Understanding Fuel Dispensing Meter Accuracy

The Misconception of High-Speed Pumps

It’s common for customers to assume that faster pumps equate to faster refuelling times. However, this isn’t always the case. High-speed pumps, such as those dispensing fuel at 90 litres per minute, may not be suitable for smaller vehicles like cars or light vans. These vehicles have smaller tanks, and the automatic fuel nozzle may continuously click off, leading to inefficient refuelling processes and wasted time.

The Importance of Accurate Dispensing Meters

Similarly, the accuracy of dispensing meters is crucial. Customers might invest in the most accurate meter available, but if that meter hasn’t been calibrated with the specific fluid they’re dispensing, such as HVO (hydrotreated or hydrogenated vegetable oil), the accuracy can be compromised. HVO has a lower density than diesel, necessitating regular recalibration of equipment to maintain dispensing accuracy. Routine recalibration isn’t just a best practice; it’s essential, particularly as fuel usage increases, leading to more wear on the meter.

For those using sophisticated fuel management systems (FMS), it’s vital to remember that these systems are only as accurate as the meters they are linked to. An old, inaccurate meter, even if it’s electronic, will degrade the accuracy of the entire system. It’s the type of meter and its calibration, not its appearance, that determines accuracy.

The Calibration Process: Getting It Right

One of the most critical factors in ensuring meter accuracy is the calibration process. The calibration vessel used and its size play a significant role. For instance, we’ve encountered situations where end-users calibrated meters using old, dented metal buckets, leading to inaccurate measurements. This highlights the importance of using proper test measures or proving cans, and having an experienced fuel engineer conduct the calibration. This professional oversight ensures the meter is correctly calibrated, and a test certificate is issued.

Even for non-resale pumps, uncalibrated meters can lead to inaccurate fuel records, resulting in fuel losses that can be costly for the business.

How Accurate Do You Need Your Dispensed Fuel to Be?

This is the fundamental question every customer should ask. While higher accuracy pumps and meters come with a higher upfront cost, they can quickly pay for themselves if you’re using significant quantities of fuel. For smaller fleets, lower-cost, lower-accuracy pumps may suffice, but for larger operations, the investment in precision can lead to substantial savings.

Types of Fuel Meters

There are two primary types of meters found in most fuel pumps:

Flowmeters (Nutating Disc Meters)

• Approximate accuracy: +/- 2% to +/- 1%
• Accuracy varies with delivery speed and fuel type
• Should be calibrated after installation and checked regularly
• Less suitable for topping up tanks to the brim, as accuracy may decrease further

Piston Meters (Positive Displacement Meters)

• Accuracy: +/- 0.5% to +/- 0.25%
• Accuracy remains consistent at different delivery speeds, making them ideal for precise refuelling
• Calibration should be checked after installation and typically rechecked annually unless fuel usage is particularly high

The difference in accuracy can have a significant impact on fuel costs. For example, a meter with +/- 2% accuracy could result in a 4-litre uncertainty per 100 litres dispensed, whereas a meter with +/- 0.5% accuracy reduces this uncertainty to just 1 litre. Over time, this can equate to substantial savings, especially for businesses using large volumes of fuel.

Hytek’s Solution for Meter Calibration

Hytek offers a range of high-quality, affordable test measure cans that have been refined over the years based on customer feedback. Made from durable 304 stainless steel, these cans are suitable for a variety of fuels, including diesel, HVO, biodiesel, petrol, kerosene, and AdBlue®. Available in 5L, 10L, and 20L sizes, they feature a screen-printed scale resistant to petrol and diesel, ensuring accurate measurements under any conditions.

Each can is designed for ease of use, with separate lifting and emptying handles, and includes a clear, easy-to-read gauge. For those needing UK weights and measures certification, Hytek offers certified models for verifying the accuracy of fuel dispensing equipment.

Hytek also provides protective carry cases and anti-splash funnels, ensuring both the engineer’s safety and the longevity of the equipment. Hytek’s products are available for same-day dispatch, ensuring you have the tools you need when you need them.

Conclusion

Fuel meter accuracy is more than just a technical detail; it’s a vital component of efficient fuel management. Investing in accurate meters and ensuring regular calibration saves businesses significant costs in the long run. With Hytek’s range of products, you can ensure your fuel dispensing equipment is always performing at its best, giving peace of mind and precise control over fuel usage.

Please note

If using with AdBlue® do not cross contaminate. AdBlue® is a registered trade mark of the Verband der Automobilindustrie e.V. Hytek only supply the trade, for your copy of their latest product catalogue please email sales@hytekgb.com or call +44 (0) 1279 815 600.