Débitmètre portable à effet Doppler (Model PDFM-IV)
Fabricant: Greyline
- Strap-on Ultrasonic Sensor - Internal Battery and/or AC Powered - Fast, Easy Operation - Built-in 3-Key Calibrator - Programmable Totalizer - 50,000 point Data Logger - RS232 Serial Output and Windows software - 4-20mA Output - Adjustable Sensitivity
PDFM-IV Portable Doppler Flow Meter
It's ideal for flow troubleshooting, balancing and checking performance of permanent flow meters. The new PDFM-IV is fast and easy to operate – you can mount the sensor on the outside a pipe in less than a minute. Use the built-in keypad and calibration menu to set up the flowmeter for your application. The PDFM-IV works on any liquid containing bubbles or solids and is recommended for "difficult liquids" like wastewater, slurries, sludge, chemicals, viscous liquids and abrasives. Measures flow through most metal and plastic pipes including PVC, ductile iron, carbon steel and stainless steel.
The Greyline PDFM-IV is AC/DC powered with a built-in battery and charger. With its 4-20mA output you can even use the PDFM-IV as a spare transmitter in critical applications. For flow studies and troubleshooting use the built-in 50,000 point Data Logger. Retrieve data logs with 'Greyline Logger' software – included free with each PDFM-IV. Connect the RS232 output directly to the serial port on your PC or Laptop, or by dial-up connection through modems and phone lines.
New!
Store and Retrieve Flow or Level data with this built-in Data Logger
Displays Logs in Graph and Table format with your choice of engineering units
Exports data to Spreadsheet or Database programs
Greyline Data Logger Features:
50,000 date and time-stamped data point capacity
Multi session capability - stores up to 10 separate logging "sessions"
Includes "Greyline Logger" software for Windows™
Isolated RS232 serial output with selectable baud rates from 1200 to 19,200
Retrieve Data Logs by modem or by direct PC connection
Log Flow or Level values from 1 second to 30 minute intervals
Log reports including Minimum, Maximum, Average and Total in your choice of 1-24 hour intervals
Each Greyline Instrument with built-in Data Logger includes an isolated RS232 serial output, terminal connections, cable and adapters. Connect directly to the serial port on your PC or Laptop, or by dial-up connection through modems and phone lines.
Run the Greyline Logger software program to retrieve and display data logs on your computer. Display multiple files or "sessions" in both graph and table formats. Log files can be exported in graphic file formats or as delimited text files for use in spreadsheet or database programs.
Greyline Logger softwareruns on any PC with Windows 95, 98 or NT.
Greyline ultrasonic sensors are mounted at the top of a tank or in a position above the liquid being measured. The sensor continuously transmits pulses of high frequency sound (typically 42 kHz) which travel away from the sensor, hit the surface of the liquid and return to the sensor.
The instrument electronics measure the time it takes from transmitted sound to return of the echo. With reference to the speed of sound in air, the exact distance of the liquid surface from the sensor can be calculated with high accuracy (±0.25% of maximum range).
Since the speed of sound is affected by air temperature, Greyline ultrasonic level sensors include a built-in temperature sensor. Level/distance measurements are automatically temperature compensated throughout the operating temperature range of the sensor.
The sensor should be positioned so that it has an clear "view" of the liquid surface and away from ladders, pipes or other obstructions. Greyline recommends 1 ft. from the sidewall for every 10 ft. depth (300 mm for every 3 m depth). False echoes from agitators (sweeping under the sensor), turbulence and waves can be filtered and disregarded by the instrument.
Greyline models range from simple 4-20mA level indicating transmitters, to sophisticated monitoring, controlling and logging models.
The common method of measuring flow through an open channel is to measure the height or HEAD of the liquid as it passes over an obstruction (a flume or weir) in the channel. Using ultrasonic level technology, Greyline open channel flow meters include a non-contacting sensor mounted above the flume or weir. By measuring the time from transmission of an ultrasonic pulse to receipt of an echo, the water level or "Head" is accurately measured.
Flumes and weirs are specially designed channel shapes that characterize the flow of water. Common types are Rectangular Weirs, V-Notch Weirs, Parshall flumes and Palmer Bowlus flumes. The choice of flume or weir type depends on the application: flow rate, channel shape and solids content of the water. Contact Alpha Controls for advice on selection of a suitable flume or weir for your application.
Greyline open channel flow meters can be calibrated to any flume or weir by menu selection. The open channel flow meter electronics use an internal formula to calculate flow rate (Flow = K Hn, where 'K' and 'n' are constants and 'H' is Head as measured by the instrument). Calibration to uncommon or custom flumes can be done by direct entry of 'K' and 'n' constants. Greyline also offers a PC software program "Find K&n" to develop calibration constants from a flume or weir flow chart.
Greyline open channel flow meters include a non-contacting ultrasonic sensor, connecting cable and an electronics enclosure which can be mounted at a convenient location nearby (within 500 ft / 152 m). Sensors can be rated intrinsically safe for mounting in hazardous-rated locations. The instruments display, totalize, transmit and control, and some models include data logging/flow reporting systems.
Doppler flow meters measure flow from outside a pipe with a strap-on sensor. Greyline Doppler meters continuously transmit high frequency sound (640 kHz) that travels through the pipe wall and into the flowing liquid. Sound is reflected back to the sensor from solids or bubbles in the fluid. If the fluid is in motion, the echoes return at an altered frequency proportionate to flow velocity. Doppler flow meters continuously measure this frequency shift to calculate flow.
The Doppler effect was first documented in 1842 by Christian Doppler, an Austrian physicist. We hear everyday examples of Doppler: the sound of a train whistle changing pitch as it passes by, or the exhaust noise from a race car as it speeds past our location.
The Doppler technique only works on liquids which contain solids or gas bubbles to reflect its signal. These are "difficult" liquids that may damage regular flow meters: slurries, sludge, wastewater, abrasives, viscous and corrosive chemicals. Because the sensor mounts on the outside of the pipe, there is no pressure drop and no obstruction to flow.
For best performance Doppler sensors should be mounted away from turbulence creating devices like pipe elbows and tees, and away from velocity increasing devices like controlling valves and pumps. Typical accuracy is ±2% of full scale.
Doppler instruments include a strap-on sensor, connecting cable and an electronics enclosure which can be mounted at a convenient location nearby (within 500 ft / 152 m). Sensors can be rated intrinsically safe for mounting in hazardous-rated locations.
Greyline PDFM-IV Portable Doppler Flow Meter
Standard features include:
sensor - strap-on, single head ultrasonic for 1/2" - 180" (12.5 mm - 4.5 m) ID pipes
sensor cable - 12ft / 3.5m shielded coaxial pair
installation - sensor coupling compound and stainless steel Sensor mounting clamp for 0.6 - 32 in. (15-800 mm) OD pipes
enclosure - portable, aluminum (non-rated) in foam lined Cordura™ carry-case
sensitivity - keypad adjustable with signal strength indication
power input - built-in battery with internal charger - switch select 100-160VAC 50/60Hz or 200-260VAC 50/60Hz - 12 VDC (from external battery)
outputs - 4-20mA, RS232C with programmable baud rates up to 19,200
data logger - 50,000 point with multi-session and flow report capability
PC software for data log retrieval by direct serial connection, or by dial-up connection with modems and telephone lines
1 set cables and plugs - AC power, 4-20mA, 12VDC, RS232
1 manual
PORTABLE DOPPLER FLOW METER SPECIFICATIONS
SCOPE: This specification covers a portable, ultrasonic Doppler-type flow meter as manufactured by Greyline Instruments, Massena, New York / Long Sault, Ontario. This instrument shall provide for non-intrusive flow measurement, indication, totalizing and transmitting of the flow rate in a full pipe.
GENERAL:
Each portable Doppler flow meter shall have the following design features and engineering specifications:
A. PERFORMANCE SPECIFICATIONS
Have an accuracy of ±2% of full scale on most wastewater applications. Have linearity of ±0.5% and repeatability of ±0.1%.
Operate on liquids with entrained particles or gases of 100 microns or larger and minimum concentrations of 75 ppm.
Operate on the following pipe materials: carbon steel, stainless steel, ductile iron, copper, PVC, FRP, ABS and other selected engineering materials.
Operate on AC/DC power. Include an internal 12VDC gel type rechargeable battery with minimum capacity for 16 hours continuous battery operation. Recharge and operate with power input of 100-160VAC and 200-260VAC 50-60Hz, and 12VDC.
B. TRANSDUCER
Have a single-head, strap-on transducer with twin piezo-electric ceramic transmit and receive crystals encapsulated in epoxy resin and a stainless steel housing.
The transducer shall be solid state and transformer isolated, and designed to meet intrinsic-safe requirements.
The transducer shall be waterproof and operate continuously at temperatures from -10°F to 200°F (-23°C to 93°C), and withstand accidental submersion to 10 psi.
The transducer shall be designed to install on pipes with inside diameter ranging from 1/2" to 180" (12.5 mm to 4.5 m).
Have a 12 ft (3.6 m) long flexible, shielded coaxial pair cable extending from the transducer to the electronics.
Shall include Manufacturer's recommended sensor coupling compound and adjustable stainless steel sensor mounting clamp.
C. ELECTRONICS
Have a portable aluminum enclosure in a padded Cordura™ carrying case with shoulder strap. Total weight shall be less than 10 lbs. (4.5 kg).
Electronics shall be designed for continuous operation at temperatures from -10° to 140°F (-23° to 60° C).
Have a built-in 3-key calibrator with operator selection of parameters through visual prompts from a Menu calibration system. Systems requiring calibration by Parameter codes, BCD switches or external calibrators shall not be accepted.
Have a continuous 4-digit LCD display indicating flow in user-selected engineering units. Have a 16-digit alphanumeric display indicating totalized flow, units of calibration, and/or signal strength.
Have flow proportional 4-20mA output rated to maximum resistive load of 500 ohms.
Have a built-in 50,000 point data logger, RS232C serial output and connecting cables. Data logger shall support time and date-stamped logging and generate formatted flow reports including total, average, minimum, maximum and times of occurrence.
Include Windows software for data log retrieval, graphing and export.
Have keypad adjustable sensitivity which modifies the received signal strength to reduce interference. Have automatic signal strength monitoring to drive the flow reading to zero at low signal threshold.
Have a battery status indicator with automatic low battery shut off and battery overcharge protection.
D. OPTIONAL FEATURES FOR INSERTION IN SPECIFICATION AS REQUIRED:
Have a High Temperature Sensor for operating temperatures from -40° to 302°F (-40° to 150°C).
Include additional 150 g. manufacturer's recommended ultrasonic sensor coupling compound.
Include 50 ft (15 m) length Sensor Cable extension complete with connecting plugs.
E. MANUFACTURER
The instrument shall be a Model PDFM-IV Portable Doppler Flow Meter as manufactured by Greyline Instruments Inc., and warranted against defects in materials and workmanship for one year.
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