Non-Contact Area Velocity Discuss basic open channel flow measurement

Discuss traditional area velocity flow measurement techniques and technologies

Discuss the latest in Non-Contact Area Velocity flow measurement techniques and technologies

Primary Devices

Flumes

Weirs

Level – Flow Conversion

Flow Meters

Bubblers

Ultrasonic

Pressure Sensors

Traditional Open Channel Flow Measurement

Techniques

Flumes - Advantages 5% Accuracy

Traceable

Open Channel Flow

Handbook

Simple level measurement

Accepted measurement

practice

The “standard”

Flumes - Disadvantages Expensive

Primary Device cost

Installation

Impractical

No place to install

Head loss

Debris

Site conditions change

Flow exceeds initial design requirements

Flume designed to handle future flows

Operating in inaccurate flow range

Weirs - Advantages

Simple

Construction

Easy to install

Primary Device cost

Requires level measurement

Weirs - Disadvantages Expensive

Construction/Installation

Primary Device cost

Stainless Steel

Plywood

Head loss

Debris

Submerged Flow Conditions

Need proper hydraulics

Flow

Measurement

Laboratory

The right product for the application

Traditional Doppler Velocity Measurement Q = A x V

A = Pressure

V = Doppler

C

C

B

B

A

A

CROSS SECTION A-A CROSS SECTION B-B CROSS SECTION C-C

Doppler Velocity Measurement Profile

Return Spectrum

24" Pipe 0.25% 1780 gpm 8" 4.507 ft/s

2150 201K01367 v1.12 Probe 203F00288

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

-400 -200 0 200 400 600 800 1000

Frequency

Sig

nal S

trength

CWD Velocity

Measurement

The Doppler Effect Transmitter and receiver moving toward each

other

The Doppler Effect Transmitter and receiver moving away from

each other

Advanced diagnostics provided early warning of

debris issues

Graphical Diagnostics

Velocity Profiling

Historically the only method for flow measurement without a primary device

Manning Formula

Level only measurement

Bubbler

Ultrasonic

Pressure

Area Velocity

More accurate

Surcharge capabilities

Doppler Area Velocity Sensors

Improved reliability

Data quality unknown

Small pipes

Sensor caused obstruction in flow

Debris, hydraulic issues

Contact AV Sensors

Why use a non-contact flow sensor?

Safety

Maintenance

Market Need

Need non-contact area velocity measurement

Needed more accurate non-contact system than basic

ultrasonic

Manning Formula

Accuracy +/- 20% or worse

Could not handle surcharge or submerged conditions

Contact vs Non-Contact…Why? Safety

Cannot get flushed down a sewer pipe if you are not in the sewer.

Confined Space Entry

Permits

Traffic Control

Manpower

Large Pipe

Difficult Installations

Flow Depths greater than 3 ft

Velocity over 3ft/second

Maintenance issues

Silting, debris

Small pipes – <24” Low level flow measurement

Shallow water depths with high velocities

Dollars$$$$$

$500 per site visit

1 per month

Non-Contact Radar Surface Velocity

Uses radar to read surface velocity.

Surface Velocity is then adjusted to

estimate average velocity

Smooth surface

Surface Ripple

from Wind

Electromagnetic Point Velocity Sensor

Submerged Flow Operation

Non-Contact Radar Velocity Flow Systems Non-contact Surface Velocity Measurement Non-contact Ultrasonic Level Measurement Advantages

More accurate than level only devices Above water installation Minimal maintenance Reads extremely clean water

Disadvantages Needs velocity high enough to generate surface waves Dead band in ultrasonic level measurement Surcharge sensor reads point velocity Requires velocity profiling

May not be practical with widely fluctuating flows Storm events

Deadband

Normal Operation — Lower Flows

Non-contact Ultrasonic Surface Velocity

Confined Space Entry Required

Normal Operation — Submerged Flow

Non-Contact Ultrasonic Surface Velocity Non-contact Surface Velocity Measurement

Non-contact Ultrasonic Level Measurement

Advantages More accurate than level only devices

Measures level and velocity in same location

Disadvantages Confined space entry required for both installation and

maintenance.

Requires velocity profiling Needs velocity high enough to generate surface waves

May not be practical with widely fluctuating flows

Storm events

Non-Contact Laser Subsurface Velocity

Non Contact Area Velocity Flow Measurement System

Level Measurement Ultrasonic

Velocity measurement Laser

Theory of operation

34

LaserFlow Sensor

Return Doppler Signal Light

Flowing Water Stream

V

Below Surface

Theory of Operation Below the surface

5000 Spectral Velocity Readings

Point of Convergence

Ultrasonic Level Measurement

Laser Velocity Measurement

Multipoint -Multidepth

Velocity Method

Multipoint – Multidepth Velocity Method

Normal Operation Ultrasonic

Level (USLS)

Laser velocity

Submerged Condition Begins

LaserFlow Fully Submerged

CWD sensor reading velocity

Pressure Sensor reading depth

Non-contact Laser Sub-surface Velocity

Non-contact Sub-surface Velocity Measurement

Non-contact Ultrasonic Level Measurement

Advantages More accurate than level only devices

Reads below the surface velocity using laser

No profiling required under normal flow conditions

Disadvantages

Extreme velocity changes could requires velocity profiling

Steam or heavy foam may not work

Permanent Wall Mount

Temporary Mount

Street Level Tool

Street Level

Installation Tool

Sensor Mounted

Repeatable Data

Ultrasonic Signal Strength

Returned Laser Signal Power

Diagnostic Data

Non-Contact Applications Collection System Monitoring

Permanent AC powered Billing

Portable DC powered Inflow and Infiltration

WWTP Influent and effluent In plant pipes and channels

Hydraulic Modeling Accuracy

Industrial monitoring Harsh Chemicals / Environments

Storm water Large debris

Harsh Chemical Environment

Storm sewer

Submerged flume condition

Submerged flume condition Bubbler

Ultrasonic

“Not” Non-Contact Applications Non uniform hydraulics

Weir walls

Heavy Foam

Major temperature swing environments

See only surface or limited below the surface

Severe bends in manhole

Dynamic IP

FL Client FL Client

FL Client FL Client

Off-site User

Off-site User

Remote Sites

Firewall

Static IP

Windows Server • Server Software

• IP Listener

• Web UI

• Alarm Server

• Enterprise Database

• MS SQL or Oracle

Organization Network

Dynamic IP

FL Client FL Client

FL Client FL Client

Off-site User

Off-site User

Remote Sites

Firewall

Static IP

Windows Server • Server Software

• IP Listener

• Web UI

• Alarm Server

• Enterprise Database

• MS SQL or Oracle

Organization Network

Dynamic IP

FL Client FL Client

FL Client FL Client

Off-site User

Off-site User

Remote Sites

Firewall

Static IP

Windows Server • Server Software

• IP Listener

• Alarm Server

• Web UI

• Enterprise Database

• MS SQL or Oracle

Organization Network

Dynamic IP

FL Client FL Client

FL Client FL Client

Off-site User

Network Connection

(e.g. VPN)

Off-site User

Remote Sites

Firewall

Static IP

Windows Server • Server Software

• IP Listener

• Alarm Server

• Web UI

• Enterprise Database

• MS SQL or Oracle

Organization Network

Dynamic IP

FL Client FL Client

FL Client FL Client

Off-site User

Remote Sites

Firewall

Static IP

Windows Server • Server Software

• IP Listener

• Alarm Server

• Web UI

• Enterprise Database

• MS SQL or Oracle

Organization Network Off-site User

via Web Browser

Whip Style

Manhole Antenna

Blade Antenna

Summary

Non-Contact Area Velocity More accurate than traditional non-contact level

only devices

Precise and accurate

Reasonably priced

Easy to install and maintain

Safety for personnel

Minimal maintenance

Flexible Platform Multi-sensor design

Internet access to data

Questions?