Omega Products FMA-5606 Installation Manual

OMEGA

ENGINEERING, INC.

oium

Al

Behmdogks

FMA-5000 SERIES
Electronic Mass
Flowmeters

CompIqy

Operator’s Manual

OMEGAwanamsVlisun~~obeheeddetedsinmaterialsandwakmanshl~andtogivesatlsfactoryseMcefapenod
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SECTION 1

1.1

General Description

TABLE OF CONTENTS

FMA-5000 Series

INTRODUCTION

.

2

. . . . . . . . . . . . . . . . . .

.

2

. . . . . . . . . . . . . . . . .

SECTION

2.1

2.2

2.3

2.4

2.4.1

2 .4 .2

SECTION 3 OPERATION.

3.1

3.2

3.3

SECTION 4 MAINTENANCE

4.1

4.1.1

4.1.2

4.1.3

SECTION 5

5.1

5.2

5.3

2 INSTALLATION. . . . . . . . . . . . . . . . . . . . . . 2

Unpacking
Mechanical Installation
Transducer Connections
Electrical Connections
g-Pin
OEM Electrical Connections

...........................

...................

..................

...................

“D” Connector Pin Assignments

...............

........

........................

Operating Instructions
Notes to Operating Instructions
Principle of Operation

...........................

.....................

........................... .

.....................

Flow Path Cleaning

Inlet and Outlet Screen
Laminar Flow Element
Sensor Tube

FLOW CALIBRATION

General Calibration Procedure
Recalibration over the Same Flow Range
Flow Calibration Over a Different Flow Range and/or Gas

.............................

..........................

(LFE)

........................

.................................

......................

..................

...............

....

SECTION 6 TROUBLESHOOTING. ................ .

6.1

6.2

General......................................1 6

Troubleshooting Guide

...........................

.

.

.

.
.

,12

.12
.12

.13

.14

.16

2
3

3
4
4

6

7

7

7

9

12

14
14
15

16

SECTION 7 SPECIFICATIONS
APPENDICES

1.

2.

3.

4.

Exploded View of Transducer and Parts List
Electrical Schematics
Conversion of Flow Rate
KFactors

............................... .

............................

....................................

....................

.........................

............

.17

..19

.20

.21

.22

.23

QUICK OPERATING INSTRUCTIONS

Section 3 for Detailed Operating Instructions)

(See

1.

Install the FMA-5000 Series into the gas flow line. Note the flow

direction arrow on the flowmeter. If you are using

a good quality paste pipe thread sealant for sealing and tighten
one-and-one-half turns only. Do not overtighten.

%

inch pipe, use

I&

.’

II

Overtightening may crack the fittings or shift
calibration.

The line pressure and temperature

(5OY).

150°F

2.

Apply power to the flowmeter. If you are using the FMA-PST

should

not exceed 150 psig

or

Power Supply, just plug the power supply into line power and the
connector into the input power jack on the side of the flowmeter.
If you are providing your own power, use 12 to 15 VDC at 100

mA

maximum. 24 VDC operation is made possible by removing the

0 ohm resistor in the R-10 location and replacing it with a 160

%

watt resistor. The resistor will not fit between the D con-

ohm
nector and DC power jack, so stand it off from the PCB. This is
acceptable since it gets hot in normal operation. Do not supply

+DC power at the D connector while using an FMA-PST power

supply at the DC power jack. The D connector

pinout

is shown

in Section 2.4.

3.

Allow at least 15 minutes for warm-up

4.

After the warm-up period, the flowmeter is monitoring the gas
mass flow rate

5.

Output Signals: The output signal of the flowmeter is either O-5

mA

VDC (standard) or 4-20

(optional). The output is linearly pro-
portional to the gas mass flow rate. The full scale range and gas
are shown on the front label. Section 2.4 describes the electrical
output signal hookup For example, if you have a O-5 VDC output
signal, 5.00 VDC is the output signal for the full scale listed on the
label; 2.50 VDC is for one-half of full scale, and 0.00 VDC is for

mA

zero flow. On the other hand, if you have 4-20

mA

20.00

one-half of full scale, and 4.00

6.

FMA-5000 Series with Integral or Remote Display: The

is the output signal for the full scale; 12.00

mA

is for zero flow.

output signal,

mA

is for

3% digit
LCD reads directly in engineering units or percent of full scale The
full scale range and gas are shown on the front label. The decimal

point for the flow rate is set at the factory and will show

automatically (e.g., 5.54

SLM

or

76.4%).

SECTION 1 INTRODUCTION

1.1

GENERAL DESCRIPTION
The OMEGA@ FMA-5000 Series Electronic Mass Flowmeters

measure the mass flow rate of gases in 13 ranges
(standard cubic centimeters per minute), to 040 SLM (standard liters

per minute). Their analog output, integral/remote digital display, in-
sensitivity to temperature and pressure variations, and low cost make
them ideal substitutes for rotameters, and they can also be used to
calibrate rotameters. Other applications include chemical and food
processing, gas chromatography, and leak and filter testing to name
a few.

The FMA-5000 Series are available with or without a digital display.

tiltable

The display is
with 25 feet of cable for remote surface mounting. The flowmeters
require a 14 to 24 VDC external power source that can be provided
by the optional Model FMA-PST Power Supply. A O-5 VDC (standard)
or 4-20
flow rate is provided for recording, datalogging, or control. A

“D” subconnector for the output signal, input power, and remote
display drive is supplied with its mating connector for all FMA-5000
Series units.

All wetted surfaces are constructed of corrosion-resistant glass- filled
nylon plastic,
commodates almost any gas including air, oxygen, process gases,
and even corrosives.

(optional) output signal linearly proportional to gas mass

mA

over

316SS.

and Viton O-rings. This rugged construction ac-

fromO-10

180° for easy viewing and can be ordered

SCCM

g-pin

SECTION 2 INSTALLATION

2.1

UNPACKING
Remove the packing list and verify that all equipment has been receiv-

ed. If there are any questions about the shipment, please call OMEGA

Customer Service Department at [phone].
Upon receipt of the shipment, inspect the container and equipment

for any signs of damage Take particular note of any evidence of rough
handling in transit. Immediately report any damage to the shipping
agent.

The carrier will not honor any claims unless all shipping
material is saved for their examination. After examining and
removing contents, save packing material and carton in the

event reshipment is necessary.

NOTE

2

2.2

MECHANICAL INSTALLATION

-1

The maximum pressure and temperature

in

the flow line in

which the flowmeter is to be installed should not exceed

(5OOC).

150 psig

In order to

kg/cm2

gage) or

(10

enstire

a successful installation, inlet and outlet tubing or

150°F

piping should be in a clean state prior to installing the flowmeter in-
to the system. The FMA-5000 Series is applicable to clean gas only
because

particulates

tube and laminar flow element over a period of time.

and other foreign matter may clog the sensor

If the gas con-

tains particulate matter, install a high- efficiency, 50 to 100 micron,
in-line filter upstream of the flowmeter.

Do not locate the flowmeter in areas subject to sudden temperature
changes, moisture, or near equipment radiating significant amounts
of heat. Allow adequate space for cable connectors and wiring. Be
sure the arrow on the side of the transducer points in the direction
of flow. If the unit is to be mounted in other than a horizontal posi-
tion, the zero will need adjustment. Refer to Section 5.2.

The flowmeter may be mounted to a chassis with two 6-32 self- tap-
ping screws. Refer to Figure 2-l.

2.3

TRANSDUCER CONNECTIONS
The transducers are supplied with either% inch female NPT (stan-

dard) or

%

inch inlet and outlet fittings. These fittings should not be

removed unless the flowmeter is being cleaned or calibrated for a new

%

flow range VCO or VCR fittings are available on special order.

inch
pipe requires a good quality paste pipe thread sealant and should be
installed in the inlet and outlet fittings 1% turns beyond hand-tight.

Ovettightening may crack the fittings or shift
calibration.

%

For the first installation of

inch (outside diameter) fittings, insert
the tubing into the fitting. Make sure that the tubing rests firmly on
the shoulder of the fitting and that the nut is finger-tight. Scribe the
nut at the 6 o ’clock position. While holding the fitting body steady

the

with a back-up wrench, tighten

nut 1% turns, watching the scribe

mark make one complete revolution and continue to the 9 o ’clock

position. After this, the fitting can be reconnected by snugging with

a wrench. Do not fail to use a back-up wrench or the inlet fitting may
be damaged. Do not mix or interchange parts of tube fittings made
by different manufacturers.

Finally, check the system’s entire flow path thoroughly for leaks
before proceeding to Section 3, Operation.

4.16

(WITHOUT

DISPLAY)

SIDE VIEW

-.

6.66

__

END VIEW

~-

~-

ALL

DIMENSIONS IN INCHES

0.125 DIA. THRU PANEL-2 PLACES.:

PANEL MOUNTING HOLES

ALL DIMENSIONS IN INCHES

BOTTOM VIEW

‘-

6-32 X 0.15 DP.

(SELF TAPPING)

2.4

2.4.1

2-l.

Dimensions

Figure

ELECTRICAL CONNECTIONS
g-Pin

D Connector Pin Assignments

+15 VDC power supply

The flowmeter requires a single
capable of providing a minimum current of 100
configured for

+24

VDC power at 100

is via either the DC power jack or the

+12 to

mA,

and can also be

mA.

Operating power input

g-pin

D connector on the side
of the enclosure. The pin numbers for this D connector are shown in
Figure 2-2 and the pin assignments are given in Table 2-1. The out-

g-pin

put signal is obtained from the

D connector. A O-5 VDC out-

put signal linearly proportional to gas mass flow rate is standard. A

mA

4-20

current loop signal is optionally available.

When the flowmeter is configured for a remote display, connections
are made

D connector. Power connections for the display and

via the

transducer are shared in this mode unless the optional power supp-
ly is used.

4

Figure 2-2. D Connector and DC Power Jack

The following connection points can be made through the D connec-
tor or, in OEM applications, made through the circuit board solder pad
connections. The display pad connections are shown for applications
requiring remote mounting of the digital display. The letters appear
on the display circuit board and are shown in Figure 2-3.

PIN NO.

1
2 Signal Common
3
4
5
6
7 Power Common
8
9 4 to 20

FUNCTION DISPLAY PAD
No Connection

N/A
N/A

+

5 VDC Flow Signal

0 to

Supply (12 or 24

VDCl+Power
Remote Display Flow Signal
Remote Display Reference

N/A
(A)

0)
(Cl
(B)

4 to 20

mA

Return (Common)

mA Output

N/A
N/A

Note that the numbers on the connector plug may not agree with the
numbering system as it appears in Figure 2-2. It is important to make
sure that the proper wires are in the proper location.

NOTES

g-pin

Remote display connects through the

D connector
only. The pads A-D in the top right of the main circuit
board are for integral display mounting only.

Power supply voltage must be specified at time
Operating a 12

VDC meter at 24 VDC will cause damage.

of

order.

Running a 24 VDC meter at 12 VDC will result in faulty
operation.
Do not supply +DC power at the D connector while
using an FMA-PST power supply at the DC power jack.
Both supplies may be damaged.

,

‘ FO R

DIGITAL
DISPLAY

“D”

CONNECTOR

Sdder Pad Assignments

Figure 2-3.

2.4.2

OEM Electrical Connections

-

PCB

FOR

Input/Output

One special design OEM version transducer has an electrical port

(hole) on its side for electrical input/outputs. This port is just above the
input power jack (see the exploded view, item 27, in Appendix 11.
Wires entering via this port are soldered to the printed circuit board
as shown in Figure 2-3. The solder pad assignments are given in Table
2-l.

PC6

To gain access to the

to make the solder connections for special
design applications, refer to the exploded view in Appendix 1 and
follow these steps.

6

1.

If the flo wme ter has the digital display:

fro m

F irst, re m ove the

(al

rotating the display
tinue to rotate until this lever-ar m action snaps out the two
yokes holding the display (No. 30). Use extra caution during
this operation as excessive force will break the delicate wire
connections. Carefully m ove the display asse m bly to expose
the
ert excessive force on the display while rotating, as doing so
could crack the LCD display.
Next, re m ove the two screws

(b)

351
enclosure (No.
The top, front and back sides of the enclosure can now be

(cl

re m oved
to the flo w pa th), exposing the PCB.

2. If the flo wme ter does not have the digital display:
(al

Remove the label (No.
expose the two screws.

(b)

Then follow steps lb and

To reasse mb le, reverse this process.

For applications requiring flow totalization or alar m s, it is possible to
connect the F MA -5000 Series to the O MEGA FMA -DV Series elec-
tronics. Contact O MEGA Sa les Depart m ent for special applications.

Zrews

two

and the two screws (also No.

(the

display

until.it

securing the display base

10).

front slides out towards you and perpendicular

291

t he transducer by carefully

hits the top plate and slowly con-

35).

Do not ex-

(No.

21)

in the display base (No.(Na

21)

i n the back o f t he

fro m the plain top cover (No. 281 to

lc above.

SECT ION 3 OPERAT ION

3.1

3.2

QU ICK OPERAT ING INSTRUCT IONS
Qu ick operating instructions are given on the first page of this

m anual.

OPERAT ING NOTES

1. Referencing the Flow Rate to Other Te m perature and Pressure
Conditions

The gas flow rate output of the flow m eter is referenced to standard

(7 OOF )

cond iti ons of

unless you have specified otherwise in your order. Be sure you know

the reference conditions of your unit, because it m ay m ake a dif-

ference if you are co mpa ri ng the ou tpu t w it h ano ther type of
flo wme ter. For exa m ple, the output reading of the F MA -5000 Series
w ill be approxi m ately 7 % lo wer if it is referenced to

‘X. Appendix 3 shows how to convert the flow rate output of your

21
instru m ent to other standard conditions and how to find the flow rate
referenced to the actual te m perature and pressure conditions in the

pipe.

21°C

and 760 mm o f m ercury

7

at mospherel.

(1

O°C

rather than

2. Accuracy
The standard accuracy is

*2%

of full scale. A

51% accuracy is

available with special calibration or upon recalibration (See Section

5.2). The

signal is accurate to within

curate to within
signal for zero flow can be as much as
note if

rt2% of full scale accuracy means the O-5 VDC output

mA

kO.1

VDC, and the 4-20

mA.

kO.4

you

get an output signal at zero flow (as long as it is within

This means, for example, that the output

kO.1

VDC or

output is ac-

*0.4mA.

Please

either of these two ranges), it does not mean the flowmeter is
malfunctioning. For models with the digital readout, the accuracy is
simply 2% times the full scale flow rate listed on the front label. For
example, if your full scale is 10 SLM, the digital readout will be ac-
curate to
as

kO.2 SLM, and the reading at zero flow may be as much

-+0.2

SLM and still be within the stated accuracy specification.

3. Overranging

If the flow rate exceeds the full scale range listed on the front label,
the output signal and digital display (if you have it) will read a higher
value.

The FMA-5000 Series has not been calibrated for overranged flows
and probably will be both non-linear and inaccurate. If the supply
voltage is only 12 VDC, the overranged reading may only exceed the
full scale reading by 10% maximum. If the supply voltage is higher,
such as with the 24 VDC option, then the output can exceed full
scale by as much as

50%, or more. If you have the digital display, the

display cannot exceed the four digits 1999. If the flow rate exceeds

1999, the right-most digits will blank and only the left-hand “1” will

appear on the display.

Due to the operating principle of the sensor, if the flow overranges,
the output will become nonlinear and at some point will go “over the
hump”. After this point, the output signal will decrease even though
the flow is increasing. This will not cause any damage and will cor-
rect itself, usually within 30 seconds after the flow is shut off or
returns to within the calibrated range of the meter. In systems where
it is possible for overrange conditions to occur, it is recommended that
a valve or critical orifice be inserted in the line to limit the flow to ap-
proximately 25% above the full scale range.

mA

4. Optional 4-20

mA

The 4-20

output signal current flows from the 4-20

pin on the D connector through the load

Output Signal

mA

output

(50 to 500 ohms) to ground.
Figures 3-l and 3-2 illustrate single and multiple installations with cur-
rent loop outputs.

5. Zero and Span Adjustments

The zero and span potentiometers are accessed through marked

+2%

ports

on the right side. If your zero output is more than

scale,

you

may adjust the zero potentiometer when you are absolute-

of full

ly certain that you have zero flow.
Since the output does not indicate negative numbers, it is necessary

tD

adjust down from a slightly positive reading. Slowly rotate the zero

clockwise ’uhtil

pot

a positive reading is indicated. Then turn the pot

counterclockwise slowly just until zero is reached. This completes

the zero adjustment.

Normally,

sp’an

adjustments are not made unless you are calibrating
the flowmeter, as described in Section 5. The span adjustment
should not be used unless you have a known precise non-zero flow

rate that you wish to match.

6. Attitude

Unless specified otherwise, the instrument has been calibrated for

(il5’)

installation with the flow direction in the horizontal plane

with
the enclosure facing upward. If your actual installation orientation is
different, you will have to make a small zero adjustment.

PRINCIPLE OF OPERATION
Gas enters the flow body and divides into two flow paths. Most of

the flow goes through the laminar flow bypass. This creates a
pressure drop that forces a small fraction of the flow through the sen-
sor tube.

The straight sensor tube is mounted on the top of the bypass flow
path. Since both paths are perfectly laminar, the ratio of the total flow
(m)

to the sensed flow (ml) is exactly constant. This contributes to

the flowmeter ’s exceptional accuracy. Two resistance detector

(RTD)

coils around the sensor tube direct a constant amount of heat into

the gas stream.

In actual operation, the gas mass flow carries heat from the upstream
coil to the downstream coil. The resulting temperature difference

T2-Tl

is detected by the RTD coils and gives the output signal. Since

the molecules of gas carry away the heat, the output signal is directly

and linearly proportional to gas mass flow.

The laminar flow bypass makes changing of flow ranges easy with
the proper calibration facilities. Each of the two bypasses in the op-
tional Laminar Flow Bypass Set has a combination of rectangular

slots along its circumference as shown in Figure 3-5 below.
To change the flow rate of the flowmeter, follow the instructions pro-

vided with the Laminar Flow Bypass Set and cut away the gates
leading to the right combination of laminar flow paths in one of the
two bypasses. This procedure requires calibration facilities and

minimal skills in electronics.

9

4-20mA

SIGNAL

4-20mA

POWER
SUPPLY

+15v

COM

Ffgure

Figure 3-1.

3-2.

Single Unit 4-20 Hookup

.--

Multiple Installation 4-20 Hookup

10

STAAIGHTym

SEN53R

#

LAMINAR FLOW BYPASS

i_L ’

TUBE

Figure 3-3.

SENSOR TUBE

3-4.

Figure

F;;--“GATES”

SECT. A-A

Two Flow paths

‘-ANT HEAT, H

rineasc,

-

RTD COILS

r.#

A

--

A

Figure 3-5.

Laminar

Flow Bypass Set

SECTION 4 MAINTENANCE

The FMA-5000 Series essentially requires no maintenance and has
no regular maintenance schedule, other than periodic flow path
cleaning if the gas is dirty. Calibrations may be scheduled once or
twice yearly, depending on the accuracy to be maintained, or as
needed.

4.1

4.1.1

4.1.2

Flow Path Cleaning
The flow path (wetted parts)

(sensor tube1 and Viton O-rings (standard).

If you wish to clean the flowmeter, purge it thoroughly
before disconnecting from the gas line when toxic or cor-
rosive gases are used. Never return the instrument to
OMEGA for repair or calibration without fully neutralizing
any toxic gases trapped inside.

Refer to the exploded drawing of the transducer in Appendix 1 when
performing the following procedures. All cleaning of the flow path

can be accomplished with Freon, alcohol or any cleaner safe for the

listed materials.

Inlet and Outlet Screen
Remove inlet and outlet fittings

12)

and either replace or clean the inlet and outlet screens (No.

(No.

14).

Flow

Laminar
Remove the inlet and outlet fitting as in Section 4.1.1. The LFE has a

slightly tapered shape with the larger diameter upstream (on the in-
let side). To remove the LFE for cleaning, push it out the inlet side from
the outlet side using a blunt object which does not mar the flow chan-
nels. A
to carefully clean all active flow channels in the LFE. When reinstalling
the LFE, it is of utmost importance to press it in the correct distance.
Refer to Figure 4-1.

Element

3/s”

nut driver is perfect for this job. When cleaning, be sure

(LFE)

5% glass-filled Nylon

ale

(Na 13). pull out the LFE hold-downs

6/6;

316 SS

12

Figure 4-l.

4.1.3 Sensor Tube

LFE Location Within the Flow Body

Opening

Do not remove the PCB bracket (No.

the

sensor cavity

will shift calibration.

7)

unless it is absolutely
necessary to gain access to the sensor cavity. Doing so will shift the
calibration more than 2%. The remaining parts of the flow path are
disassembled as shown in the exploded view in Appendix 1. Note the
position of the insulation blanket before removal and reinstall in the
same manner. After removal, the sensor tube (No.
ed by purging, washing with a solvent, or by

51

rodding

can be clean-

out the 0.031
inch I.D. tube with a 0.029-0.030 inch O.D. rod or wire. To maximize
the time response, the sensor tube has thin walls. Therefore, when
cleaning, be extremely careful not to bend the sensor tube or to mar
its inlet or outlet edges. It is important when reinstalling the sensor
to make sure that no torque is imparted on the sensor tube. Torque
can be eliminated by using a good quality oxygen compatible grease
on the sensor sealing O-rings. The sensor assembly should slide free-

totwist

ly into the cavity flanges without having

it. Twisting will im-

part undesirable torque on the sensor and could lead to long term shif-
ting of the zero value Also, take care to not disturb or unravel the sen-
sor windings.

13

SECTION 5 CALIBRATION

5.1

5.2

GENERAL FLOW CALIBRATION PROCEDURE
Flow calibration requires a calibration standard of at least double ac-

curacy and preferably an order of magnitude better. Most calibrations
can be done using dry nitrogen and the

“K” factors and gas tables

given in Appendix 4.

RECALIBRATION OVER THE SAME FLOW RANGE
Flow recalibration is performed by using the following procedure.

Refer to the electrical schematics in Appendix 2. Calibration checks
and minor adjustments to the zero and full scale may be made via the
access ports in the side of the enclosure. If the linearity needs adjust-
ment (as may be required when installing a different laminar flow ele-
ment bypass to.change the range), go to Step 4.

Step 1

Warm-Up: Plug in the flowmeter to be calibrated and allow

at least 15 minutes warm-up time before attempting any
adjustments.

Step 2

Zero Adjust: Slide open the zero and span access ports on

the side. Using a voltmeter connected to the meter output

Step 3

pins, adjust the zero potentiometer

for 4-20

outputs).

mA

(R5)

for zero flow

Check Full Scale: Generate the full scale flow using a meter-

mA

(4

ing valve in line with the instrument under test. Compare the
indicated flow rate with the flow standard reading. If they
agree to within

ilO%,

adjust the span potentiometer

(R21)

for exact agreement. If the readings do not agree within

*lo%,

attempt to determine the cause of disagreement.

Possibilities are:

Partially clogged or dirty sensor tube

al

Wrong or improper use of K factor

b)

Wrong or improper correction for temperature and

Cl

pressure

Leaks in the system or in the flowmeter

d)

Replacement of parts in the flow path do not exactly

e)

match the original parts.

gD

to

This completes the calibration procedure To adjust linearity,

Step

4.
Step 4

Adjusting Linearity: First gain access to the printed circuit
board inside the enclosure by using the procedure describ-
ed in Section 2.4.3. Orient the meter so that the component

plug

side of the circuit board is facing you.

allow it to

warm up for at least 15 minutes.

in the meter and

14