Ultraflux Uf 811, User Manual, Page: 9 / 104

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NT UF 811 CP GB (e) / June 2015
1.12 Functions
 Recording options : The flow meter is used to record the measurement data (logger function). Up
to 30 variables can be recorded (for example: average flow, minimum flow, maximum flow, water
level). A total of 530,000 readings can be recorded. The frequency and sequencing of the
recordings can be adjusted.
 Echo display : It is possible to display the measurement echo for each chord, which allows you in
particular to check the quality of the measurement and directly view the effect of certain corrective
actions (positioning and alignment of the probes, adjustment of the settings, cleaning of the
probes, etc.).
 Four flow volume totalizers which can count the positive flows, negative flows or total flows,
regardless of their sign,
 Filtering of the measurement using a first-order filter allowing the non-significant flow
fluctuations to be smoothed,
 Storage of the measurement in memory in the event of a momentary loss of the echo (due, for
example, to the passing of air bubbles) or other faults (adjustable storage interval),
 Setting the measurement to zero if the flow is below a programmable value,
 Readjustment of the zero if it is possible to completely stop the flow.
1.13 Performance of the flow meter
 Uncertainty over measured speed: up to ±0.5 %.
 Repeatability: up to 0.1 %.
 Linearity: up to 0.1 %.
 Typical uncertainty on the flow rate calculation: from 0.5 to 5 % depending on the application and
the number of chords.
Important: The accuracy of the measurement also depends on the accuracy with which the geometry of
the measuring point is measured, the dimensions of the probe pairs, the distance between the probes and
the length the wave has to travel between two probes. An inaccuracy on one of these values may
compromise the accuracy of the measurement.
1.14 Cleaning the flow meter
The box may be cleaned with water, diluted alcohol or detergent using a sponge or a soft cloth. Do not use
abrasive materials or solvents.
1.15 Recycling the flow meter
In the context of decree no. 2005-829 dated 20 July 2005 relating to the collection, treatment and disposal
of electrical and electronic equipment in France, Ultraflux delegates the responsibility for financial and also
logistical recovery to the user, who will manage their own waste.