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 81 BLEACHERY COURT     WARWICK   RI   USA    02886     401-463-9199
The Leader in Reliable Flow Measurement
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Open Channel Flow Measurement

If the EPA or other authorities
question your wastewater
discharge measurement,

PRIMARY FLOW SIGNAL, INC.
has the answer!

THE HALMI-PARSHALL FLUME WAS SPECIFICALLY DEVELOPED TO SUIT SUCH NEEDS, WITH:

point.jpg (619 bytes)+/- 2% ACCURACY
(+/-0.75% with Flow
Calibration)

point.jpg (619 bytes)ACCURACY TRACEABLE
(to NIST formerly NBS)

point.jpg (619 bytes)LOW HEADLOSS

point.jpg (619 bytes)ADJUSTABLE LAYING
LENGTH


point.jpg (619 bytes)FOR ANY PIPE LINE SIZE

point.jpg (619 bytes)REMOVABLE
RESTRICTORS

provide adjustable flow
meter capacity


REMOVABLE
RESTRICTORS

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point.jpg (619 bytes)ACCURACY CAN BE
VERIFIED
visually in the field

point.jpg (619 bytes)PFS DESIGN SERVICE
WILL
properly locate the
meter

point.jpg (619 bytes)METER CAN BE BUILT OF ANY MATERIAL required
by the specific application

point.jpg (619 bytes)ANY SIGNAL SENSOR
CAN BE USED
INCLUDING:

C/R Probe; Staff Gauge;
Ultrasonic Level Measurement;
Float Well; Pressure
Transmitter;
SPECIAL PATENTED design
US Patent No: 4671119

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THE Halmi- Parshall METERING PRINCIPLE
LEAVES NO QUESTION UNANSWERED!

 
Have you ever specified or used Parshall Flumes in the
Pipe-to-Box-to-Flume-to-
Box-to-Pipe”
way shown here?
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Have you ever considered the errors
this design introduced?

Flow calibrations performed at the Alden Research Laboratory reveal that the customary “pipe-to-box-to-flume-to-box-to-pipe” design
introduces the flow metering errors shown to the left (of this paragraphs) and greater ones, depending on the geometry of the metering section.
Halmi-Parshall Flume meters eliminate these errors.

Additional advantages of
the PFS-Halmi-Parshall
Flume design are:

- Lower Headloss
- Shorter laying length
- Maintains accuracy regardless of line size.
- Accepts different inlet and outlet pipe             diameters without accuracy deterioration.
- Adjustable capacity using removable restrictors.

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The Main Difference lies in the
INSTALLATION DESIGN SERVICE

Which is part of the metering package supplied by PFS, Inc.
The importance of this service is underscored by the fact that the placement of a flume in the pipe line and the geometry and slope of the upstream and downstream piping play an important role in securing accurate flow measurement.

This kind of design service is unavailable from the “pipe-to-box-to-flume-to-box-to-pipe” design manufacturers. When these manufacturers are approached with placement questions, they disclaim responsibility for the accuracy of the installed meter. Instead, they refer customers to standard published Parshall flume literature, implying that the flumes
described therein are identical to those they are selling. This implication is far from the truth, as proved by the errors uncovered through PFS, Inc. research work (see PFS Publication No: 820-A.) In contrast, PFS, inc. takes full responsibility for the PFS-HF and PFS-HN design.

DIMENSIONS - CAPACITIES - INSTALLATION

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Please send comments, questions, or suggestions about our services to Dezi G. Halmi at dezi@primaryflowsignal.com
Send comments or inquiries about this site to  Dezi@primaryflowsignal.com
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Copyright 2001 by PFS, Inc
Web Services by Primary Flow Signal, Inc.
Last Modified 17 May 1999