Greyline Instruments DFM-6.1 Data sheet

Easy to Use, Non-Contacting Flow Meter

for Accurate Flow Measurement of “Difficult” Fluids from Outside a Pipe

Doppler

Flow Meter

Model DFM 6.1

Displays, Transmits

Totalizes and Controls

Backlit LCD

Simple 5-Key Calibration

Password Protected

4-20mA / 0-5V Output

128 MB Data Logger

Modbus ® or HART Optional

Ideal for “Difficult Liquids”

External Sensor

No Contact, No Maintenance

Non-Contacting Flow Measurement and Control

Ultrasonic Sensor mounts on any Pipe

Greyline Doppler Flow Meters monitor the flow rate of dirty or
aerated liquids including: wastewater, sewage, slurries, abrasives,
and viscous liquids. Recommended for full pipes and any fluid that
contains solids or bubbles.

The DFM 6.1 clamp-on sensor is mounted on the outside of any
pipe ½ inch / 12.7mm diameter or larger. To measure velocity an
acoustic signal is reflected back to the sensor from moving particles
or gas bubbles suspended in the fluid. Flow is calculated based on
configured pipe ID.

Installation is easy - without shutting down the flow system. No
contact is made with the moving fluid and no pipe cutting or drilling
is required. There is no fouling or scale build-up on the sensor.

The DFM 6.1 Doppler Flow Meter includes an ultrasonic sensor, an
easy to use 5-key calibration system, a large digital flow rate
display with totalizer, isolated 4-20mA output, 26 million point data
logger, and two programmable control relays. The sensor is
classified as non-incendive and an intrinsically safe sensor is
optional.

Non-Contacting Doppler Flow Meter

Measures Flow with Clamp-On Ultrasonic Sensor

Designed for “difficult” liquids

The DFM 6.1 Doppler flow meter works best in applications that would defeat regular contacting flow
meters. Because the Sensor is mounted on the outside of the pipe, it is unaffected by abrasives or
harsh fluids. There is no obstruction to flow and no pressure drop.

Enhanced Signal Processing and Industrial Noise Immunity for Reliable Accuracy

The DFM 6.1 Doppler flow algorithm filters out background noise and interference. The high speed digital signal
processor discriminates against weak and distorted signals for increased reliability and accuracy.

Easy to Install

Each DFM 6.1 Doppler Flow Meter includes a clamp-on ultrasonic sensor, an
adjustable stainless steel mounting clamp and sensor coupling compound.
The sensor fits on the outside of any pipe diameter ½" (12.7 mm) or larger. It
takes just a few minutes to install. There is no need to shut down flow.

Simple, Single-Head Sensor design

Ultrasonic signals are transmitted and received from a single-head sensor.
The mounting clamp (included) ensures correct sensor alignment on
horizontal or vertical pipes. The DFM 6.1 automatically self-tunes to the cable
length up to 500 ft.(152 m).

Works on most Pipes

The Greyline DFM 6.1 Flow Meter measures flow in PVC, carbon steel,
stainless steel, cast iron, HDPE ductile
iron, and concrete lined ductile iron... any

pipe material that conducts ultrasound.
Doppler signals cannot transmit through pipe walls which contain air pockets (e.g.
concrete or wood), or loose pipe liners (with an air gap between the liner and pipe
wall).

Backlit Display with Easy to Use, 5-key Menu System

Configuration is easy with the new DFM 6.1 user-friendly menu system. Press the
arrow keys to scroll through menus, change settings and enter calibration values.
You can select English, French or Spanish menus, enable a password to protect
settings and control brightness of the digital display.

Reverse Flow Measurement

The DFM 6.1 measures flow in either direction and displays positive or negative
values. You can control the Totalizer to subtract reverse flow, or to totalize forward

flow only. The 4mA setting can
also be adjusted to a negative flow setting.

SENSO R

26 Million Point Data Logger

BUBB LES OR SOL IDS
REFL ECT SOUND

SOUN D WAVES
REFL ECTED
BACK TO SENSOR

SOUN D WAVE
TRAN SMITTED
FROM SENSOR

The DFM 6.1 Doppler Flow Meter comes standard with a built-in 26
million point data logger. It includes Windows software to display flow
charts and tables, and to create dynamic flow reports. Just plug in a
standard USB flash drive and log files are downloaded automatically.

Principle of Operation

The DFM 6.1 Sensor transmits continuous high frequency sound through the pipe wall into the flowing liquid.

Sound is reflected back to the Sensor from particles or gas bubbles in the liquid. If the liquid is flowing, the reflected sound
returns at an altered frequency (the Doppler effect). The DFM 6.1 continuously measures this frequency shift to accurately
measure velocity.