Gas Pumps and Meters

Stefan P. Parnay, Agriculture, Weights and Measures - Marin County

Measuring Devices

Instruments used to determine volume, distance, dimensions, and time are all types of measuring devices. The device people are most familiar with is the gas pump. Inside the gas pump housing is a meter that determines the quantity of fuel dispensed. Inspectors test each meter, compare monetary computations, verify the tamper-proof seal on the meter adjustment is intact, and inspect various other requirements.

The Department inspects a wide variety of measuring devices, including:

  • Gas Pumps
  • Taximeters
  • Timers in Car Washes, Laundromats, and Parking Garages
  • Wire and Rope Meters
  • Propane Meters
  • Wholesale Water Meters
  • Milk Tanks
  • Utility Meters for Electricity, Gas, and Water

Each meter type requires its own special test equipment; a taxi test wheel; calibrated tape measures; test vessels and a stopwatch.

Utility meters such as electric, gas, and water, used in mobile home parks are routinely tested.

Each inspection tests the meters ability to accurately register at full and light loads, including confirming other requirements. The installation of the meter directly affects performance. Wiring and meter connections are vital to correct metering of electricity, while plumbing and level installations of gas vapor and water meters are critical to their accuracy. The computation of bills using correct rate schedules is also verified. Calibrations can be either dry or liquid. We test our field standards against our office standards to maintain a chain of accuracy. Our standards are verified by the California Division of Measurement Standards on a routine basis for accuracy.