TEXAS AIRFLOW MEASUREMENT SYSTEMS EXAM STUDY GUIDE | TESTBANK |
PRACTICE QUESTIONS & ANSWERS | EXAM PREPARATION | CERTIFICATION EXAM
| LATEST UPDATE 2026/2027
Examiner:
Texas Railroad Commission (RRC)
TABLE OF CONTENTS
1. Texas Rules and Regulatory Requirements
2. Natural Gas Measurement Principles
3. Airflow Measurement Systems
4. Differential Pressure Measurement
5. Flow Measurement Calculations
6. Meter Tubes and Meter Runs
7. Orifice Meters
8. Ultrasonic Measurement Systems
9. Turbine Meter Systems
10. Gas Properties and Compressibility
11. Pressure and Temperature Compensation
12. Electronic Flow Measurement (EFM)
13. Calibration and Verification
14. Measurement Uncertainty and Error Analysis
15. Sampling and Gas Quality
16. Inspection, Maintenance, and Troubleshooting
17. Documentation and Recordkeeping
18. Safety Requirements
19. Professional Ethics
20. Scenario-Based Regulatory Compliance
,Keywords: Airflow Measurement || Natural Gas Measurement || Texas Railroad
Commission || Measurement Accuracy || Differential Pressure || Static Pressure || Flow
Rate || Orifice Plate || Meter Tube || Ultrasonic Meter || Turbine Meter || Electronic
Flow Measurement || Calibration || Verification || Pressure Compensation ||
Temperature Compensation || Gas Compressibility || AGA Standards || API Standards ||
Compliance || Custody Transfer || Instrumentation || Diagnostics || Troubleshooting ||
Documentation || Measurement Uncertainty || Inspection || Safety || Professional
Judgment || Regulatory Compliance
DISCLAIMER
This is a PRACTICE EXAMINATION created solely for educational and study
purposes.
It is NOT the actual examination.
The questions are ORIGINAL practice questions inspired by the style, structure,
format, and knowledge areas commonly assessed in previous examinations.
Do not claim or imply that any question comes from a real or confidential exam.
QUESTION 1.
A custody-transfer airflow measurement station consistently reports volumes
approximately 2.8% higher than downstream verification measurements. Inspection
confirms that pressure and temperature transmitters are within calibration tolerances,
and gas composition has remained stable. Which action should be performed FIRST
to identify the most probable source of systematic error?
A. Verify the installed orifice plate bore diameter, orientation, and condition.
B. Replace the differential pressure transmitter.
C. Increase the sampling frequency of the electronic flow computer.
D. Recalculate gas compressibility using historical gas analysis.
, Correct Answer: A. Verify the installed orifice plate bore diameter, orientation,
and condition.
Explanation: A damaged, incorrectly installed, or improperly sized orifice plate
commonly introduces systematic measurement bias while pressure and
temperature devices remain within specification. Replacing instrumentation
without evidence is premature, increasing sampling frequency does not correct
measurement bias, and recalculating compressibility is unlikely to resolve a
persistent error when gas composition has remained stable.
────────────────────────────────────────
QUESTION 2.
An operator discovers that an electronic flow measurement system lost
communication with its supervisory control system for six hours. The flow computer
continued recording local measurement data without interruption. What is the most
appropriate compliance response?
A. Estimate production using historical averages.
B. Retrieve the locally stored measurement records and verify their integrity before
reporting.
C. Discard the affected measurement period.
D. Reconstruct volumes solely from compressor operating logs.
Correct Answer: B. Retrieve the locally stored measurement records and verify
their integrity before reporting.
Explanation: Loss of communications does not necessarily indicate loss of
measurement data. The locally stored records should be validated and used if their
integrity is confirmed. Estimation methods should only be considered when reliable
measured data are unavailable, while compressor logs alone are insufficient for
custody-transfer reporting.
────────────────────────────────────────
, QUESTION 3.
Following replacement of an orifice plate, technicians observe unstable differential
pressure readings despite stable upstream operating conditions. Which condition is
MOST likely responsible?
A. Excessively high gas heating value.
B. Incorrect atmospheric pressure correction.
C. Turbulence caused by inadequate upstream straight pipe.
D. Excessive gas compressibility factor.
Correct Answer: C. Turbulence caused by inadequate upstream straight pipe.
Explanation: Flow disturbances created by insufficient upstream straight-run
requirements can produce unstable velocity profiles, resulting in fluctuating
differential pressure measurements. Atmospheric pressure, gas heating value, and
compressibility primarily affect calculations rather than creating unstable
differential pressure signals.
────────────────────────────────────────
QUESTION 4.
During calibration, a pressure transmitter exhibits increasing deviation as pressure
approaches its upper range limit. Which instrument characteristic is MOST likely
degrading?
A. Repeatability.
B. Resolution.
C. Linearity.
D. Display contrast.
Correct Answer: C. Linearity.
PRACTICE QUESTIONS & ANSWERS | EXAM PREPARATION | CERTIFICATION EXAM
| LATEST UPDATE 2026/2027
Examiner:
Texas Railroad Commission (RRC)
TABLE OF CONTENTS
1. Texas Rules and Regulatory Requirements
2. Natural Gas Measurement Principles
3. Airflow Measurement Systems
4. Differential Pressure Measurement
5. Flow Measurement Calculations
6. Meter Tubes and Meter Runs
7. Orifice Meters
8. Ultrasonic Measurement Systems
9. Turbine Meter Systems
10. Gas Properties and Compressibility
11. Pressure and Temperature Compensation
12. Electronic Flow Measurement (EFM)
13. Calibration and Verification
14. Measurement Uncertainty and Error Analysis
15. Sampling and Gas Quality
16. Inspection, Maintenance, and Troubleshooting
17. Documentation and Recordkeeping
18. Safety Requirements
19. Professional Ethics
20. Scenario-Based Regulatory Compliance
,Keywords: Airflow Measurement || Natural Gas Measurement || Texas Railroad
Commission || Measurement Accuracy || Differential Pressure || Static Pressure || Flow
Rate || Orifice Plate || Meter Tube || Ultrasonic Meter || Turbine Meter || Electronic
Flow Measurement || Calibration || Verification || Pressure Compensation ||
Temperature Compensation || Gas Compressibility || AGA Standards || API Standards ||
Compliance || Custody Transfer || Instrumentation || Diagnostics || Troubleshooting ||
Documentation || Measurement Uncertainty || Inspection || Safety || Professional
Judgment || Regulatory Compliance
DISCLAIMER
This is a PRACTICE EXAMINATION created solely for educational and study
purposes.
It is NOT the actual examination.
The questions are ORIGINAL practice questions inspired by the style, structure,
format, and knowledge areas commonly assessed in previous examinations.
Do not claim or imply that any question comes from a real or confidential exam.
QUESTION 1.
A custody-transfer airflow measurement station consistently reports volumes
approximately 2.8% higher than downstream verification measurements. Inspection
confirms that pressure and temperature transmitters are within calibration tolerances,
and gas composition has remained stable. Which action should be performed FIRST
to identify the most probable source of systematic error?
A. Verify the installed orifice plate bore diameter, orientation, and condition.
B. Replace the differential pressure transmitter.
C. Increase the sampling frequency of the electronic flow computer.
D. Recalculate gas compressibility using historical gas analysis.
, Correct Answer: A. Verify the installed orifice plate bore diameter, orientation,
and condition.
Explanation: A damaged, incorrectly installed, or improperly sized orifice plate
commonly introduces systematic measurement bias while pressure and
temperature devices remain within specification. Replacing instrumentation
without evidence is premature, increasing sampling frequency does not correct
measurement bias, and recalculating compressibility is unlikely to resolve a
persistent error when gas composition has remained stable.
────────────────────────────────────────
QUESTION 2.
An operator discovers that an electronic flow measurement system lost
communication with its supervisory control system for six hours. The flow computer
continued recording local measurement data without interruption. What is the most
appropriate compliance response?
A. Estimate production using historical averages.
B. Retrieve the locally stored measurement records and verify their integrity before
reporting.
C. Discard the affected measurement period.
D. Reconstruct volumes solely from compressor operating logs.
Correct Answer: B. Retrieve the locally stored measurement records and verify
their integrity before reporting.
Explanation: Loss of communications does not necessarily indicate loss of
measurement data. The locally stored records should be validated and used if their
integrity is confirmed. Estimation methods should only be considered when reliable
measured data are unavailable, while compressor logs alone are insufficient for
custody-transfer reporting.
────────────────────────────────────────
, QUESTION 3.
Following replacement of an orifice plate, technicians observe unstable differential
pressure readings despite stable upstream operating conditions. Which condition is
MOST likely responsible?
A. Excessively high gas heating value.
B. Incorrect atmospheric pressure correction.
C. Turbulence caused by inadequate upstream straight pipe.
D. Excessive gas compressibility factor.
Correct Answer: C. Turbulence caused by inadequate upstream straight pipe.
Explanation: Flow disturbances created by insufficient upstream straight-run
requirements can produce unstable velocity profiles, resulting in fluctuating
differential pressure measurements. Atmospheric pressure, gas heating value, and
compressibility primarily affect calculations rather than creating unstable
differential pressure signals.
────────────────────────────────────────
QUESTION 4.
During calibration, a pressure transmitter exhibits increasing deviation as pressure
approaches its upper range limit. Which instrument characteristic is MOST likely
degrading?
A. Repeatability.
B. Resolution.
C. Linearity.
D. Display contrast.
Correct Answer: C. Linearity.
