TSI/Alnor 6200D User manual

ALNOR® LOFLO BALOMETER®

CAPTURE HOOD

OWNER’S MANUAL

P/N 116620001, REV 08

SEPTEMBER 2014

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TABLE OF CONTENTS

Section 1 General Description ................................................ 1

Section 2 Theory of Operation ................................................ 1

Section 3 Safety ...................................................................... 2

Section 4 Instrument Setup and Storage ................................ 2

Section 5 About the Instrument Display .................................. 4

Section 6 Getting Started ........................................................ 5

Section 7 Detailed Operation .................................................. 5

Section 8 Troubleshooting ...................................................... 8

Section 9 Maintenance ........................................................... 9

Section 10 Service Information ............................................... 10

Appendix A Correction Factors for Standard

Flow Rate to Actual Flow Rate ............................. 11

Appendix B Model 6200 LoFlo Balometer® Capture Hood Field
Setting Instruction for User Programmable

Correction Factors ................................................ 12

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SECTION 1

General Description

The Alnor® LoFlo Balometer® Capture Hood is a
compact instrument that measures very low air
flow rates in HVAC systems. It measures from 10
to 500 cfm (17 to 850 m3/h, 4.7 to 236 l/s). The
LoFlo Balometer® Capture Hood displays standard
air volume rate when placed at supply or return
diffusers, registers, or grilles located on the
ceiling, wall, or floor.

The LoFlo Balometer® Capture Hood has a vent
mechanism which reduces the restriction of air
flow caused by the instrument. This unique venting
system (patent pending) allows the instrument to
remain compact while still measuring a wide range

SECTION 2

Theory of Operation: Capture Hoods

and Thermo-anemometry Sensing

As air exits a diffuser, it is captured in the hood or
base and directed over a manifold. The manifold
averages the velocity pressure and directs air over
the sensors. The velocity and temperature of the
air passing through the manifold are sensed, using
a constant temperature thermo-anemometer
principle. The voltage output from the sensor is
then calibrated for the entire volume rate passing
through the LoFlo Balometer® Capture Hood.

All capture hoods are susceptible to “odd” air flow
patterns. “Odd” could refer to any air flow pattern
different from the pattern where it was calibrated.
Substantial negative effects can be observed
when using a large hood on a small diffuser. For

of volume rates. The LoFlo Balometer® Capture
Hood should be used with the vents closed at
lower volume rates, but higher volume rates
should be measured with the vents open to
minimize any resistance effects. A 2-point
measurement may be taken to compensate for the
resistance effect of the instrument at higher
volume rates.

The LoFlo Balometer® Capture Hood is battery
powered and may be used with or without optional
hoods. It weighs just over 6 pounds with the 2' x 2'
hood, helping to reduce worker fatigue.

example, using a 2' x 2' hood on a 10" x 10"
diffuser. This creates large recirculation regions on
the sides of the fabric hood and causes an “odd”
air flow pattern as it passes over the manifold. It is
recommended to match the hood closely to the
size of the diffuser.

 NOTE: Throughout this manual, the units cfm,

m3/h and l/s are used for simplicity. Note,
however, that the LoFlo Balometer® Capture
Hood actually reads in standard cubic feet per
minute (scfm), standard cubic meters per hour
(std. m3/h), or standard liters per second
(std. l/s).

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2

C A U T I O N

WHILE USING THE LOFLO BALOMETER

®

INSTRUMENT TO TEST AIR FLOW IN DUCTS, YOU
MAY COME INTO CONTACT WITH OR BE EXPOSED TO DUST, POLLEN, MOLD, FUNGUS, OR
OTHER AIRBORNE CONTAMINANTS. IF YOU ARE OR MAY BE SENSITIVE TO DUST, POLLEN,
MOLD, FUNGUS, OR OTHER AIRBORNE CONTAMINANTS, ALWAYS USE AN APPROPRIATE
MASK OR RESPIRATOR WHILE EMPLOYING THE LOFLO BALOMETER® INSTRUMENT.

SECTION 3

Safety

When using the LoFlo Balometer® Capture Hood
to check air flow at ceiling diffusers, make certain
that you can safely raise and hold the unit while
making measurements. Be especially careful
when working on a ladder.

Observe all necessary precautions so that the unit
does not become caught in moving machinery or
touch any exposed electrical wiring.

SECTION 4

Instrument Setup and Storage

Hood Setup

1. Locate the four (4) aluminum channels for the
hood and position them into a square with the
foam facing up. Slide the “U” opening on the
channel end (Fig. 1) and corner bracket
toward the brass eyelets until you feel it latch.

2. Continue with the other two channels until you
have a square frame that is locked tightly in all
four corners.

3. Locate the hood for the frame size you have
assembled.

The LoFlo Balometer® Capture Hood is not
designed for gas mixtures other than air. Use with
corrosive or other dangerous or explosive gas
mixtures is not recommended and is at the user’s
risk.

the base. Rotate the hood assembly until the
metal cups are above the spring-loaded pins.

8. Locate the hood support rods. Extend the
hood so it is taut and insert one support rod
onto the spring-loaded pin closest to you.

9. Push the support rod down and insert the top
end of the rod into the metal cup on the hood
frame. Fig 1.

10. Install the rod on the opposite side then install
the last two rods.

4. Position a corner seam of the hood onto the
corner of the frame. Stretch the nylon hood to
an adjacent corner until the hood corner
meets the frame corner.

5. Push the elastic cord into the channel along
the side of the frame.

6. Repeat steps 4 and 5 until the hood assembly
is complete and ready to mount onto the base.

7. Place hood on a table or clean floor with the
base inside the opening. Pull the hood over

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Hood Frame Channel

Figure 1

3

Instrument Storage

The hood and frame assemblies can be detached
from the instrument base and placed inside their
own carrying case without disassembly.

The LoFlo Balometer® Capture Hood should
always be turned off before re-packing the
instrument. If storing the LoFlo Balometer®
Capture Hood for an extended period of time,
remove the batteries to prevent damage due to
leakage.

Battery Installation

To install the 4 C-size batteries that ship with the
LoFlo Balometer® Capture Hood:

1. Make sure the LoFlo Balometer® Capture
Hood switch is off.

2. Remove the battery cover located on top of
the meter.

3. Slide the battery holder up until the snap
connector is exposed.

4. Disconnect the battery holder from the LoFlo
Balometer® Capture Hood.

5. Install the 4 C size batteries in the holder.

6. Reconnect the snap connector and slide the
battery holder into the battery compartment.

7. Replace battery cover.

3

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SECTION 5

Index No.

Name

1

LCD

2

On/Off Switch

3

Supply/Return Button

4

Manual Range Button

5

Handle Button

6

Battery Holder

7

Vents

8

Vent Open/Close Slide

Index No.

Name

1

Digital Readout

2

Simulated Analog Display

3

Manual Range Indicator

4

Supply/Return Indicator

5

2-Point Mode Indicator

6

Vent Indicator

7

Units Indicator

8

Low Battery Indicator

About the Instrument Display

This display is an analog display, simulated with
26 LCD segments to give the user the response of
a mechanical Balometer® Capture Hood. It also
displays an exact digital number, using 3½ digit
numeric section. The LCD has indicators for
supply, return, manual range, vent modes, and low
battery.

Figure 3 shows the front of the LoFlo Balometer®
Capture Hood.

Figure 4 shows the LCD.

Figure 3

Front View of LoFlo Balometer® Capture Hood

Figure 4

LoFlo Balometer® Capture Hood LCD

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Supply/Return Button

The LoFlo Balometer® Capture Hood is in supply
mode when turned on. This is indicated on the
display with the supply indicator . To take return

air measurements, press the supply/return button
on the front of the meter. Return air mode will be
indicated on the display with the return indicator

.

Significant errors may result if:

 Instrument is not in proper mode.

 Fabric hood is not used with vent open

mode.

Vent Closed/Vent Open Modes

When the instrument is turned on, it is in the vent
closed mode . When the vent closed indicator
is on, the vents must be closed to take the
measurement. Close the vents by loosening the
thumbscrew and sliding the vent baffle to the fully
closed position and locking the vent in place
again.

The vent open mode is indicated with the vent
open indicator on the LCD . Open the vents by
loosening the thumb screw and sliding the vent
baffle to the fully open position and locking it into
place again. Then press and hold the handle
switch for more than 3 seconds to switch the
LoFlo Balometer® Capture Hood to the open vent
mode.

The vent open mode was developed for higher
volume rates on larger diffusers; the 2' x 2' or 650
mm x 650 mm hood should always be used with
vent open mode.

1-Point Measurement Mode

Use Vent Closed Mode for measurements
between:

10 to 150 cfm (17 to 255 m3/h, 4.7 to 71 l/s).

 NOTE: In Vent Closed Mode, volume rates

below 8 cfm (13 m3/h, 3.6 l/s) are displayed as
0; volume rates above 517 cfm (879 m3/hr, 244
l/s) are displayed as Or.

Use Vent Open Mode for measurements between:

150 to 500 cfm (255 to 850 m3/h, 71 to 236 l/s)

 NOTE: In Vent Open Mode, volume rates

below 150 cfm (255 m3/h, 71 l/s) are displayed
as Ur; volume rates above 517 cfm (879 m3/h,
244 l/s) are displayed as Or.

2-Point Measurement Mode—Supply Only

To activate the 2-point measurement mode, turn
the instrument off. While pressing the handle
button, turn the instrument back on. The 2-point
mode indicator will show.

The 2-point measurement mode takes both vent
open and vent closed measurements to calculate
a resistance-compensated volume flow rate.

The process starts with the vents closed and the
display showing the vent closed indicator.

1. Place the LoFlo Balometer® Capture Hood

over the diffuser to be measured and press
the handle switch once to take the vent closed
measurement.

2. The instrument stores that reading.

3. The display will now show the open vent

indicator and you should open the vents.

 NOTE: Make certain you are using a fabric

hood when in 2-point mode.

4. Again place the LoFlo Balometer® Capture

Hood over the diffuser to be measured and
press the handle switch to take the vent open
measurement.

The default mode of the LoFlo Balometer®
Capture Hood is the 1-point measurement mode.
If you are in 2-point measurement mode, simply
turn the instrument off and turn back on.

The 1-point measurement mode is described in
the Getting Started section earlier in this manual.
This is the faster, simpler way to take
measurements.

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5. The instrument calculates and displays the

compensated reading.

6. The numeric display will flash; press the

handle switch again and the instrument will
display the vent closed indicator. Close the
vents.

7. Return to Step 1 to take another resistance

compensated reading.

 NOTE: Return to 1- point measurement mode

at any time by turning the power off and on.

7

Condition

Reason

The vent closed or vent open measurement is less
than 150 cfm (70 l/s, 255 m3/h).

 Calculations are not made at the low end since

the effect is small and can generally be
neglected. Use 1-point mode.

The vent closed or vent open measurement is
greater than 500 cfm (235 l/s, 850 m3/h).

 Calculations are not made beyond the calibrated

range.

The vent open measurement minus the vent closed
measurement is too small (< 0).

 A mistake has occurred in the process. Repeat

the two-point measurement.

 The resistance effect is small and was

overwhelmed by natural fluctuations. Use single­point mode.

The vent open measurement minus the vent closed
measurement is too large.

 A mistake has occurred in the process. The vent

may not have been open for the open vent
measurement. Repeat the two-point
measurement.

 The effect is beyond the range of the

compensation equation. Perform a traverse of the
system instead.

When “–––” is displayed at the last step of the 2-point mode, the calculation for the resistance effect cannot
be made. It can be caused by any of the conditions listed here.

 NOTE: The display will also show “–––” when the return mode is selected. The 2-point measurement

mode is for supply only.

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8

Symptom

Possible Cause and Corrective Action

Meter does not turn on.

 Battery holder snap connector not connected.

Connect battery holder to instrument.

 Batteries may be discharged. Charge or replace

them.

 Switch failure, wiring failure, or circuit failure. Call

TSI.

Meter reading lower than expected.

 Wrong vent mode chosen. Choose correct vent

mode, open or closed.

 Wrong air direction mode chosen. Choose

correct direction, supply or return.

 Back pressure effects could be significant. Use 2-

point measurement mode.

 Hood frame not sealing properly around diffuser

or grill. Press hood evenly against diffuser.

 Odd air flow pattern present. Perform traverse

and use proportional balancing.

 Hood torn. Replace, or repair tear with duct tape

or other non-porous material.

 Meter out of calibration. Call TSI.

 Damage to manifold. Call TSI.

Meter reading higher than expected.

 Wrong vent mode chosen. Choose correct vent

mode, open or closed.

 Wrong air direction mode chosen. Choose

correct direction, supply or return.

 Odd air flow pattern present. Perform traverse

and use proportional balancing.

 Meter out of calibration. Call TSI.

Meter not at zero at zero flow.

 Instrument not at room temperature. Allow

instrument to acclimate before turning on the
power.

 The LoFlo Balometer

®

Capture Hood is reading
real room air currents. Place on floor with a piece
of cardboard over the top to determine if it is
measuring real air currents.

 Meter out of calibration. Call TSI.

Meter displays Er.

 Self test failed. Call TSI.

Handle button not working.

 Call TSI.

SECTION 8

Troubleshooting

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SECTION 9

Maintenance

Hoods

Hoods may be cleaned in cool water with a mild
detergent.

Sensing Manifold

The manifold should be checked visually before
using to be certain that the sensing holes have not
become clogged with dirt or dust particles. Do not
immerse the manifold in water. It is recommended
that cleaning be done with extreme care with the
manifold in place. Do not use highly compressed
air to clean the manifold tubes.

Calibration

It is recommended that your LoFlo Balometer®
Capture Hood be returned to the factory once a
year for a calibration check. When shipping the
LoFlo Balometer® Capture Hood for factory
calibration, pack it carefully, and follow the
Instructions for Return in this manual.

Vent Operation

If the vent becomes difficult to operate, remove
both thumbscrews from the vent mechanism and
spray the contacting surfaces with silicone spray
lubricant. Wipe off excess and reassemble vent
mechanism.

Performance Check

If the calibration is to be checked, the best way is
to use a reference flow standard more accurate
than the LoFlo Balometer® Capture Hood. Flow
standards that may be used for this purpose
include orifice plates, venturis, nozzles, and
laminar flow elements. These devices require
accurate differential pressure, barometric
pressure, and temperature reading instruments to
measure either actual or standard volume rate.

If the LoFlo Balometer® Capture Hood is checked
against a velocity instrument such as a pitot
probe/manometer or thermo-anemometer, there
may be errors. If a velocity standard is used, the
average velocity must be obtained by taking a
traverse.* The accuracy of the traverse is
dependent on the flow uniformity, the number of
readings taken, the accuracy of the velocity
instrument, and operator expertise. This average
velocity reading must then be multiplied by the
area over which the traverse was taken.

Finally, air flow instrumentation is dependent on
environmental conditions such as temperature,
atmospheric pressure, humidity, and even
turbulence. These conditions can have very
different effects on various instrument types.
Caution must be exercised when making
comparisons.

*A traverse is a set of velocity readings taken in a
prescribed pattern which will provide an overall velocity
value when averaged together. Any of the Alnor velocity
measuring instruments can be used for this purpose.

9

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SECTION 10

Service Information

Service and Repair

Please return your Product Registration Card
immediately. This allows us to send you service
reminders, special offers, and important
information about your product.

Before sending your instrument for calibration or
repair, you should call TSI Customer Service. The
Service Department will provide you with the cost
of service or calibration, Return Material
Authorization (RMA) number, and shipping
instructions.

Please have the following information available
when you call:

 Owner’s name, address, and phone

number

 Billing address, if different and applicable
 Instrument name or model
 Serial number
 Date of purchase
 Where purchased

TSI recommends that you keep a “calibration log”
and keep all records of service on your instrument.

Instructions for Return

Send the instrument prepaid. Securely package
your instrument in a strong container surrounded
by at least two inches (5 cm) of suitable shock­absorbing material. Include the Purchase Order
showing instrument model number, cost of service
and/or calibration, and the RMA number. Mark the
outside of the shipping container with the RMA
number. This will expedite processing of your
instrument when we receive it.

Damaged in Transit

All orders are carefully packed for shipment. On
receipt, if the shipping container appears to have
been damaged during shipment, the instrument
should be thoroughly inspected. The delivering
carrier’s papers should be signed noting the
apparent damage. DO NOT DISCARD THE BOX.

If the instrument itself has been damaged, a claim
should be promptly filed against the carrier by the
customer. The selling agent will assist the
customer by supplying all pertinent shipping
information; however, the claim must be filed by
the insured. If the instrument is damaged beyond
use, a new order should be placed with TSI while
awaiting reimbursement from the carrier for the
damaged instrument.

Call TSI directly for assistance if necessary.

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APPENDIX A

Correction Factors for Standard Flow Rate to Actual Flow Rate

The LoFlo Balometer® Capture Hood measures
standard volumetric flow rate. Standard flow is
defined as the flow rate at standard conditions,
70°F (21.1°C) and 14.7 psia (29.92 inHg, 760
mmHg). Actual flow rate is the true volumetric rate
of air at the local temperature and barometric
pressure. If you desire standard flow rate, use the
displayed reading. However, if the actual flow rate
is desired, use the information below.

To correct the standard flow rate to actual flow
rate use the equation below.

V

= V

act

V

= Actual flow rate

act

V

= Standard flow rate (this is displayed

std

T

= Actual Temperature

act



= Actual barometric pressure

act



= Standard density 0.075 lb/ft3

std

a = Actual density in lb/ft3

x CF

std

by the instrument)

(at 70°F and 14.7 psia)

CF = 

Using the equations or chart below, you can
bypass the full density calculation.

Calculations in imperial units

CF = (14.7/ 

Where 

Calculations in imperial units

CF = (29.92/ 

Where 

Calculations in metric units

CF = (760/ 

Where 

For your convenience, we have made a chart for
determining the correction factor given
temperature and pressure.

 NOTE: The atmospheric pressure as reported

by the National Weather Service is corrected to
sea level and cannot be used if measurements
are not at sea level.

(Correction Factor)

std/a

)*(460+ T

act

is in psia and T

act

)*(460+ T

act

is in inHg and T

act

)*(273.15+ T

act

is in mmHg and T

act

act

is in °F

act

act

act

act

act

)/530

)/530

is in °F

)/294.25

is in °C

11

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APPENDIX B

Model 6200 LoFlo Balometer® Capture Hood Field Setting Instructions for

User Programmable Correction Factors

HISTORY:

It is well known that capture hoods are susceptible
to diffuser styles that are different from that upon
which they were calibrated. Understanding that
these productivity tools may require adjustment in
the field, the LoFlo Balometer® Capture Hood is
equipped with two separate sets of field

programmable correction factors, “FLD A” and
“FLD B”, that allow for a field calibration of the

instrument to different diffusers.

DETERMINING FIELD PROGRAMMABLE
CORRECTION FACTORS:

Correction factors are simply the relation between
the actual volume flow rate and that which is
displayed on the LoFlo Balometer® Capture Hood.
The actual volume flow rate is most accurately
established through performing a duct traverse.
The correction factor is then determined as the
ratio of the actual volume flow rate divided by the
volume flow displayed on the LoFlo Balometer®
Capture Hood set in the factory calibration setting
(default from factory). The number obtained is
used as the multiplier for that particular diffuser.

Example:

Duct Traverse yields 120 CFM
LoFlo Balometer® Capture Hood in Supply Mode

with Vents Closed yields 107 CFM

Correction Factor = 120/107 = 1.121

Because there are no decimal points available for
the correction factor values, this number will be
programmed into the LoFlo Balometer® unit as

1121.

If all available operating modes of the LoFlo
instrument are to be used, a separate multiplier
must be determined for each mode. The four
available modes are:

• Supply, Vent Closed (10-150 CFM)

• Supply, Vent Open (150-500 CFM)

• Return, Vent Closed (10-150 CFM)

• Return, Vent Open (150-500 CFM)

PROGRAMMING THE CORRECTION FACTORS
TO THE INSTRUMENT:

Once the multipliers have been determined, the
correction factors are programmed to the LoFlo
instrument using the following steps:

1. Turn the instrument off.

2. Press and hold the range selector button
while simultaneously switching the instrument

on. The display will show “FAC” with the seven

segment characters, indicating the unit is in its
default factory setting.

3. Use the supply/return button to cycle

through the available storage fields, “FLD A”,
“FLD B” or “FAC”. Use the handle hold switch
to select the desired field. If “FLD A” or “FLD
B” are selected, the field letter chosen will be

displayed at the upper right of the LCD
throughout the programming cycle. Note that

the factory calibration setting, “FAC”,

cannot be altered.

4. Once the desired storage field has been
selected, the unit will display the symbols for
the Supply, Vent Closed mode, along with the
current correction factor programmed for that
mode. The factory default coefficient for each
mode within both of the programmable storage
fields is 1000 (recall that decimal points are not
available, and thus the stored value of 1000 is
actually 1.000). Use the supply/return button to
increase the coefficients value, or the range
selector button to decrease the value as
desired. When the correct multiplier is
displayed, press the handle hold switch to store
the value. The display will then cycle to the
Supply, Vent Open mode (indicated by the
appropriate symbols), again allowing for
increasing/decreasing of the multiplier to the
desired set-point as described above. This
process will repeat for the remaining two
operating modes (Return, Vent Closed; and
Return, Vent Open).

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5. Once a correction factor has been selected and
stored for each of the four operating modes,
the unit will proceed into operation using the
programmed coefficients of the storage field

that was selected. Once again, use of “FLD A”
or “FLD B” will be indicated by the field letter

chosen being displayed at the upper right of the
LCD throughout the operating cycle. The
selected storage field will remain as the start­up default setting unless changed by the user.

6. To return to the factory calibration setting,

“FAC”, press and hold the range selector

button while simultaneously switching the

instrument on. Select the “FAC” setting by

depressing the handle hold switch. The factory
calibration has just been restored as the default

operating setting. Stored coefficients in “FLD
A” and “FLD B” will remain for future use.

NOTES:

• Always use the factory calibration setting,

“FAC”, in determining the correction factors.

• Correction factors must be in the range of

0.250 to 1.999 (0250 to 1999 without the
decimal point).

• Use of correction factors greater than 1.000

may cause the display to indicate a flow value
at zero flow (typically 12-13 CFM at zero flow).
This is normal and will limit the use of
correction factors at the extreme low-end of the
operating range.

• Do not use measurements which are less than

10 CFM * correction factor. For example, if you
program a correction factor of 1.5, do not use
measurements less than 15 CFM (10 * 1.5 =

15).

13

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Alnor Products, TSI Incorporated

Visit our website www.alnor.com for more information.

P/N 116-620-001 Rev. 08 ©1998–2014 TSI Incorporated Printed in U.S.A.

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