Gas Monitors & Solutions by OBW Technologies

Nivus Flow Measurement


The Nivus Group is a leading developer, manufacturer and supplier of measurement instruments for the water industry. Their product portfolio comprises metering devices for flow, level, pressure, water quality, density and turbidity as well as providing devices and software for the detection, transfer, recording and evaluation of data.

Nivus Flow Metering By OBW Technologies

Flow Meters for water and waste water at highest level. Very high accuracy – reliable measuring data – universal usability for all types of channels and pipes – full or part filled. Best measuring results due to velocity measurement spatial allocation.

Suitable for full pipe flow measurement or open channel flow measurement.

View Nivus Products and Services


Flow Metering Applications

Channel Networks Monitoring: Portable and permanent measurement systems for continuous measurement of flow and level in channel network systems.

Waste water Treatment Plants: Portable and permanent measurement systems for continuous measurement of flow and level in all areas of waste water treatment plants.

Measurement Campaigns: Device rentals to complete planning, implementation and data evaluation. Used for master plan studies and for the calibration of hydraulic models.

Flowing Waters, Rivers & Channels: Flow measurements in flowing waters for flood protection, calibration and validation of hydrologic calculation models, dimensioning and operation of facilities in water industry.

Industry and Hydro-power – Flow measurements of inlets and outlets conducting cooling water, circulation systems and turbine intakes of power plants and industry, penstock monitoring and turbine efficiency monitoring.

Water Supply & Water Distribution – Measurement of level and pressure in deep wells and conveyor systems as well as flow measurements at elevated tanks, water purification plants and water treatment plants.

The Perfect Solution for every application

Regarding flow measurement in water and waste water NIVUS distinguish between two basic methods:

  1. Flow Velocity Measuring Methods: NIVUS provides portable and permanent metering systems for continuous flow measurement using ultrasonic flow velocity measurement. For any liquid from clean water to waste water and for a variety of flumes such as part filled and full pipes, channels and surface waters, NIVUS supply appropriate measurement systems.
  2. The Hydraulic Method: For classic flow measurement methods on venturi flumes, weirs, dam shutter and similar applications, NIVUS provides appropriate metering and evaluation instruments.

NIVUS provides the best possible measurement method for all applications.

Cross Correlation Method:cross correlation method

Reflectors within the water are scanned by an ultrasonic impulse and subsequently are saved as echo patterns. A second scan follows a few milliseconds later. Correlating both signals allows the calculation of the flow velocity. Repeating this procedure in varying flow levels enables determination of the real flow velocity profile.

  • The measurement method for universal use in slight to heavily polluted water.
  • Very high accuracy.
  • Measures the real flow velocity profile.
  • For use in waste water.


The Doppler Methoddoppler method

The Doppler method uses a continuous ultrasonic signal with a defined frequency and known angle to be sent into the water. The moving particles generate a frequency shift which is proportional to the flow velocity of the particles. These values are used for statistical averaging. The Doppler method cannot be used perform distance – related flow velocity measurements.

  • For measurement in slight to heavily polluted water
  • Latest intelligent fourth-generation Doppler technology


Transit Time Method:transit time method

The transit time method is based on detecting the transit time of ultrasonic signals between two sensors. Here the signal transit time towards the flow direction is shorter than against the flow direction. The difference between the both transit times is proportional to the average flow velocity along the measurement path. The average velocity within the section is calculated by the transmitter.

  • For clean to slightly polluted water
  • Meets IEC 41 requirements
  • Very high measurement accuracy


NIVUS Flow Measurement Product Range:

Flow Velocity Measurement Method Products
Software Solutions
The Hydraulic Method Products
Nivus Level Measurement Products
GPRS Data Logger and Internet Portal Products



Flow Velocity Measurement Method Products




Cross Correlation Method – Permanent Measurement System

The top flow meter for universal use in waste water in full and part-filled channels and pipes.

Suitable for full and part filled channel shapes such as pipe, egg,rectangular, U-profile, trapezoid, detection of large flow volumes and free profiles.

Typical applications include channel network systems, inlets and outlets of waste water treatment plants, billing purposes, discharge control, surface water and storm-water monitoring, CSO, SSO and many more.


NIVUS Full Pipe (NFP)

NIVUS Full Pipe (NFP)

Cross Correlation Method – Permanent Measurement System

Flow measurement in full pipes – the cost effective alternative to EMF.

Suitable for full pipes up to 800mm diameter, for greater diameters see OCM Pro CF.

Typical applications include pump stations for storm water, dirty water and combined waste water, waste water treatment plants, pressure pipelines, drainage lines, return sludge lines, re-circulation lines and many more.




Doppler Method – Permanent Measurement System

Cost-effective flow metering for use in waste water.

Suitable for part filled pipe, egg, rectangular, U, trapezoid and free profiles.

Typical applications include measurements and discharge control in pump stations, storm water treatment facilitates and waste water treatment plants.




Transit Time Method – Permanent Measurement System

Flow measurement for clean to slightly polluted water in full pipes.

Suitable for full pipes and rectangular channels with diameters.

Typical applications include circulation systems, hydro-power plants, between 100 and 1000mm penstock monitoring, turbine efficiency monitoring.



NuvoSonic CO

NuvoSonic CO

Transit Time Method- Clamp On – Permanent Measurement System

Clamp on multi path flow measurement for clean to slightly polluted.

Suitable for full pipes from DN 50 up to DN 6000.

Typical applications include process water in pipes, cooling water, fluids in full pipes circulation systems, hydropower plants, water supply, production and treatment of drinking water, slide valve monitoring , turbine efficiency monitoring.


pcm pro


Cross Correlation Method – Portable

Portable, Ex-protected flow measurement using high accurate ultrasonic cross correlation, measurement of real flow velocity profiles.

Suitable for full and part filled shapes such as pipe, egg, rectangular, U, trapezoid, free profiles and many more.

Typical applications include use in Ex areas, calibration basis of hydraulic calculation models, determination of extent of sewer channel restoration, location of extraneous water loads, throttle verification.


pcm 4


Cross Correlation Method – Portable

Portable flow measurement using high accurate ultrasonic cross correlation, measurement of the real flow velocity profile.

Suitable for full and part filled shapes such as pipe, egg, rectangular, U, trapezoid, 2r egg, free profiles and many more.

Typical applications include use in non Ex areas, calibration basis of hydraulic calculation models, determination of extent of sewer channel restoration, location of extraneous water loads, throttle verification.


Extensions for PCM Pro and PCM 4

(NPP) NIVUS Pipe Profiler – Portable pipe measuring section for PCM Pro and PCM 4

Suitable for pipelines with diameter between DN150 and 600mm.

Typical applications include measurement of low flow volumes, improvement of difficult discharge conditions.

Flexible use in various pipe diameters.

For very low flow volumes.

Measures under full-filled conditions utilizing ideal flow profiles.

Sediment detection thanks to combination with level measurement integrated in flow velocity sensor.


pcm f


Doppler Method – Portable

Cost effective flow metering for universal use.

Suitable for part filled and full shapes such as pipe, egg, rectangular, U, trapezoid, 2r egg, free profiles and many more.

Typical applications include measurements and discharge control in pump stations, storm water treatment facilities and waste water treatment plants.




Transit Time Method/Clamp on – Portable

Portable flow measurement using the transit time method (clamp-on).

Suitable for full pipes from 50 to 3000mm.

Typical applications include drinking water, cooling water, process water, circulation systems.


PCM Pro, PCM 4, PCM Pro 2nd Generation

The PCM Pro, PCM4 and PCM Pro 2 Generation measurement system for portable flow measurements consists of a transmitter Type PCM for power supply, data entry, indication and data storage plus a sensor for the recording of measurement data. Sensor construction as well as the built- in pick-ups may be customised individually according to the conditions prevailing on site.

The NIVUS portable Type PCM units are designed for use in part filled and full channels, pipes and flumes with various shapes and dimensions. The most accurate and most sophisticated flow velocity measurements are available by using the PCM units with the ultrasonic cross correlation.

Used by local councils, water and environment authorities, engineering consultants and planning agencies, test centres or authorised experts – with its versatile and universal areas of use, its high accuracy and user friendliness the PCM represents a long-life and reliable working flow meter.

Features & Benefits

Easy and quick to start-up.

  • Thanks to the alphanumeric keypad and the back-lit 128 x 128 pixel display, parameters can be set and readings as well as status messages can be indicated without the need to use additional aids.

Easy operation even under poor conditions.

  • Due to the compact construction, the PCM can be easily installed in manholes, featuring a weight of 6.2Kg including the rechargeable battery; the PCM is the “lightweight” among the transmitters. There is no additional grounding connection required and the very robust enclosure protects the electronic components against mechanical and chemical influences as well as effects of weather.

Easy assessment of measurement places.

  • Due to the lack of calming sections, poor ambient conditions and the need to operate in public traffic areas, channel network measurements are among the most difficult measuring tasks.Thanks to the ultrasonic cross correlation the measured flow profile can be indicated directly on the transmitter. This worldwide unique feature gives the safety of having the best possible measurement right from the start up.

Redundant data storage.

  • The PCM uses two completely independent memory media which virtually eliminates data loss.

The right sensor for each application

There are flow velocity sensors with and without integrated level measurement as well as air-ultrasonic level sensors. Depending on the application there are varying constructions available. The Type “Mini” sensor family provides the best possible measurement system to detect lowest discharges e.g. for measurement of extraneous water or indirect discharge measurements. Optimised mounting accessories enable easy sensor installation.

Features & Benefits

  • Sensors are absolutely drift-free and have a stable zero point.
  • Low installation expenses thanks to perfectly coordinated accessories.
  • Can be installed under process conditions.
  • Interference-free connection over long distances through digital signal transmission.


air ultrasonic sensor

Air-Ultrasonic Sensor

For level measurement, installation on channel crown.

wedge sensor

Wedge Sensor

For installation on the channel bottom or channel wall.

pipe sensor

Pipe Sensor

For installation in pipes using nozzle and cutting ring screw joint and in NIVUS Pipe Profiler.

nivus product brochure


Software Solutions



NivuSoft is software with precisely adjusted functions for processing of measurement data in the water industry. It provides a variety of options for the visualization and evaluation of measurement data up to reporting functions. The software operates local and communicates with the “D2W- Device to Web” on-line data portal in order to directly receive and to further process saved readings.


The Hydraulic Method Products

Hydraulic Calculator Plus Nivus OBW Technologies

Measurement on Weirs: Different kinds of weirs (e.g. overflow weirs, triangular weirs and similar) are in use depending on the flow volumes. The overflow height is a measure for the flow.

  • HydraulicCalculator Plus: Flow measurement instrument for calculation of overflow volumes on sills, weirs and special constructions tending to backwater formation or with tangential streaming according to ATV A111.Venturi Flumes Nivus OBW Technologies

Measurements on Venturi Flumes: Venturi measurements are flow measurements in particularly shaped flow channels, where a contraction creates a change of the flow velocity from streaming to shooting. Impoundage height and flow correlate exponentially with each other: this allows to calculate flow from the flow level measurement.

  • Venturi Flumes: The dimensions are adjusted to the channel width and to the maximum expected flow volume. The Venturi Flume is calculated according to DIN 19559 Part 2. Available as half shells or as complete unit in many sizes.NIVUS NDW OBW Technologies

NDW: The inclinometer utilises a capacitive measurement method for inclination measurement (angle measurement) on dams. Ex approval (optional), wear free and maintenance free, robust and corrosion resistant, submersible (IP 68).




Level Measurement Products

Please Contact Us For Further Information

  • Continuous Measurement Systems
  • Ultrasound
  • Hydro-static, Pressure



GPRS Data Logger and Internet Portal Products:

Data Logger: The NIVUS GPRS Data Loggers enable stand-alone operation of measurement places, e.g. for level and tank monitoring, level measurement and limit level monitoring independent from mains power. Recorded data is transmitted to the D2W (Device 2 Web) internet portal using GPRS.obw technologies data logger

  • Unlimited access to your measurement data via internet
  • Extremely long battery life of up to 5 years
  • For use in Ex zone 1
  • Comprehensive possibilities such as remote parameter setting, alarm functions, monitoring and calculation of limit values via D2W internet portal.
  • Stable and cost-efficient data transmission.


nuvi log easy

NivuLog Easy


Compact GPRS data logger with 4 inputs

Typical Applications

Level monitoring, level measurement in storm-water tanks, rain gauge, silo system monitoring.



nuvi log easy sun

NivuLog Easy Sun NivuLog Sunflow


GPRS data logger in solar panel enclosure

Typical Applications

Level monitoring, level measurement in storm-water tanks, rain gauge, silo system monitoring, flow measurement (NivuLog Sunflow)



nuvi log 4

NivuLog 4 NivuLog 2 Ex


GPRS data logger with 4 inputs

GPRS data logger with 2 inputs for Ex area

Typical Applications

Measurement in Ex areas, level monitoring, level measurement in stormwater tanks, limit level monitoring, volume calculation.



nuvi log 4

NivuLog PCM NivuLog PCM Ex


GPRS data logger for direct connection to PCM Pro (Ex) or PCM 4 (non Ex)

Typical Applications

Connection to PCM, measurement in Ex areas, flow monitoring, limit value alarms , PCM battery monitoring, optimisation of maintenance cycles



level data collector

Level Data Collector


Level measurement system for data transmission via GPRS to D2W internet portal or USB interface

Typical Applications

Level Measurement



internet portal dw2 obw technologies 

Internet Portal D2W:


The “D2W” Device 2 Web internet portal is a comprehensive data management system saving the measurement data transmitted from the data logger via GPRS. Moreover there is a variety of options available for the direct analysis of measurement data, for system monitoring, forwarding of data and alarm functions.



Nuvi Log H2s & h2s mini

NivuLog H2S & NivuLog H2S Mini


Portable measurement instrument for detection of H2S concentration in channel networks

Typical Applications

Waste-water treatment plants, industries, public water and sewage systems