Alnor RVA+ User manual

Model RVA+
Rotating Vane
Anemometer
OWNER’S MANUAL

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LIMITATION OF WARRANTY AND LIABILITY
Seller warrants that this product, under normal use and service as described in
the operator's manual, shall be free from defects in workmanship and material
for a period of 24 months, or the length of time specified in operator's manual,
from the date of shipment to the customer. This limited warranty is subject to
the following exclusions:
a. Batteries and certain other components when indicated in specifications are
warranted for a period of 90 days from the date of shipment to the
customer.
b. With respect to any repair services rendered, Seller warrants that the parts
repaired or replaced will be free from defects in workmanship and material,
under normal use, for a period of 90 days from the date of shipment to the
customer.
c. Seller does not provide any warranty on finished goods manufactured by
others. Only the original manufacturer's warranty applies.
d. Unless specifically authorized in a separate writing by Seller, Seller makes
no warranty with respect to, and shall have no liability in connection with,
any goods which are incorporated into other products or equipment by the
Buyer. All goods returned under warranty shall be at the Buyer’s risk of
loss, Seller’s factory prepaid, and will be returned at Seller’s risk of loss,
Buyer’s factory prepaid.
The foregoing is IN LIEU OF all other warranties and is subject to the
conditions and LIMITATIONS stated herein. NO OTHER EXPRESS OR
IMPLIED WARRANTY OF FITNESS FOR PARTICULAR PURPOSE OR
MERCHANTABILITY IS MADE.
THE EXCLUSIVE REMEDY OF THE USER OR PURCHASER, AND THE
LIMIT OF THE LIABILITY OF SELLER FOR ANY AND ALL LOSSES,
INJURIES, OR DAMAGES IN CONNECTION WITH THIS PRODUCT
(INCLUDING CLAIMS BASED ON CONTRACT, NEGLIGENCE, STRICT
LIABILITY, OTHER TORT, OR OTHERWISE) SHALL BE THE RETURN OF
THE PRODUCT TO THE FACTORY OR DESIGNATED LOCATION AND THE
REFUND OF THE PURCHASE PRICE, OR, AT THE OPTION OF SELLER,
THE REPAIR OR REPLACEMENT OF THE PRODUCT. IN NO EVENT SHALL
SELLER BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES. SELLER SHALL NOT BE RESPONSIBLE
FOR INSTALLATION, DISMANTLING, REASSEMBLY OR REINSTALLATION
COSTS OR CHARGES. NO ACTION, REGARDLESS OF FORM, MAY BE
BROUGHT AGAINST THE SELLER MORE THAN ONE YEAR AFTER THE
CAUSE OF ACTION HAS ACCRUED.
The purchaser and all users are deemed to have accepted the terms of this
LIMITATION OF WARRANTY AND LIABILITY, which contains the complete
and exclusive limited warranty of Seller. This LIMITATION OF WARRANTY
AND LIABILITY may not be amended or modified nor may any of its terms be
waived except by a writing signed by an authorized representative of Seller
Service Policy
Knowing that inoperative or defective instruments are as detrimental to TSI as
they are to our customers, our service policy is designed to give prompt
attention to any problems. If any malfunction is discovered, please contact your
nearest sales office or representative, or call Customer Service department at
[phone] (USA) and (1) 651-490-2811 (International).

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TABLE OF CONTENTS
SECTION 1 General Description.................. 2
SECTION 2 Safety ......................................... 3
SECTION 3 About the RVA+......................... 3
Installing the Batteries ............................. 3
LCD display ............................................. 4
Auto Shut Off ........................................... 4
SECTION 4 Detailed Operation .................... 4
English/Metric Unit Selection ................... 5
Measuring Air Velocity ............................. 5
Measuring Air Volume ............................. 6
Low Battery Indication.............................. 7
SECTION 5 Helpful Information in Using
Rotating Vane Anemometers................ 8
Flow Rate in Larger Areas ....................... 8
Use on Grilles .......................................... 9
“Sweep” Technique.................................. 9
Calculating Volume Flow Rate............... 10
SECTION 6 Care and Maintenance............ 11
SECTION 7 Service and Calibration
Information........................................... 12
Damaged in Transit ............................... 13

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SECTION 1
General Description
The RVA+ is intended for measurement of air
velocity and volume flow at return grilles, fume
hoods, kitchen exhausts etc. It uses rotating
vane anemometer technology. Air movement
causes rotation of a multi-blade fan mounted in
low-friction bearings. An infrared sensor
translates fan blade movement into measured air
velocity.
The RVA+ features a 270-degree rotating head
with detents at every 90° and will function
satisfactorily in any angular position. This
allows the LCD display to be viewed from the
front of the instrument while the head is
oriented with the flow direction.
In addition, the temperature of the air flow is
measured and displayed simultaneously with
the flow reading.

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SECTION 2
Safety
Observe common sense safety precautions
when using the RVA+. Exercise care to ensure
that the instrument does not interfere with any
moving equipment or electrical wiring
This instrument is not designed for gas mixtures
other than air. Use with explosive and/or other
dangerous gas mixtures is not recommended
and is at the user’s own risk.
SECTION 3
About the RVA+
Installing the Batteries
The RVA+ requires 4 AA batteries. The
batteries are not installed when the instrument is
shipped. Remove the battery cover by pressing
on the latch. Install the batteries noting the
correct polarity orientation.
For replacing the batteries, remove the top
batteries first.

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LCD display
The large four digits will display the velocity or
volume reading. The smaller digits near the
upper left corner will always display
temperature.
There are a total of 13 arrow indicators, seven
along the top of the display and six along the
bottom of the display. These indicators show:
units of measure, statistics (min, max, avg.),
the X1000 multiplier, and area.
Auto Shut Off
The RVA+ has an auto shut off feature to help
preserve battery life. If no keys are pressed for
10 minutes, the instrument will automatically
turn itself off. This function cannot be disabled
by the user.
SECTION 4
Detailed Operation
Press the ON\OFF key to turn the RVA+ on and
off. When the instrument is first turned on, it
briefly illuminates all the LCD display
segments. Next, the instrument will display

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"rdY" indicating it is ready to take a
measurement.
The RVA+ powers up to the unit of measure
used last.
English/Metric Unit Selection
To select between English and metric units, be
sure that the display indicates "rdY". Press and
hold the ▼key for approximately five seconds.
The display will show "EnG"or "NNEt".
Release the ▼key. Use either the ▲or ▼key
to make your selection. Press MODE/CLEAR
key to accept the selection and return to "rdY".
Measuring Air Velocity
With the RVA+ displaying "rdY", select
velocity units using the ▲or ▼arrow keys. In
order to take a velocity reading, hold the
rotating vane in the airstream noting the flow
direction arrow on the instrument head. Keep
the vane in the airstream about five seconds
before pressing READ key to take a reading.
This enables the vane anemometer to reach
steady speed and the average reading will be
more accurate.

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To take a single reading, press READ key
momentarily. The instrument will beep and the
measured value will be displayed.
To take a time averaged reading, press and hold
READ key for the desired time period. The
instrument will beep approximately every
second. Release the READ key to stop the
measurement and display the average value.
After a time averaged reading is made, the user
can view the average, maximum and minimum
values of the measuring sequence. Press the ▲
or ▼key to display a particular value. Press
MODE/CLEAR key to return to "rdY".
Measuring Air Volume
The operation for air volume measuring is the
same as air velocity. Once a volumetric unit of
measure is chosen, the RVA+ is in volume
mode. Use the arrow keys to choose your units
of volume measurement. When the display
shows "rdY", press MODE/CLEAR key. The
display will change to "ArEA" (if "ArEA" does
not show on the display, RVA+ is not in
volume mode).
Press READ key. The display will show the
previously entered area value. Use the ▲or ▼

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key to enter a new value. Press MODE/CLEAR
key to accept the value and return to "rdY". To
take a volume measurement, use the READ key
as you would when taking a velocity
measurement.
The area value must be in either ft2 for English
units or m2for metric units. To calculate the
square area of your measurement area, use the
formulas:
square or rectangle:
length x width = square area
round:
πx r2= square area
where π≈3.14 and r = radius
Note:If dimensions are in inches, divide the
result by 144 to obtain ft2, if in
centimeters, divide the result by 10000 to
obtain m2. Refer to Section 5 for more
details.
Low Battery Indication
When the "LO BATT" icon appears, the RVA+
has about 10 minutes of battery life remaining
after which the instrument will display "Batt"
and shut off.

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SECTION 5
Helpful Information in Using
Rotating Vane Anemometers
When used in airstreams of similar size to or
smaller than the RVA+ head, blockage effects
may occur. Velocity readings should be
considered a relative measurement in this case.
This effect is somewhat variable depending on
the size of the airway and the distance from the
duct walls. If the area is larger than 2.15 ft2
(0.2 m2) the effect should be minimal.
Note: The RVA+ can display an averaged
result of multiple readings in both
velocity and volumetric modes.
Flow Rate in Larger Areas
When checking air velocity or volume flow rate
over large areas, multiple spot readings should
be taken. When taking multiple readings, it
should be noted that large variations may be
observed between individual readings. In
general, the more readings taken, the more
accurate the averaged result will be.

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Use on Grilles
Better measuring conditions can be obtained on
grilles with adjustable direction vanes if the
vanes on the grilles are temporarily straightened
before making measurements. This should not
significantly affect the flow rate as long as any
built in dampers are not accidentally disturbed.
It is advisable to use the aperture (the actual
effective area of air flow), not the surface area
of the grill, in any flow rate calculation. The
RVA+ is suitable for both supply and exhaust
grilles, and the procedure for both is the same
except that the direction arrow on the
instrument head must be aligned correctly with
the direction of the air flow. The head should be
held close to the grille on exhaust, but the head
should not touch the grille.
“Sweep” Technique
In addition to traditional traverse methods some
users prefer to use a “sweep” technique. A
continuous and uniform movement of the
RVA+ over the entire measurement plane while
READ key is depressed will produce a time
averaged reading.
Users attempting to rely solely on this method
should verify their “sweep” technique against
conventional traverse methods.

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Calculating Volume Flow Rate
Volume flow rates through airways or apertures
may be calculated if the cross-sectional area of
the airstream and its average velocity are
known. To arrive at volume flow rate, the cross-
sectional area of the airstream is multiplied by
the average airstream velocity, using the same
units of linear measurement throughout the
calculation.
EXAMPLE:
The dimensions of a rectangular opening to a
kitchen exhaust hood is 36 x 72 in. The average
air velocity is 138 ft/min (fpm). Using the
formula for determining the area of a rectangle,
you would obtain an area of 18 square feet.
36 x 72 in. = 2592 in.22592 / 144 = 18 ft2
Inputting the area and the average velocity into
the volume flow formula, you will obtain 2484
ft3/min (cfm).
Q = AV (area x velocity)
Q = 18 ft2 x 138 ft/min (fpm)
Q = 2484 ft3/min (cfm)

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The procedure is the same when working in
metric units, but the velocity readings will be in
m/s. The opening area should be calculated in
m2, and the answer will be in m3/s.
EXAMPLE:
A rectangular opening measures 600 x 400 mm
(0.6 x 0.4 m) and twelve readings of velocity
have been taken. The readings are added
together and the result is divided by 12. In this
example, the average velocity is 3.025 m/s. The
opening’s cross-sectional area is: 0.6 x 0.4 m =
0.24 m2. Therefore, the volume flow rate is 0.24
m2 x 3.025 m/s = 0.726 m3/s. This figure should
be multiplied by 3600 to arrive at cubic meters
per hour, or by 1000 to give the answer in liters
per second. 0.726 x 3600 = 2613.6 m3/h or
0.726 x 1000 = 726 l/s.
SECTION 6
Care and Maintenance
• Remove batteries from instrument if not
used for an extended period of time.
• Do not bend or touch blades, accuracy will
be affected.

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• Do not immerse in liquids.
• Do not drop the instrument.
• Use carrying case for storage, transport, and
protection from dust.
• Use a clean damp cloth to wipe the
instrument case. Do not wipe the blades.
Return the RVA+ for service in case the
instrument was dropped, blades were deformed,
or liquid spilled on the instrument, the blades in
particular.
SECTION 7
Service and Calibration
Information
Please return your Product Registration Card
immediately. This allows us to send service
reminders, special offers, and important
information about your product.
Before sending your instrument for calibration
or repair, you should call Customer Service.
The service department will provide you with
the cost of service or calibration, Return

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Material Authorization (RMA) number, and
shipping instructions.
Send the instrument prepaid. Securely package
your instrument in a strong container
surrounded by at least two inches (5 cm) of
suitable shock-absorbing material. Mark the
outside of the shipping container with the RMA
number. Also include the purchase order
showing instrument model number, cost of
service and/or calibration, and the RMA
number. This will expedite processing of your
instrument when we receive it. See back cover
for factory address.
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

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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.

MODEL RVA+ SPECIFICATIONS
(subject to change without notice)
Measurement Range:
Velocity 50 - 6000 fpm (0.25 - 30 m/s)
0.57 - 68 mph (0.9 - 110 km/h)
Temperature 32 - 140 °F (0 - 60 °C )
Displayed Volumetric Flow Rate:
4 - 5400 x 1000 cfm (1.9 - 2548 x
1000 l/s;
6.8 - 9174 x 1000 m3/h)
Actual range is a function of velocity x area input.
Area Input 0.08 - 900 ft2(0.007 - 83 m2)
Display Resolution:
Velocity 1 fpm (0.001 m/s under 10.00 m/s,
0.01 m/s otherwise)
Temperature 1 °F (1 °C)
Accuracy:
Velocity ±(1% reading + 4 fpm or 0.02 m/s)
Temperature ±2 °F (1 °C)
Display:
4 digit, 0.45 in. (11 mm) high LCD with 2.5 digit, 0.15 in.
(3.8 mm) high temperature indicator
Instrument Storage Temperature:
14 - 140 °F (-10 - 60 °C)
Instrument Operating Temperature:
32 - 140 °F (0 - 60 °C)
Power Source:
4 AA-size Alkaline or NiCd batteries
Battery Life:
Approximately 24 hours continuous use
Overall Dimensions:
11.5 L x 4.0 H x 1.8 D in. (29.2 L x 10.2 H x 4.7 D cm)
Weight: (batteries included) 13.1 oz. (370 g)

____________________________________________
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TSI Incorporated
Alnor Products
500 Cardigan Road
Shoreview, MN 55126 USA
Toll Free [phone] June 2002
Telephone [phone] Printed in USA
Fax [phone] Part No. 116-159-210 Rev. 2
www.alnor.com Copyright 2002
[email protected] TSI Incorporated