provide a high level of
accuracy to prove other flow meters in the field.
A Meter Factor Linearization feature can be included in flow computers for liquid
applications. After each prove completes and the meter factor accepted, the flow
computer automatically adjusts a meter factor curve. This feature can be applied
regardless of the prove type.
Refer to the Technical Bulletin TB-970803B Meter Factor Linearization for more
information. This bulletin is for the OMNI 3000/6000 flow computers. You can use
the OMNICONNECT database browser to look up the 6000 Modbus register to
determine the corresponding 4000/7000 registers.
