Portable AV-Flowmeter

Language options: English, French, Spanish, Italian, Portuguese

Perfect for short term and extended field studies with the highest quality performance and competitively priced.

Designed for use in the harshest of field conditions the Mainstream Portable flowmeter is constructed from ultra high impact structural copolymer polypropylene, is fully submersible and highly resistant to chemical attack.

This product operates with:

  • Level Sensor standard 10 metre length (varying lengths available upon application) Code: P7002
  • Velocity Sensor standard 10 metre length (varying lengths available upon application) Code: VP003
  • Comms Cable (USB or RS232)
  • Software
  • User Manual
  • Portable Flow
  • Portable Flow Product
  • Portable Flow Box
  • High sensitivity extends applications to ‘clean’ water
  • Sophisticated ultrasound processing ignores spurious signals
  • n Ultrasound signal quality monitor confirms measurement integrity
  • Real-time processing of velocity signals thereby reducing power consumption
  • Smart power saving mode – intelligent use of power saving which automatically reduces the measurement time for high flow velocities and high signal qualities and increases the measurement time for low velocities and low signal qualities
  • Quick to install – no weirs or flumes
  • Powerful, easy to use PC software simplifies transmitter commissioning
  • Streamlined velocity probe eliminates fouling and reduces flow disturbances
  • Distances up to 500 meters from system unit to velocity sensor
  • ATEX Zone 0 velocity sensor, options available (to be used with barriers)

Mainstream uses the area-velocity method to give a continuous or time sample measurement of fluid flow. Mainstream uses a streamlined probe that operates immersed in the flowing liquid. The velocity probe transmits ultrasound into the liquid to create a zone of inspection. Bubbles and solid particles carried through this zone by the flow, even when present in only minute quantities, reflect ultrasound back to the probe.

The received ultrasound signal is processed to produce a histogram of the flow velocities. Analysing this histogram gives the mean flow velocity. Only signals containing verified velocity information are used, thereby ensuring measurement integrity.

Liquid level is measured by a submerged pressure transmitter or ultrasonic sensor. The flow cross-sectional area is deduced from the liquid level measurement and the stored description of the channel or pipe cross section. The flow rate is the flow velocity multiplied by the flow cross-sectional area.

level measurement

Transducer Type: Any 4-20mA current loop level sensor
Method: Pulse activation with configurable sensor warm-up time. Loop current measurement by self-calibrating 16-bit
delta-sigma A-D converter
Current Range: 0-30mA
Resolution: Better than 1µA
Transducer Calibration: Calibration table (maximum 23 points) with built-in interpolator converts loop current into level
measurement Simple transducer calibration tool included in UI software
Interchangeability: Transducers and calibration data directly interchangeable between Mainstream system units

velocity measurement

Transducer Type: Submerged ultrasonic sensor containing signal generator, transmitter, receiver and decoder electronics
Method: Phase Coherence time delay measurement determines the time for tracers carried by the flow to travel a
fixed distance (~ 0.75 mm)
Velocity Range: -5 m/s to -10 mm/s and 10 mm/s to 5 m/s
Resolution: Better than 1 mm/s
Measurement Integrity: Ultrasound signal quality monitor gives the percentage of the measurement time that the received ultrasound
signal contains useful velocity information
Smart Power Saving: Each velocity measurement is based on the same quantity of information. Automatically reduces the
measurement time for high flow velocities and high signal qualities and increases the measurement time for
low velocities and low signal qualities

derived measurements

Area: Flow cross-sectional area calculated from the level measurement and the dimensions of the pipe or channel.
Calculation can take into account a specified (constant) silt level. Flow cross-section specification tools
included in UI software
Flow Rate: Fluid flow rate calculated by multiplying cross-sectional area by flow velocity
Flow Quantity: Three independent flow totalisers calculate forward only, reverse only, and forward-reverse flow quantities.
Each totaliser uses separate elements to accumulate hour quantity and total quantity to prevent round-off

power supplies

Power Inputs: Internal 12V battery. Connectors for external 12V and 24V DC supplies
Internal Battery: Low cost exchangeable deep discharge 12V 7.5Ah rechargeable battery. One year endurance when operated
at 1 measurement per minute. Weight 2.5 kg
External 12V supply: Connection for external 12V battery pack for extended measurement period
External 24V supply: Connection for external 15-28V power input compatible with all industrial 24V supplies
Battery Charger: Built-in battery charger maintains internal 12V battery using power from external 24V source, enabling
power harvesting for indefinite endurance
Power Supply Monitor: Power monitoring circuits track supply status. Supply voltages and charge currents can be displayed on LCD,
viewed via the UI, stored in the data logger, and used to control switch outputs. Power supply condition
visible on status LED

data logger

File System: Flash file system with 4 Mbyte capacity and data retention of 20 years
File Content: Configurable to record any combination of power supply voltages, battery charge current, level sensor loop
current, level, area, ultrasound signal quality, velocity and flow rate, plus forward, reverse and total flow
Recording Mode: Proprietary data compression algorithm for extended logger capacity and rapid data retrieval
Recording Interval: Configurable from 15 seconds to 1 hour
Data Capacity: Logger holds more than one year of data when recording all available measurements at one minute intervals
Retrieval Time: Less than 15 seconds to retrieve one month’s data recorded at 1 minute intervals. File synchronization
capability for fast update of previously retrieved data files
Retrieved Data Format: Spreadsheet compatible .csv file with country specific caption text and date/time format for analysis and
reports. Flash file image file including complete flowmeter configuration for data archives


Local: RS232 and USB compatible interface with automatic baud rate detection. Supports 1200, 2400, 4800, 9600,
14400, 19200, 38400, 57600 and 115200 baud
Remote: Optional external SDI or MODBUS device
Software: Mainstream Communicator UI software for system configuration, diagnostics, real- time measurement
display and data retrieval. Mainstream Communicator runs on PC platforms under Windows 2000, XP, Vista,
7, 8, 8.1 and 10 with data transmission from device to PC, for data control, processing and export

user interfaces

On/Off Switch: Push to start – push to stop. Requires 10 seconds continuous pressure to switch flowmeter off to prevent
accidental de-activation
Status LED: High intensity flashing LED indicates system operation and battery status without opening enclosure or
entering manhole. LED also indicates activity on communications port
LCD: Two line x 16 character LCD. Automatic activation when integral light sensor detects enclosure is open.
Configurable display sequence includes date, time, and any combination of measurement data. Country
specific caption text and date/time format

measurands units and formats

Power Supply Voltage: V
Signal Quality: %
Linear (pipe & channel dimensions): Selectable from mm, cm, m, in, ft
Level: Selectable from mm, cm, m, in, ft
Area: Selectable from m2, cm2, mm2, in2, ft2
Velocity: Selectable from mm/s, cm/s, m/s, in/s, ft/s, ft/min
Flow Rate: Selectable from l/s, m3/s, ft3/s, igal/s, USG/s, l/min, m3/min, ft3/min, igal/min, USG/min, m3/h, ft3/h,
m3/d, Ml/d
Quantity: Selectable from l, m3, Ml, ft3, igal, USG
Display Format: Independently configurable display format for each measurement. Options are integer, fixed point with 1 to
6 decimal places, and scientific (E-format). Display defaults to scientific format if data cannot be correctly
represented in selected format

switch outputs

Hardware: Two opto-isolated switches rated at 60V ac/dc and 200mA maximum current. Each switch independently
configurable for state output or pulse output operation
State Output: Switch configurable to respond to any item of measured data with separate switch open and switch close
settings to provide hysterisis. Applications include power supply monitoring and control, low ultrasound
signal quality indication and level, velocity and flow alarms
Pulse Output: Switch configurable to generate a 2.5 second duration switch closure to indicate a defined flow quantity.
Applications include sampler control and remote flow totaliser operation

ptx level sensor

Materials: Titanium, acetal and polyurethane
Dimensions: 185 mm long x 17.5 mm diameter
Cable: 8 mm diameter vented polyurethane cable with Kevlar strain cord
Weight: 1 kg including standard 10 m cable length
Level Range: 0 to 2 m working. Maximum 8 m overrange
Resolution: Better than 1 mm
Combined Accuracy: Combined effects of non-linearity, hysterisis and repeatability better than 0.25% best straight line.
Non-linearity and offsets removed by transducer calibration
Environmental Protection: Fully encapsulated to IP68
Operating Temperature: -20°C to 60°C (temperature compensated 2°C to 30°C)

velocity sensor

Materials: Streamlined µPVC moulding and polyurethane cable
Dimensions: 105 mm long x 50 mm wide x 20 mm high
Cable: 8 mm diameter polyurethane cable with Aramid strain cord. Breaking load 45 kg. Minimum static bend
radius 52 mm
Weight: 1 kg including standard 10 m cable length
Maximum Cable Length: 500 m; 300 m for ATEX Zone 0
Environmental Protection: Totally encapsulated to IP68
Operating Temperature: -10°C to 80°C
Minimum Operating Depth: 30 mm

system unit

Materials: Ultra high impact structural copolymer polypropylene
Dimensions: 280 mm wide x 250 mm deep x 125 mm high
Weight: 5 kg with 7.5Ah internal battery installed
Environmental Protection: Enclosure is IP67. Electronic assembly is encapsulated to IP68 and can operate totally submerged with the
enclosure lid open
Operating Temperature: -10°C to 70°C

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Fixed Quick Start Video

Calibration Video

Software Video

User Manual
Data Sheets & Comparison Chart
Support Helpline
Trouble Shooting
Sensor Installation Requirements