Education Pack
CALIPERS
Definition
How to read an analogue caliper
Inside jaws
Caliper (EN ISO 13385-1)
"Measuring instrument which gives the evaluation of a
dimensional quantity of an internal or external feature of a
workpiece on the basis of the movement of a slider with a
measuring jaw, moving relative to a measuring scale on a
rigid beam and a fixed jaw."(1)
Slider
Locking screw
Depth measuring rod
Beam
Output connector
The vernier scale is attached to the caliper`s slider. Each division on this scale is 0,02 or 0,05 mm shorter than one
main scale division of 1 mm. This means that, as the caliper jaws open, each movement of 0,02 or 0,05 mm brings the
succeeding vernier scale line into congruence with a main scale line and hence indicates the fraction, in 0,02 or 0,05
mm units, of the main scale division to be counted.
Vernier calipers
Application
Dial calipers
(1)
Main scale
Thumb-roller
Graduation : 0,05 mm
Graduation : 0,01 mm
(1) Main scale reading 4,00 mm
(2) Vernier scale reading 0,75 mm
(1) Main scale reading 16,00 mm
(2) Dial face reading 0,13 mm
Caliper reading
ZERO / ABS button
(2)
(1)
(2)
4,75 mm
Caliper reading
16,13 mm
Caliper with nib style jaws
The wear of the jaws is less than in the case of an of
inside measurement using crossed measuring surfaces.
Note: 0,75 mm (2) is read at the
position where a main scale
graduation corresponds with
a vernier graduation.
ON / OFF button
Outside jaws
Parallax error
1
3
Measuring faces for internal measurement
Coolant Proof Digital Caliper with IP67 degree of
protection according to EN 60529. Dust-proof and
protected against temporary submersion. A wireless
transmitter is connected to the data output to transfer
the measuring results for statistical process control.
2
Vernier scale inch
Measuring faces for depth measurement
Slider
Parallax error is likely to occur whenever two scales are separated by a step (e.g. vernier
and main scale), as illustrated here. In this example, viewing the scale from points 1, 2 and
3 all result in different readings due to the angles involved. Look perpendicularly onto the
scale to get the reading without parallax error.
Point jaw caliper
For measurements on hard to reach spots.
Beam
Abbe’s Principle
Main scale
Clamping device
Vernier scale metric
Conducting an outside measurement by use of a dial caliper.
In a dial caliper, a pinion engaging a rack attached
to the main beam carries a pointer to indicate measurements
on a dial indicator with 0,01 or 0,02 mm scale graduation.
In the case of calipers, the scale and the length
to be measured are parallelly offset.
➞ Breach of Abbe’s Principle!
The tilt error depends mainly on the play between slider and main scale, the
parallel offset between scale and workpiece, and the measuring force.
In principle, this error cannot be fully avoided.
Measuring faces for external measurements
Measurement examples
Outside measurement
A workpiece to be measured should be placed as close to the beam as possible.
Depth measuring rod
Sliding (measuring) jaw
Fixed jaw
The length to be measured (workpiece) and
the material measure (scale) should always
be in true alignment.
Inside measurement
Measuring faces
Point Caliper
The jaws fit into very small grooves.
Small hole measurement
Due to the thickness and separation of caliper knife-edge jaws, the line between
the jaw contact points is offset relative to the scale axis when measuring a hole diameter.
The table below shows typical correction values for against offset.
Calibration
Gauge blocks or gauge block combinations should
be applied for caliper calibration. In accordance with to EN ISO
13385-1, the following gauge blocks and reference gauges are
suitable for caliper with 150, 200, 300 mm range:
Measuring faces
Depth measurement
H
Step measurement
Measuring faces
ød
øD
A lightweight digital caliper that employ carbon fiber
reinforced plastics can be used especially where large
dimensions are measured
(1)
Measuring faces
øD
ød
Δd
H
= Diameter of the hole
= Measured diameter
= Measurement error (øD – ød)
= Clearance and surface (offset)
Set allocation
Correction to be added for øD = 5 mm
H
0,3
0,5
0,7
Δd
0,009 0,026 0,047
10 mm
140 mm
Setting Ring ø 5 mm
Pin Gauge ø 15 mm
40 mm
180 mm
270 mm
EN ISO 13385-1
Mitutoyo Europe GmbH · Borsigstr. 8 - 10 · 41469 Neuss · Germany · P +49 (0) 21 37 - 102-0 · info@mitutoyo.eu · www.mitutoyo.eu
© MITUTOYO/D 1214 PRE9007(2)_1
The term „degree of protection“ describes the protection
provided by a device or the device interior against direct
contact as well as against penetration of foreign matter,
such as objects, dust or water.
Contact and foreign
matter protection
Probe testing
For this, balls or bars of different diameters (depending
on the degree of protection) are pressed against each
opening of the device housing. The object must not
penetrate the inside of the device through any opening
with its full diameter.
First digit:
Degrees of protection for contact
and foreign matter protection
Digit
Designation
Explanation
0
No protection
No special protection to prevent infiltration by solid foreign
objects.
1
Protection against
very large solid
foreign objects
Protection against solid foreign objects greater than 50
millimeters in diameter.
Protection against
large solid foreign
objects
Protection against solid foreign objects greater than 12,5
millimeters in diameter.
3
Protection against
medium-sized solid
foreign objects
Protection against solid foreign objects greater than 2,5
millimeters in diameter.
4
Protection against
Protection against foreign objects greater than 1 millimeter in
small foreign objects diameter.
5
Dust-protected
Complete protection against dust is not necessary, but prevention
of infiltration must be sufficient to ensure that the
functioning and safety of the device are not impaired.
6
Dust-tight
Complete protection against dust infiltration.
2
Dust chamber testing
Talcum powder is placed suspended in a closed chamber
for 8 hours. The specifications of the IP protection class
5 or 6 are fulfilled when there is no sign of functional
impairment and/or dust infiltration.
Water protection
Drip, spray and splash water test
The IP protection class 1 - 4 tests are conducted
using drip, spray and splash water aimed
in different directions.
Education Pack
DEGREE OF PROTECTION: IP CODE
Second digit: Degrees of protection
against ingress of water
Digit
Designation
Explanation
0
No protection
No special protection to prevent water infiltration.
1
Protection against
vertically falling
water drops
Water dripping vertically onto the device must not cause any
damage.
2
Protection against
Water dripping vertically onto a device tilted to an angle of up to
water dripping at an 15° from the vertical must not cause any damage.
angle
3
Protection against
spray water
Protection against sprayed water landing on the device at any
angle up to 60° to the vertical line.
4
Protection against
splash water
Water splashing against the device from any direction must not
cause any damage.
5
Protection against
water jets
A jet of water aimed at the housing from any direction must not
cause any damage. (3 min. and 12,5 L/min.)
6
Protection against
powerful water jets
A powerful jet of water aimed at the device from any direction
must not cause any damage. (3 min. and 100 L/min.)
7
Protection against
temporary
immersion
When the device is temporarily (30 min.) immersed 1 meter deep
in water, the water must not enter the device in any sufficient
quantity as to cause damage to the equipment.
8
Protection against
continuous
immersion in
water
The device is suitable for continuous submersion in water. The
conditions must be individually discussed and agreed upon
between the manufacturer and the user, but must exceed the
specifications of IP 7.
Outside Micrometers
Inside Measuring Instruments
Mitutoyo Europe GmbH · Borsigstr. 8 - 10 · 41469 Neuss · Germany · P +49 (0) 21 37 - 102-0 · info@mitutoyo.eu · www.mitutoyo.eu
Calipers
Test setup for the IP class
protection test at Mitutoyo
Mitutoyo quality assurance test
Compliance with the IP code is verified by a third party
after manufacture of the measuring device by means of
testing in a pressurized chamber.
A test vessel and reference vessel are used to ensure
that devices with faulty seals are identified immediately
when the pressure drops in the test vessel. This test
ensures compliance with IP protection specifications.
TÜV certification
The resistance to stress arising from prevailing working conditions is defined by ingress protection
(IP) classes. These degrees of protection are, in turn, indicated in standards (DIN EN 60529), whereby
a combination of two digits specifies the level of protection.
The high stress levels according to IP degree of protection of the length measuring devices are confirmed
by corresponding test certificates issued by TÜV Rheinland Group following a series of in-depth tests.
Interpreting IP protection classes
correctly
Both high IP grades and additional measures and
certifications should not be misunderstood as alicense
to careless or even negligent treatment of the
equipment. No matter how high the quality of the
hand-held measuring device it will eventually suffer
damage if not treated with the proper care throughout
its service life. According to IEC 60529, IP protection on
its own only describes the behavior of an object in the
conditions defined by the standard. How long, and how
reliably a digital hand-held measuring device performs
faultlessly in severe working conditions is largely,
ultimately, and literally in the hands of the users.
Mitutoyo hand-held measuring devices with extremely high IP protection classes
Water jet test
When conducting tests to fulfill IP degree of protection
class 5 or 6, a water jet coming from a spray nozzle is
aimed in all possible directions (with a different flow rate
depending on the protection class).
Immersion testing
IP-code x7 requires
complete immersion
of the test specimen
in a 1 meter deep
water basin.
Indicators
Build In Calipers
Linear Scale
© MITUTOYO/D 1214 PRE9007(2)_2
Education Pack
HEIGHT GAUGE
Definition
Height Gauge (EN ISO 13225)
"Measuring instrument in which a slider with
a measuring stylus moves relative to a measuring
scale on a beam and in which this motion is along
a single vertical axis nominally perpendicular
to a reference plane on the instrument base."(1)
Main pole
Sub pole
Column
Standard
Correct operation
EN ISO 13225
Geometrical product specifications (GPS) – Dimensional
measuring equipment:
Height gauges – Design and metrological characteristics.
Lifting the base off the reference surface
When setting the scriber height from a workpiece
feature, the base may lift from the surface plate if
excessive downwards force is used on the slider. For
accurate setting, move the slider slowly downwards.
Correct setting is accomplished when the scriber is
felt to lightly touch as it moves over the edge
of the surface.
How to read the scale
Application
Locking device
Feed handwheel
Power ON/OFF button
Touch-trigger probe
Vernier height gauge
Zero set button / ABS (Absolute) button
Touch probe connector
(2)
Hold / data button
Preset mode, ball diameter
compensation mode button
Number up/down button, presetting
Direction switch / digit shift
button, presetting
Graduation : 0,02 mm
(1) Main scale reading
(2) Vernier scale reading
79,00 mm
0,36 mm
Height gauge reading
79,36 mm
Multifunction
1D and 2D Height Gauge
Features such as height, distance, diameter and
maximum/minimum distances can be measured with
these instruments. Automatic running of pre-learnt part
programms is possible and a pneumatic floating system
makes it easy to move the gauge on a granite plate.
Measuring face
Height measurement with the measuring
face of the scriber.
A two-directional probe for height gauges with
column design. It guarantees a constant measuring
force for height measurement. The probe automatically
compensates the stylus ball diameter to allow direct
measurements of inside and outside widths.
(1)
Fine adjuster for main scale
Beam
Optional accessories for
1D and 2D height gauges
Do not over-extend the scriber arm
The scriber arm should not be extended longer than
necessary. As with the caliper measurement, the line
of measurement must be as close to the main scale
as possible in order to minimize Abbe's error. It is
also important to keep an appropriate and constant
measuring force as height gauges are not provided
with a limiting device.
Main scale
Dial test indicator used with a height gauge to measure
a reference plane.
Slider
Varying probes enable the height gauge to measure many
different features of a workpiece.
Fine-adjustment
device
Vernier scale
Locking devices
h
Fixing device
Probe extension
Measuring and scribing stylus
Measuring face
Instrument base
MAX – MIN
MAX
MIN
Guiding face
Diameter measurement with a 1D height gauge.
(1)
Instrument-base reference base
Height and diameter
measurement
EN ISO 13225
MAX/MIN/RANGE
measurement
h
Example: Effect of measuring point position.
With h=150 mm, the error is 1,5 times
larger compared to h=100 mm.
A dial-type or digital indicator can be used
to measure straightness or perpendicularity
with a vertical height gauge.
MAX – MIN
MAX
MIN
Mitutoyo Europe GmbH · Borsigstr. 8 - 10 · 41469 Neuss · Germany · P +49 (0) 21 37 - 102-0 · info@mitutoyo.eu · www.mitutoyo.eu
© MITUTOYO/D 1214 PRE9007(2)_3