© 2019 Department of Petroleum Resources. All rights reserved Department of Petroleum Resources (DPR) PROCEDURE GUIDE

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• If meter zero is out of specification, 
iv. Verify isolation valves are not leaking and check for other potential leak sources. If leaks 
are present, zero verification cannot be performed correctly, 
v. Record current zero value, 
vi. Re-zero the meter and record the new zero value: 
• open upstream and downstream block valves placing meter back into service 
and, 
• evaluate indicated meter zero value against its history to identify the long-term 
performance of the meter zero and potential influences (consult manufacturer). 
1.13 Factory Calibration 
The Coriolis meter shall be calibrated annually and witnessed by DPR officer(s). 
1.13.1 Flow Computer Calculations 
The equations for measuring a gas with a Coriolis meter are summarized with the following 
expressions. 
𝑄𝑚(𝑐𝑜𝑚𝑝𝑒𝑛𝑠𝑎𝑡𝑒𝑑) = 𝑄𝑚(𝑢𝑛𝑐𝑜𝑚𝑝𝑒𝑛𝑠𝑎𝑡𝑒𝑑)(𝐹𝑝) 
Where:  
Qm (compensated)=      Mass flow rate of gas compensated for flow pressure effect 
 Qm (uncompensated) = Mass flow rate of gas uncompensated for flow pressure effect 
 Fp =  
             Flow pressure effect compensation factor 
 
And Fp is given as  
𝐹𝑝=
1
1 + ((𝑃𝑒𝑓𝑓𝑒𝑐𝑡
100 ) ∗(𝑃𝑓−𝑃𝑐𝑎𝑙))
 
 
where 
PEffect = Flow pressure effect in percent of rate per psig  
Pf =  Measurement fluid static pressure in psig  
PCal =  
Calibration static pressure in psig 
 
1.14 Pre-commissioning checklist 
A 
HEADER 
DETAILS 
STATUS 
1 
Company name 
 
 
2 
Date of Inspection 
 
 
3 
Name of Inspector(s) 
 
 
B 
GENERAL INFORMATION 
 
 
1 
Serial number 
 
 
2 
Nominal Pipe diameter