Low Flow Calibration – limits

The accuracy of the flowmeter can be determined by the change in the pulses per litre value over a flow rate range selected from the calibration certificate.  This document is also available for download from litremeter.com.

  • Repeatability is better than ±0.1% of reading over the top 99% of range.
  • Accuracy with linearisation is better than ±0.5% of reading.

The minimum flow rate achievable depends on many variables but can be reduced to two factors:

  • the viscosity of the fluid. The higher the viscosity, the lower the low flow rate ability
  • the perfection of the meter dimensions and components
  1. Standard (STD) calibration rates can be achieved 99 times out of a 100. No special selection required
  2. Low Flow (LF) calibration requires matched parts and more calibration time
  3. Ultra Low Flow (ULF) calibration requires the best parts and the most patience by our
    calibration engineers. It is highly unlikely we can provide a batch of ULF meters due to their scarcity.

In particular, for LF03, LF05 and LF15, we can compare the low flow limits both on a linear scale and, secondly, on a logarithmic scale, as well as in a traditional table:

VFF flowmeter LF15 – flow range on various viscosities STD vs. LF vs. ULF
VFF flowmeter LF05 – flow range on various viscosities STD vs. LF vs. ULF
VFF flowmeter LF03 – flow range on various viscosities STD vs. LF vs. ULF