On water service ...




The ISMA Venturi "exponential" flumes are used to measure drained off flows in an open straight line channel. When the fluvial drain off conditions (no turbulent) are respected at the contraction upstream and the take out water downstream (free drain off with out flowback restraints). Then the water thin plate located upstream the contraction (h: hydraulic loading) is directly bounded with the flow transit (Q).


ISMA auto control consits in:

ISMA Venturi flume with exponential cross section (flat floor)

This flume presents 2 advantages :

1. Important water column with low flow, This important water column is consequently to the Venturi flume section. Example : flume type I : for 0,06 l/s (216 l/h for example), the water column is 18 mm.

2. Flow measuring range on a scale from 1 up to 100 Example : flume type I : the range is from 0,06 l/s up to 6 l/s while this relation is from 1 up to 30 for a rectangular cross section flume. This advantage prevents from the occulting of beginning, end of pumping, the drowning when waste outlet andensures a great precision.

ISMA flowmeters on open flume, type DLK®

This instrument is multi-functions, it allows to manage, in the same time as the flow, other parameters in relation with the measuring site, thanks to its 12 analogical inputs and its 2 numerical inputs. It is possible to connect it with an oxymeter, turbimeter, pH-meter, rain gauge, … and to count the pumps functioning time and the effected samples. It is able too to control a waste-water sampler in function of the pump state and flow at the entrance of a treatment plant. Its analogical and numerical outputs ensure the control of equipment as samplers, dosing pumps, valves…
A software developed by us allows the transmission of the whole memorised values (57000 values) in less than 4 minutes. Its compatibility with Excel ensures a performing data process. ISMA flowmeter is proposed in 2 versions : stationary and portative version. It can be equipped with an ultrasonic or a bubble sensor or the both.

Its printer (optional for the stationary version) restores a report at midnight indicating :

This printing can be adjusted in a hourly pitch and can realise a graphic (only for flow). The ISMA® flowmeters are guaranteed 2 years in our workshop.

Waste water samplers
ISO 5667-10 conformity

The samplers range is well-known for its reliability and its robustness.
The electronic control units are microprocessored and their process ensure an anti-overflowing security.
They are time-, flow-proportional or event-controlled. When the samplers are refrigerated and regulated, the inner temperature of 4° C in the cabinet, is kept to ± 0,5° C, thanks to the high-quality cooling unit.

ISMA® answers to every sampling type. The samplers are able to take samples until 5 to 6 metres depth and, optional, until 8 to 9 metres with vacuum pump system.

These equipments are guaranteed 2 years, in our workshop, in normal using conditions.

THE ISMA Venturi channels curves have been overhauled on a hydraulic bench equipped with electromagnetic flowmeters oveerhauled by COFRAC an accredited organization (documents are free addressed by demand or download on Internet www.isma.fr). A hydraulic study realized by ENGEES (Ecole Nationale du Génie de l'Eau et de l'Environnement de Strasbourg = Strasbourg's Water and Environmental Engineering National School) has confirmed the quality and the precision of these channels.


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