TSI Instruments Alnor Velometer 6000 Series User manual

®
A TSI Company
®
Velometer®
Series 6000
OWNER’S MANUAL

1
TABLE OF CONTENTS
Using the Velometer Safely 2
General Description 3
Meter 3
Range Selector 4
Pitot Probe 5
Lo-Flow Probe 5
Diffuser Probe 6
Static Pressure Probe 6
Preparation for Use 7
Diffuser Probe 7
Static Pressure Probe 8
Pitot Probe 9
Lo-Flow Probe 9
Operation 10
Procedure for Measuring Velocity with Lo-Flow Probe 10
Velocities at Suction Openings—Except Diffusers
or Grilles 10
At Grinding or Buffing Wheels 10
At Spray Booths 10
Velocities at Plating Tanks 10
Procedure for Measuring Diffuser, Register and Grille
Velocities with Diffuser Probe 11
Typical Diffuser Air Flow Measuring Procedure 11
Procedure for Measuring Static Pressure 13
Procedure for Air Flow Measurement in Ducts 13
Determining Cross-Section Areas 14
Measuring Duct Velocity 14
Troubleshooting and Maintenance 16
Troubleshooting Guide 16
Maintenance 17
General 17
Cleaning of the Velometer 17
Replacement Parts and Accessories 17
Replacement of the Range Selector Filter 17
Replacement of O-Rings in Probes 18
Replacement of O-Rings on the Meter 18
Calibration 18
Service Information 19
Instructions for Return 20
Ownership/Calibration Log 21

2
WARNING
!
USING THE VELOMETER SAFELY
All necessary precautions must be observed when operating the Velometer
in the vicinity of moving equipment such as motors and blowers. The user
must exercise care to ensure that the probe or the instrument does not in-
terfere with any moving equipment.
The maximum temperature at which the Velometer can be used is 250°F
(120°C). The maximum pressure difference between the inside of the in-
strument housing and ambient is 4.2 psi. (8.6 gm/cm2). The Velometer is
not designed for gas mixtures other than air.
Any use beyond the operational temperature or pressure limits, or on gas-
ses which are either combustible or may deteriorate materials in the
Velometer, is not recommended and is at the user’s risk.
Opening or otherwise attempting to service your Alnor instrument will void
the warranty. Please read the warranty statement carefully.
WARNING
!CAUTION

3
GENERAL DESCRIPTION
The Alnor Velometer is a direct reading instrument for measuring air ve-
locities. It is designed to measure velocities inside heating and ventilating
ducts, or in open areas such as at fume hoods, grilles, diffusers, slots on
ventilated plating tanks, and so forth. It may also be used for measuring
duct static pressures.
The Velometer set consists of the meter, velocity and static pressure Range
Selectors, measuring probes and connecting hoses.
The Velometer is basically an air flow meter reading in feet per minute (or
meters per second).
The Velometer is built with a taut band meter movement; it is carefully
balanced so that you may hold the meter in any normal position and still
get an accurate reading. All Velometers are uniformly calibrated to fac-
tory standards: optimum accuracy is attained when velometers are used with
accessories of the same set, and with the meter in the horizontal position
(scale window facing up).
Before using the Velometer, study the operational instructions and proce-
dures to insure proper use of the instrument for accurate results.
Meter
The meter receives air through its sensing ports. A force against the vane
causes a deflection of the needle which yields an indicated reading.
On the face of the meter there is a series of range scales (A) which enables
you to read accurately the measured value. Since there are a number of
ranges, it is important that the scale read on the meter face corresponds to
the velocity or static pressure range that is set on the Range Selector.
On the back side of the meter there are two sensing ports (hose connec-
tions) (B) which are for interconnecting to one of the two Range Selectors
with hoses. One port is marked positive (+) and the other negative (–).
Sensing port caps are provided and you should place them over the sens-
ing ports when the meter is not in use.
Check to see that the pointer is at zero each time the meter is put into service.
The zero adjustment screw (C) enables you to make an adjustment. With
the caps still on the ports, use a screwdriver to bring the pointer to zero. It
should continue to read zero whether the meter is lying flat, standing up-
right or is at any position in between, including the position where one end
of the scale is lower than the other.
ARange
Scales
BSensing
Ports
CZero
Adjustment
Screw

4
Range Selector
The Range Selector (A) allows you to switch to one of two velocity ranges
or a static pressure range by means of a switch plate (B).
A switch button (C) is provided for changing the Velometer from use with
a Pitot Probe to use with either a Diffuser Probe or a Static Pressure Probe.
When using the Pitot Probe, turn this button and allow it to spring out; when
using either the Diffuser Probe or a Static Pressure Probe, push the button in
and turn to lock it in position. In this position the switch button slot must be
vertical (aligned with arrows on label) for proper instrument operation.
Do not block switch button during operation.
WARNING
!CAUTION
The Range Selector is provided with a plug-in port (D) which accepts the
various probes and allows you to rotate them 360˚. (+) and (–) ports (E)
are provided for hose connections to the meter.
Depending on your model, your set will include one or two Range Selec-
tors that are identified by red or black lettering. This color coding relates
to the same colored scales on the meter.
Take-Up
Adjustment
Screw
A
Range Selector
BSwitch Plate
CSwitch Button
DPlug-In Port
EPort
Connections
F

5
The Range Selector with the black lettering has the following ranges:
Velocity: 0 to 1250 feet per minute
0 to 2500 feet per minute
Static Pressure: 0 to 1 inches of water (6000AP set)
The Range Selector with red lettering has the following ranges:
Velocity: 0 to 5000 feet per minute
0 to 10,000 feet per minute
Static Pressure: 0 to 10 inches of water
A take-up adjustment screw (F) is provided for tightening the switch plate
(B) which may work loose through normal wear. A noticeable effort to
change the setting of the switch plate will indicate proper tightness.
Pitot Probe
The Pitot Probe is designed to measure the velocity of air in ducts and also
in unrestricted areas such as air intakes at grinding/buffing wheels or ven-
tilation slots at plating tanks. For the procedure to measure duct velocities
see pages 13 and 14; for other applications see page 10.
The air intake (and discharge) for the probe is at (A). The probe should be
held at right angles to the air flow; an arrow at the base of the probe (C)
should point in the direction of the air flow.
The probe is marked in one-inch increments (B) for convenience in posi-
tioning the probe inside ducts.
The probe collar (D) acts as a stop when inserting the probe into the Range
Selector; an O-ring acts as a seal when the connecting leg is inserted into
the Range Selector.
Lo-Flow Probe
The Lo-Flow Probe is designed for measuring velocities below 300 feet
per minute in open spaces; it attaches directly to the meter without hoses.
An arrow (A) on the probe serves as a reminder of the direction you must
orient the probe and the meter when taking measurements.
Refer to page 10 for the proper velocity measuring procedure.
AVelocity
Sensing Port
BScale
CAir Flow
Direction
Indicator
DProbe Collar
EConnecting Leg
AAir Flow Direction Indicator

6
Diffuser Probe
The Diffuser Probe is designed to measure the velocity at diffusers, regis-
ters and grilles. The volume of air being supplied or exhausted can be deter-
minedbymultiplyingthe measuredvelocity timesan airflow factor.*Refer
to page 11 for proper diffuser, register and grille measuring procedures.
Thevelocitysensing port (A)senses thevelocityatthediffuser,register,or grille.
The snap-off fins (B) allow you to accurately position the probe vertically,
horizontally or radially.
The probe collar (C) acts as a stop when connecting the probe to the Range
Selector, and the O-ring acts as a seal.
The connecting leg (D) is inserted into the Range Selector.
* Air flow factors, sometimes known as “K” factors, are generally available from the manu-
facturer of the grille or diffuser.
Static Pressure Probe
The Static Pressure Probe is designed for measuring duct static pressure.
The rubber cap (A) provides a seal around the 1/4" hole (in the duct) where
measurements are to be taken.
The probe collar (B) acts as a stop when connecting the probe to the Range
Selector; the O-ring acts as a seal.
The connecting leg (C) is inserted into the Range Selector.
Refer to page 8 for the proper static pressure measuring procedure.
AVelocity
Sensing
Port
BSnap Off
Fins
CProbe
Collar
DConnecting
Leg
ARubber
Cap
BProbe
Collar
CConnecting
Leg

7
PREPARATION FOR USE
Diffuser Probe
Step 1: Remove sensing port caps.
Step 2: Connect two hoses (C) to sensing ports (B).
Step 3: Select proper Range Selector (D).
Note: For velocities below 2500 feet per minute, use the Range Se-
lector with black letters; for velocities above 2500 feet per minute,
use the Range Selector with red letters.
Step 4: Connect Range Selector (D) to loose ends of hoses (C) that are
already connected to the meter (A) as follows:
For Supply Measurements
Connect the plus (+) sensing port of the meter to the plus (+) sensing
port of the Range Selector, and the minus (–) sensing port of the meter
to the minus (–) sensing port of the Range Selector.
For Return and Exhaust Measurements
Connect the plus (+) sensing port of the meter to the minus (–) sens-
ing port of the Range Selector, and the minus (–) sensing port of the
meter to the plus (+) sensing port of the Range Selector.
Step 5: Insert Diffuser Probe (E) into the Range Selector (D). Push the
Diffuser Probe firmly down until the collar of the probe rests against the
top of the Range Selector.
Step 6: Check position of switch button (Da) on Range Selector (D). It
must be pushed in and turned to latch it in.
Step 7: Check position of switch plate (Db) on Range Selector (D). It must
be positioned for the proper velocity range.
Step 8: Proceed to make necessary velocity measurements; see page 11
for procedures.
Sensing
Ports
AMeter
B
CHose
Db Switch
Plate
Da Switch
Button
EDiffuser
Probe
Range
Selector
D

8
Static Pressure Probe
Step 1: Remove sensing port caps.
Step 2: Connect two hoses (C) to sensing ports (D).
Step 3: Select proper Range Selector (D).
Note: For 0–1" static pressures, use Range Selector with black let-
ters; for 1–10" static pressures, use Range Selector with red letters.
Step 4: Connect the hoses to the Range Selector (D) as follows:
For Positive Pressure Measurements
Connect the plus (+) sensing port of the meter to the plus (+) sensing
port of the Range Selector. Connect the minus (–) sensing port of
the meter to the minus (–) sensing port of the Range Selector.
For Negative Pressure Measurements
Connect the plus (+) sensing port of the meter to the (–) sensing port
of the Range Selector. Connect the minus (–) sensing port of the meter
to the plus (+) sensing port of the Range Selector.
Step 5: Select the proper Static Pressure Probe (E)
Note: For 0–1" static pressures, use the Static Pressure Probe with
black letters. For 1–10" static pressures, use the Static Pressure
Probe with red letters.
Step 6: Insert the Static Pressure Probe (E) into the Range Selector (D).
Push the probe firmly down until the collar of the probe rests against the
top of the Range Selector.
Step 7: Check position of switch plate (Da) on the Range Selector (D).
It must be pushed in and turned to lock it in position.
Step 8: Check position of switch plate (Db) on the Range Selector (D).
It must be to the extreme left.
Step 9: Proceed to make duct static pressure measurements. See page 13
for proper procedure.
AMeter
B
CHoses
Db Switch
Plate
Da Switch
Button
EStatic
Pressure
Probe
Range
Selector
D
Sensing
Ports

9
Pitot Probe
Step 1: Remove sensing port caps.
Step 2: Connect two hoses (C) to sensing ports (B).
Step 3: Select proper Range Selector (D).
Note: For velocities below 2500 feet per minute, use the Range Se-
lector with black letters; for velocities above 2500 feet per minute,
use the Range Selector with red letters.
Step 4: Connect the hoses to the Range Selector (D) as follows: The plus
(+) sensing port of the meter to the plus (+) sensing port of the Range
Selector and the minus (–) sensing port of the meter to the minus (–) sens-
ing port of the Range Selector.
Step 5: Insert the Pitot Probe (E) into the Range Selector (D). Push the
Pitot Probe firmly down until the collar of the probe rests against the top
of the Range Selector.
Step 6: Check position of switch button (Da) on Range Selector (D). It
must be released and left in the out position.
Step 7: Check position of switch plate (Db) on Range Selector (D). It must
be positioned for the proper velocity range.
Step 8: Proceed to make necessary duct velocity measurements. See page
13 for proper procedures.
Lo-Flow Probe
Step 1: Remove sensing port caps.
Step 2: Connect the Lo-Flow
Probe (F) directly to the meter (A)
by placing it onto the sensing ports
(B); no hoses are required. It fits
only one way onto the meter, with
the arrow pointing to the left when
viewing the meter from the front.
Db Switch
Plate
Da Switch
Button
Range
Selector
D
CHoses
A
Meter
B
Sensing
Ports
EPitot
Probe
Lo-Flow Probe F