SKF PHL FM 10/400 User manual

SKF Belt Frequency
Meter user manual
User manual box edition

General safety tips
Safety rst – read and understand this manual before
operating the SKF Belt Frequency Meter.
Never use your SKF Belt Frequency Meter on moving belts.
Switch on and isolate any
belt drive system prior to
taking tension measurements
or attempting any other
installation work.
Do not drop the meter or
subject either the meter or
the optical sensor to other
sharp impact.
Do not put water, solvents
(including cleaning solutions)
or any other liquid on the
unit. Clean meter and
sensor with dry cotton cloth.
Do not pull on sensor cord.
Disconnect sensor from
meter by grasping the
connector grip only.
Do not leave the unit in
places that are humid, hot,
dust lled or in direct
sunlight.
Hint: When SKF Belt
Frequency Meter is not used
for a while, remove batteries
and store unit in the case
provided.
Do not use your SKF Belt
Frequency Meter in any
potentially explosive
environment.
Do not disassemble or
attempt to modify either the
meter or the sensing head.

Table of contents
1.0 Device description 4
2.0 Quick start 5
3.0 Functions
3.1 Keys 6
3.2 Audio/ visual display 7
3.3 Optical sensor 8
3.4 Battery condition 9
3.5 Charging batteries 10
4.0 Setup & use 11
5.0 Operating tips 13
6.0 Meter range 14
7.0 Calibration
7.1 Spot check 15
7.2 Annual certication 16
8.0 Technical specication 17
9.0 Useful formulae and conversions 18
Appendix
1.0 Theory of operation 19
2.0 Limited warranty 20
3.0 Belt mass constants 21
page

4
1.0 Device description
The SKF Belt Frequency Meter is a two component system consisting of a hand-held meter
attached to an optical sensor via an electronic cable. The sensor uses an infrared beam to detect
the vibration of a belt strand and sends a signal to the meter. (The sensor includes an LED that
produces an orange light beam to help aim the invisible infrared ray.) Comparing this input to
the vibration of a quartz crystal, the meter computes the natural frequency of the belt. The result
is shown in the display window as hertz (oscillations per second). The internal programming of
the meter is also able to report the belt tension in units of force (either newton or pounds-force)
provided the operator has entered the belt mass and span length using the manually operated
key pad.
The meter operates on four “AA” batteries. Battery life is approximately 20 hours. The battery
compartment is accessible at the back of the meter. This manual, a tuning fork for checking
calibration and a storage case are included with the complete kit.
LED aiming
beam
Optical sensor
see section 3.3 Plug in
sensor cable
Display
window see
section 3.2
Keypad see
section 3.1

5
2.0 Quick start
1. Plug in sensor
2. Press
to switch
meter on
3. Aim sensor at belt, gap
5 to 25 mm
4. Tap or
pluck belt
5. Read belt
frequency (Hz)

6
3.0 Functions
3.1 Keys
ON/OFF
SPAN
(m)
MASS
(kg/m)
UP
(Hz/N)
DOWN
(Lbs)
MEM 1
MEM 2
MEM 3
This key switches the meter on or off. If the meter is on and sits idle for more
than 3 minutes, it automatically switches off to preserve battery life. When the
meter is rst switched on a battery check is made see Section 3.4 for a description
of the visual and audible low battery signal.
This key is used to enter the belt span length. The span key is held down while
the UP or DOWN keys are used to set the belt span in metres. Releasing the
SPAN key results in an audible beep to indicate the setting has been accepted.
Pressing the SPAN key alone, shows the current setting.
This key is used to enter the belt mass. The mass key is held down while the
UP or DOWN keys are used to set the belt mass in kg/m. Releasing the MASS
key results in an audible beep to indicate the setting has been accepted. Pressing
the MASS key alone shows the current setting.
Important Note:
Belt span and belt mass are required entries if tension results in force units (N or lbf)
are desired. Entries must be in SI units (m and kg/m)
This key has two functions. The rst is to increase either the SPAN or MASS
parameters when used in conjunction with these keys. The second use is to
toggle between the Hz and the newton measurement modes.
This key has two functions. The rst is to decrease either the SPAN or MASS
parameters when used in conjunction with those keys. The second use is to
toggle between the Hz and the pound measurement modes.
The memory keys allow up to 3 sets of belt parameters to be stored in the
meter registry. Pressing the MEM 1 key recalls the rst set of belt parameters
and likewise for MEM 2 and MEM 3.
To store the belt parameters to a key, the belt span and mass parameters must
rst be entered and then immediately after release of either the SPAN or MASS
keys the appropriate MEM key should be pressed. Two beeps indicate that the
parameters have been successfully assigned to the key.

7
3.2 Audio/visual display
The SKF Belt Frequency Meter is an interactive tool. It provides both visual and audible
communication with the operator. Each signal or combination of signals has a meaning. While
all these signals are discussed in other sections of this manual, a compilation of all the available
signals will be presented here.
Generally visual signals alone give measurement results while audible signals, either alone or in
combination with a visual signal, indicate some operational step.
Tension displayed
in newton
Frequency mode,
results displayed as hertz
Tension displayed
in pound-force.
Visual measurement
results
A line segment will appear to indicate the
units assocaited with the number displayed
Audible signals
Signal When Means
One Beep Upon release of “Span” key Input accepted
One Beep Upon release of “Mass” key Input accepted
One Beep While sensor is aimed at vibrating belt Measurement taken
Two Beeps Upon pushing “Memory” key after
releasing “Span” key
Span data has been stored
Upon pushing “Memory” key after
releasing 'Mass' key
Mass data has been stored
Four Beeps Combined with “0000” N display Newton result is out of range
Combined with “0000” lb display Pound result is out of range
After pushing “On” key combined with
“zero” countdown
Low battery condition
N
Hz
lbs
N
Hz
lbs
N
Hz
lbs

8
3.3 Optical sensor
The sensor uses an invisible infrared beam to
detect vibrations of the belt. A narrow angle
orange LED generated beam is provided to guide
the aiming of the sensor.
The very best signal from the belt is seen when
the sensor is held perpendicular to the belt at the
centre of the span at 9,5 mm (3/8 in) distance.
When physical restrictions are present, it is possi-
ble to get useable readings with the sensor up to
50 mm (2 in) distance from the belt and/or tipped
up to 45° from perpendicular.
It is possible to take measurements from the
edge of the belt. The toothed side of a belt is
equally acceptable as a target for the sensor.
The sensor LEDs should be kept clean by wiping
with a soft cotton cloth. Solvents are never to
be used.

9
3.4 Battery condition
When the SKF Belt Frequency Meter is rst switched on, a battery condition check is automatically
performed. A low battery condition is signalled both visually and audibly. The display window will
ash an array of zeros, starting with four and progressing to only one. There will be an audible
signal of four “beeps” as the display changes
If these signals are seen and heard, batteries should be replaced. Batteries are accessed through
the removable cover on the back of the meter. New batteries should be inserted within 30
seconds of removal of old batteries. Taking longer risks loss of any data stored by the memory
keys. Batteries are expected to provide approximately 20 hours of continuous operation before
replacement is required.
N
Hz
lbs
N
Hz
lbs
N
Hz
lbs
N
Hz
lbs
BEEP
BEEP
BEEP
BEEP

10
3.5 Charging batteries
Do not charge batteries with the sensor head attached to the meter. Do not attempt to use the
meter while batteries are being charged. Damage to the optical sensor could result.
The SKF Belt Frequency Meter is compatible with user supplied rechargeable batteries and
charging unit. A convenient 3,5 mm, positive center charging socket is located on the bottom end
of the meter body adjacent to the sensor cable plug-in port.
Batteries: 1 300 mAh minimum (user supplied)
Charging unit: 12 to 15 volt DC output (user supplied)
Connection: 3,5 mm positive tip mini plug/socket
The built in circuit of the meter controls the charging current. Charging current is internally
limited to 100 mA. Charging time is typically 12 to 14 hours for a full charge.
You may turn the unit on while charging. The meter’s software will then signal that the batteries
are charging. The display window will ash an array of zeros, starting with only one and pro-
gressing to four. There will be an audible signal of four 'beeps' as the display charges.
Suitable rechargeable batteries and charger may be obtained directly from IDS.