SKF TKRT 21 User manual

Instructions for use
SKF TKRT 21

3EN
Safety precautions ...............................................................................4
EU Declaration of Conformity ...............................................................6
1. Instructions for use........................................................................7
2. Technical data..............................................................................10
3. Getting started: ...........................................................................11
4. General usage..............................................................................11
4.1 Rotational Speed ..................................................................................12
4.1.1 Laser mode................................................................................13
4.1.2 Contact mode ............................................................................14
4.2 Linear Speed.........................................................................................14
4.3 Distance .................................................................................................15
4.4 Settings .................................................................................................16
5. Symbols.......................................................................................17
6. Troubleshooting...........................................................................18
7. Spare parts and accessories.........................................................18
Table of contents
Original instructions

4 EN
WARNING LASER RADIATION
P
=1mW l = 650nm IEC 60825-1:2014
DO NOT STARE INTO BEAM
CLASS 2 LASER PRODUCT
READ THIS FIRST
Safety precautions
Read this instruction for use fully. Follow all safety precautions to avoid
personal injury or property damage during equipment operation.
SKF cannot be responsible for damage or injury resulting from unsafe
product use, lack of maintenance or incorrect equipment operation. In case
of any uncertainties as regards the use of the equipment contact SKF.
This device is used for inspecting the movement of rotating and vibrating
objects. It may only be used in accordance with these instructions.
The device must not be opened. Modifications to the device are not
permitted. The manufacturer shall not be liable for damage resulting from
incorrect use or use contrary to the intended use. Warranty claims will also
be invalidated in this event.

5EN
WARNING:
Risk of injury!
• Moving objects should not be approached without care.
• Do not touch moving objects directly, under any circumstance.
• The device may not be used in potentially explosive areas.
• Laser class 2
• The SKF Tachometer TKRT 21 is fitted with a class 2 laser. This is located
at the front of the device.
• The laser beam can damage eyes.
• For this reason, do not stare directly at the laser beam and never direct it
at people or animals.
• Wavelength: 650 nm, output: 1 mW.
Warranty void!
• Do not expose the equipment to rough handling or heavy impacts.
• Always read and follow the operating instructions.
• Opening the housing of the instrument may result in hazardous
mishandling and voids warranty.
• The equipment should not be used in areas where there is a risk
for explosion.
• Do not expose the equipment to high humidity or direct contact with
wa ter.
• All repair work should be performed by an SKF repair shop.
Correct disposal!
• =• The electronic components in the device contain environmentally
harmful substances.
They must be disposed of in accordance with the environmental
regulations in the country of use.
NOTE:
• Suitable for use in residential, commercial and industrial area.

6 EN
EU Declaration of Conformity
TKRT 21
We, SKF MPT, Meidoornkade 14, 3992 AE Houten, The Netherlands
herewith declare under our sole responsibility that the products described
in these instructions for use, are in accordance with the conditions of the
following Directive(s):
EMC DIRECTIVE 2014/30/EU
and are in conformity with the following harmonized standards:
EN 55032:2015 (Limit class B) – Radio interference characteristics
EN 61326-1:2017 – Immunity characteristics
EN 61000-4-2:2009 – Electrostatic discharge immunity test (ESD)
EN 61000-4-3:2006+A1:2008+A2:2010 – Radiated, radio-frequency
electromagnetic field immunity test
EN 61000-4-8:2010 – Power frequency magnetic field immunity test
EN 301 489-1:2019-11 – Immunity characteristics
EN 301 489-17:2017-02 – Immunity characteristics
The laser is classified in accordance with the EN 60825-1:2014
EU RoHS DIRECTIVE (EU) 2015/863 and the following harmonized standard:
EN IEC 63000:2018: Technical documentation for the assessment of
electrical and electronic products with respect to the restriction of
hazardous substances
Houten, The Netherlands, December 2020
Mrs. Andrea Gondová
Manager Quality and Compliance

7EN
1. Instructions for use
These operating instructions are an integral part of the device. They must be
stored in an easily accessible location and passed on to subsequent users.
Ask your supplier if there is something you do not understand.
WARNING:
Read the operating instructions thoroughly and follow the instructions
provided. These operating instructions contain important information about
installing, starting up and operating the tachometer.
Pay particular attention to the safety information and warnings to prevent
injuries and product damage.
The manufacturer reserves the right to continue to develop this device
without documenting all developments. Your supplier will be pleased to
inform you as to whether these operating instructions are current.
Content of the box:
• Tachometer: SKF Tachometer TKRT 21
• Contacts: 2 cone tips and 1 wheel 6”
• Operating instructions
• 2 batteries AA (all types, rechargeable too)
• Case
Description:
A- ON OFF Button
B- Batteries compartment: 2 batteries AA must be used
C- Laser out / Connector
D- Accessories

8 EN
B
C
A
D
Fig. 1 – Tachometer SKF TKRT 21
Indication of 4
different modes
Selected mode
SKF logo
Input laser or
contact
Direct access
button function
General aspect of the device
Battery status
Value (like here
primary unit)
Chosen mode (from
direct access button)
Direct access
button function
Fig. 2 – Wireframe

9EN
1. 2.
3.
1. Direct access button left
2. Direct access button right
3. Direct access button center
Fig. 3 – Buttons

10 EN
2. Technical data
Designation TKRT 21
General
Low battery indicator Yes
Auto switch off Yes
Measurement
Optical modes rpm and Hz
Contact modes rpm and Hz, meters, feet, inch, per min and per sec
Speed capture feature Maximum, minimum or average rate
Linear Speed Meters, feet, inch, per min and per sec
Optical Measurement
Rotational speed range 1 to 99999 r/min
Accuracy ±0.01% of reading ±1 digit
Measuring distance 25 mm to 1200 mm (1 in - 47 in)
Angle of operation ±30°
Laser sensor built-in class 2 laser
Contact Measurement
Rotational speed range Max. 20000 rpm for 36000 sec
Accuracy ±0.1% of reading ±1 digit
(>120 rpm)
Contact adaptors Included with removable cones & wheel 6”
Power source 2 x AA batteries, rechargeable ones can be used
Run time ca. 12 h
Display LCD
Display update Continuous
Controls Direct selector switches
Housing material ABS (plastics)
Product dimensions 295 × 70 × 38 mm (11.6 × 2.8 × 1.5 in)
Case dimensions 260 × 85 × 180 mm (10.2 × 3.3 × 7.1 in)
Unit weight 270 g (0.6 lb)
Total weight (incl. case) 850 g (1.9 lb)
Operating temperature 0 to 40 °C (32 to 104 °F)
Storage temperature –20 to +45 °C (–4 to +113 °F)
Type of protection for
indication only
IP 40

11EN
3. Getting started:
• Unscrew the battery compartment screw
• Insert all two AA batteries respecting the polarity
• Close the lid and tighten the screw.
• Start the instrument by pressing the red ON/OFF button
Anytime when the screen below is displayed, press any button to start
measuring speeds or distances. The device will be ready to start measuring,
with the laser or with the contact accessories. For this reason, do not direct it
at people or animals.
The device will start at the function that was set most recently, as well as the
last units used.
Please follow the steps below when setting up the device:
Direct the device at a moving object and use the desired mode: measuring
speeds or distances.
4. General usage
The tachometer offers four different menus to operate it. By pressing the
left button (button 1), the tachometer moves from one menu to the next.
Symbol Name Description
Rotational speed Rotational speed menu with the laser or with
contact tips.
The Speed mode is activated automatically
when contact or laser signal is detected.
Linear speed Linear speed menu to be used only with wheels.
Make sure to select the right wheel size in order
to have the right unit.
Distance Distance menu to be used only with wheels.
Make sure to select the right wheel in order to
have the right unit
Setting Menu to change the settings of the tachometer
to the preferences of the operator.
The first time you switch ON the tachometer, you will be asked to select the
units you prefer: metric or imperial. You can always change it later in the
setting menu.

12 EN
4.1 Rotational Speed
After starting the instrument, the first menu is rotational speed, in RPM or
in Hz, and these units can be chosen in the Settings menu. Speed can be
measured both using laser (and reflective tape), or using the available tips
included in the case with the TKRT 21 Tachometer. The Tachometer detects
automatically if the laser is being used or if a tip is being used. When a tip is
used, the laser is not activated.
The speed measurement can be used in two different ways:
A. Short press (< 0.5 s) on button “measure” (3) activates the laser and
starts a continuous measurement. Another short press on (3) turns the
measurement off.
B. Long and continuous press (> 0.5 s) on button “measure” (3) activates
the laser as long as the button is pressed.
Fig. 4 – Example
• Units can be changed in the Settings.
• When measuring, a dot is used to indicate decimals.
• Measuring time appears when a measurement starts,
when a signal is detected from the laser or a tip.
• Laser icon is displayed when the laser is used to measure a speed.

13EN
During the speed measurement, the tachometer records the measured speed
values. After the speed measurement, the statistics of the measurement are
available (min, max and average). You can toggle between these values by
pressing the right button “next” (2).
The Mode can be changed by pressing the left button “mode” (1).to switch
from Rotational Speed, Linear Speed, Distance and Settings.
4.1.1 Laser mode
The laser mode allows the tachometer to determine the speed remotely. The
laser requires a reflective surface mounted on the rotating machine such as
the supplied reflective tape.
Using the laser helps to quickly determine the speed of the rotating object
and record the measured speeds.
A laser symbol on the screen indicates that the laser is active.
WARNING:
Never point the laser at people, animals or mirror surfaces. The laser beam
can damage eyes.
In order to make a proper measurement, attach small reflective target to
machine shaft (typically 6 mm x 25 mm).
• Start machine and point the tachometer towards the target.
• Press and/or hold the centre button “measure” (3) to suit application
and/or hold it continuously during measurement.
• Aim laser beam onto target
• Read off rpm or Hz, pressing “stop” (3) or releasing button (3) will hold
last reading.
• Last rpm or Hz reading will be held in display.
• After the measurement, the statistics of the measurement are available
(min, max and average). You can toggle between these values by
pressing the right button “next” (2).

14 EN
4.1.2 Contact mode
The tachometer is supplied with different tips for different purposes:
male or female conical end.
Fit contact adapter into the tachometer and ensure a good click connection.
• Start machine and make clean contact with the recess in shaft end.
• Contact the shaft end via the rubber cone, ensure a steady firm pressure
is applied and that the instrument is in line accurately with the machine
shaft.
• Press and/or hold centre “measure” button (3) as required & read speed.
• Releasing the button pressing “stop” button (3) will hold the last reading.
• Last rpm or Hz reading will be held in display.
• After the measurement, the statistics of the measurement are available
(min, max and average). You can toggle between these values by
pressing the right button “next” (2).
4.2 Linear Speed
• Fit contact wheel 6”, or one of the other optional wheels (12”or 0,1m) as
chosen for user’s application.
• Press “measure” or keep the “measure” button pressed, now place the
contact wheel on the moving surface and read the linear speed, ensure
wheel is vertical to the moving surface.
• Press “stop” or release the “stop” button to stop the measurement, the
tachometer will then hold the last reading on the display.
• After the measurement, the statistics of the measurement are available
(min, max and average). You can toggle between these values by
pressing the right button “next” (2).
• The instrument retains selected measurement mode for further linear
measurements after switching off the tachometer, until used to a
different mode.
Units can be changed in the
settings
Linear speed units:
Feet per second (ft/sec)
Feet per minute (ft/min)
Inch per second (in/sec)
Inch per minute (in/min)
Meter per second (m/sec)
Meter per minute (m/min)
Available wheel sizes:
0.1m
6 inch
12 inch
Units and wheel size are determined in the settings menu
When measuring a dot is used
to indicate decimals
Note that the measuring time only
appears when a measurement is
started and a signal is received
Icon shows which wheel to use
(determined in the settings menu)
Fig. 5 – Units and wheels

15EN
4.3 Distance
• Fit contact wheel as chosen for user’s application.
• Press “measure” or keep the “measure” button pressed, now place the
contact wheel on the moving surface and read the linear rate, ensure
wheel is vertical to the moving surface.
• Press “stop” or release the “stop” button to stop the measurement, the
tachometer will then hold the last reading on the display.
• The instrument retains selected measurement mode for further distance
measurements after switching off the tachometer, until used to a
different mode.
The workflow of the Distance mode is the same as the Linear Speed mode
but with different units.
During the distance measurement, the tachometer records the total
measured distance value. After the measurement, the final distance is
displayed.

16 EN
4.4 Settings
Fig. 6 & 7 – Settings
Different settings can be scrolled through by using the centre button
(Button 3). Change values of the settings by pressing direct access buttons.
Name Options Description
Rotational
Speed
Rpm / Hz Select the rotational speed unit, 1 Hz = 1
round per second.
Linear
Speed
in/sec - in/min
ft/sec - ft/min
m/sec - m/min
Select the linear speed unit,
metric or imperial
Distance inch - ft - m Select the distance unit, metric or imperial
Wheel size 0.1 m - 6 inch -
12 inch (option)
Select the required wheel for user’s
application
Display
Brightness
20-40-60-80-100 % Change the display brightness
Auto off off / 5 min / 10 min Select if the tachometer should turn off
automatically and after how many minutes

17EN
5. Symbols
low battery
laser activated
tip
wheel
Rotational speed menu icon
Linear speed menu icon
Distance menu icon
Settings menu icon
Fig. 8 – Symbols

18 EN
6. Troubleshooting
Problem Solution
Display is dirty Use a wet cotton swab to clean the display area and a clean,
dry cotton cloth to remove any water remains.
Do not wash the display with too much water or solvents.
Menu is frozen Remove the batteries and wait for 1 minute before placing
them back.
Start the device and check that everything works.
Too short
operating time
Replace batteries with new batteries.
Check if another brand offers better performance.
Do not store the tachometer in very hot or cold
environments. Turn on the auto off function to conserve
battery power.
7. Spare parts and accessories
Designation TKRT 21
TKRT RTAPE Reflective tape
TKRT TIPS Wheels and Cones set
TKRT WHL12 12” wheel
TKRT 21-CA Toolcase with inlay for TKRT 21
TDTC 1/A General toolcase without inlay, size A

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MP5508 EN · 2021/02
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ensure the accuracy of the information contained in this publication but no liability can be
accepted for any loss or damage whether direct, indirect or consequential arising out of the
use of the information contained herein.