Master Meters and Proving Tanks

The periodic verification and calibration of meters is a necessary operation for maintaining the accuracy levels of meters in service. This requires the use of calibrated reference systems such as proving tanks or master meters.

Master meters and proving tanks are both used to verify the accuracy of flowmeters, but they use a different approach during the calibration activity. Master meters are high-precision meters used to calibrate other meters in service through a smart and simple connection in series towards a tank truck (typically by use of flexible hoses), while proving tanks are large, calibrated reservoirs used to verify the accuracy of flow meters by measuring the level of the fluid that fills.

Both are valid methods, widely used in the oil industry, however the master meter brings a more modern and flexible approach.

• water: in this case field recalibration of the master meter with the product has to be performed;
  
  
• with gasoline, diesel oil or jet fuel: calibration is performed in an accredited laboratory with the required product.

In both cases each master meter is calibrated at increasing flow rates inside its range, and it is always provided with a specific calibration report proving the accuracy, even for different products (typically diesel oil and gasoline).

Master meters can be mounted on trolleys with wheels so that they can also be transported by road to get as close as possible to the meter that has to be calibrated. For a higher level of flexibility, they can also be equipped with additional instrumentation (thermowells, pressure switches) and hoses.

Technical data of master meters:

Master meter applications

Master Meters can be used for calibrating flow meters in a variety of plant configurations, depending on the layout and type of system where the meter under test is installed. The calibration setup must be tailored to the specific operational environment to ensure reliable and accurate results.

Common application configurations include:

1. With a product recovery line – the measured product is returned through a dedicated line for reuse or recirculation.
   
   
2. With a tank truck – the product is temporarily stored in a tank truck during calibration.
   
   
3. With a proving tank – the measured product is collected in a certified volumetric reference tank.

Always ensure that the recovery system (tank or line) has sufficient capacity to contain the total measured volume and that it can handle the maximum flow rate of the meter being calibrated.

Master meter readings

To ensure precise meter calibration, Master Meters are used as reference instruments.

Download here master manual for further info.

Proving tanks applications

Proving tanks are available in both fixed and mobile versions and in different dimensions. Their application depends on the capacity and model. Proving tanks are used as a primary provers to calibrate flowmeters, dosing pumps or analogous proving tanks on secondary lines. They can be trucked on-side to monitor flowmeters installed in loading bays or in different places in the refinery or oil depot.

They offer a reliable reference for precise volumetric measurements. In aviation, refueling stations and terminal facilities, these tools ensure meter reliability and compliance with metrological regulations.

To ensure the highest level of accuracy and compliance in your metering operations, rely on ISOIL’s certified master meters and proving tanks. Whether you operate in the terminal, aviation, petrochemical, or transport sector. Our team is ready to support you with tailored calibration solutions, documentation, and technical assistance.

Contact us today to request a quote, download product datasheets, or schedule a consultation with one of our specialists.