Length Gauges

05/2021

Contents

Length gauges from HEIDENHAIN
provide high accuracy over long measuring
ranges. They are also robust and practical.
They can be used in a wide range ofapplications, including production metrology,
multi-gauging fixtures, measuring equipment
monitoring, and position measurement.

Length gauges: applications and products
Areas of application

4

Length gauges from HEIDENHAIN

6

Overview of length gauges

8Technical features and mounting information
Measuring principles

10

Measuring accuracy

12

Mounting

16

Setup

17

Gauging force and plunger actuation

19

Specifications

Accuracy

Measuring range

Absolute length gauges

HEIDENHAIN-ACANTO

±1 µm
±2 µm

12 mm
30 mm

22

Incremental length gauges

HEIDENHAIN-CERTO±0.1 µm; ±0.03 µm*±0.1 µm; ±0.05 µm*

25 mm
60 mm

24

HEIDENHAIN-METRO±0.2 µm

12 mm
25 mm

26

HEIDENHAIN-METRO±0.5 µm
±1 µm

60 mm
100 mm28

HEIDENHAIN-SPECTO

±1 µm

12 mm
30 mm

30

Length gauges withlow measuring forces±0.2 µm
±1 µm

12 mm

32

Accessories

34

Measuring contacts, switch boxes, coupling
Gauge stands, ceramic suction plate, diaphragm compressor

For HEIDENHAIN-CERTO

36

Cable release and gauge stands

For HEIDENHAIN-ACANTO, HEIDENHAIN-METRO,and HEIDENHAIN‑SPECTO

38

Further information
Signal converters

40

Calibration according to DAkkS

42

Related documents

43

Further information:
This brochure supersedes all previous
editions, which thereby become invalid.
The basis for ordering from HEIDENHAIN
is always the brochure edition valid when
the order is placed.

2Standards (ISO, EN, etc.) apply only
where explicitly stated in the brochure.

For detailed descriptions of all available
interfaces, cables, and connecting
elements, as well as general electricalinformation, please refer to the Interfacesof HEIDENHAIN Encoders and theCables and Connectors brochures.

* After linear length-error compensation in the evaluation electronics

Areas of application
In quality assurance

In production metrology

Metrology and production
controlMulti-gauging fixtures
Multi-gauging fixtures require durable length
gauges with small dimensions. They should
also have relatively large measuring rangesof several millimeters with consistent linear
accuracy in order to simplify the constructionof inspection devices—for example byenabling the construction of one device forseveral masters. A large measuring length
also provides benefits in master production,
because simpler masters can be used.

Length gauges from HEIDENHAIN play arole in incoming goods inspection, fastdimension checking during production,
statistical process control in production or
quality assurance, or in any application
where fast, reliable and accurate length
measurement is required. Their large
measuring lengths are a particular advantage:
whether the part measures 5 mm or 95 mm,
it is measured immediately with one andthe same length gauge.
Whatever the application, HEIDENHAIN has
the appropriate length gauge for the required
accuracy. The HEIDENHAIN-CERTO length
gauges offer a very high accuracy of±0.1 µm/±0.05 µm*/±0.03 µm* forextremely precise measurement. Length
gauges from the HEIDENHAIN-METRO
program have accuracy grades as fine as±0.2 µm, while the HEIDENHAIN-SPECTO
length gauges, with ±1 µm accuracy, offer
particularly compact dimensions.

Thanks to their small dimensions, theHEIDENHAIN-ACANTO absolute length
gauges, like the HEIDENHAIN-SPECTO
incremental length gauges, are speciallydesigned for multi-gauging fixtures. They
feature accuracy grades of down to ±1 μm
over measuring ranges up to 30 mm. Morestringent accuracy requirements of down
to ±0.2 µm can be met with similarlycompact HEIDENHAIN-METRO length
gauges.
Workpiece inspection* After linear length-error compensation in
the evaluation electronics

Gauge block calibration andmeasuring device inspection

4

Unlike inductive gauges, HEIDENHAIN
length gauges provide stable measurement
over long periods—eliminating recalibration.

Testing station for flatness inspection

Tolerance gauging of semifinished products

Position measurement
Length gauges from HEIDENHAIN are also
ideal for position measurement on precisionlinear slides and X-Y tables. Working withmeasuring microscopes, for example,
becomes much easier thanks to the digital
readout and the flexible datum setting.

The regular inspection of measuring
equipment called for by standards, and theinspection of gauge blocks in particular,
necessitate a large number of reference
standard blocks if the comparative measure­ment is performed using inductive gauges.
The problem is the small measuring range
of inductive gauges: they can measurelength differences of only up to 10 µm.
Length gauges, which offer large measuring
ranges together with high accuracy, greatly
simplify the calibration of measuring
devices required to ensure traceability.
The length gauges of the HEIDENHAINCERTO product portfolio with measuring
ranges of 25 mm with ±0.1 μm/±0.03 μm*
accuracy and 60 mm with ±0.1 μm/±0.05 μm* accuracy are especially well
suited for this task. They permit asignificant reduction in the required
number of reference standard blocks, andrecalibrating becomes much simpler.

Inspection of styli

Here, length gauges from the HEIDENHAINMETRO and HEIDENHAIN-SPECTO
program come into use with large measuring
ranges of 30 mm, 60 mm or 100 mm
at consistently high accuracy grades of±0.5 μm or ±1 μm.
In this application as a linear measuring
device, the length gauge’s fast installationin accordance with the Abbe measuring
principle by its clamping shank or plane
mounting surface is of special benefit.

Calibration of gauge blocks

Position measurement on an X-Y table for lens mounting

5

Length gauges from HEIDENHAIN

Length gauges from HEIDENHAIN featurehigh accuracy over long measuring ranges.
These sensors are used whenever lengths
need to be measured with speed,
reliability, and accuracy.

Long measuring ranges

HEIDENHAIN length gauges are available
for measuring ranges of 12 mm, 25 mm,
30 mm, 60 mm, or 100 mm. This lets you
measure a wide variety of parts with asingle measuring setup without frequently
changing cost-intensive gauge blocks ormasters.

High accuracy

The high accuracy of HEIDENHAIN length
gauges applies over the entire measuring
range. Regardless of whether the partmeasures 10 mm or 100 mm, its actual
dimensions are always measured with thesame high quality. The high repeatability of
HEIDENHAIN length gauges is beneficial
during comparative measurements, suchas in serial production.
The HEIDENHAIN-CERTO length gauges,
in particular, exhibit high accuracy and offer
nanometer-level resolution.

Wide range of applications

HEIDENHAIN length gauges are suited formany applications. Automatic inspection
equipment, manual measuring stations or
positioning equipment—wherever lengths,
spacing, thickness, height, or linear motion
are to be measured, HEIDENHAIN length
gauges function quickly, reliably, andaccurately.

Absolute position measurement

The HEIDENHAIN-ACANTO length gauges
operate with absolute measurement over arange of 12 mm or 30 mm and with highrepeatability. Their particular advantage isthat the measured value is available
immediately after switch-on.

Expertise

The high quality of HEIDENHAIN length
gauges is no coincidence. HEIDENHAIN
has been manufacturing high-accuracy
scales for over 70 years, and for many
years it has developed measuring andtesting devices for length and angle
measurement for national standards
laboratories. This know-how makes
HEIDENHAIN an extraordinarily qualified
partner for metrology questions.

Robust design

HEIDENHAIN length gauges are built for
an industrial environment. Their long-term
consistent accuracy and high thermal
stability make them ideal for use inproduction equipment and machines.

6

Worldwide presence

HEIDENHAIN is represented in allimportant industrial countries—in most ofthem with wholly owned subsidiaries.
Sales engineers and service technicians
support the user on-site with technicalinformation and servicing in the local
language.

7

Overview of length gauges

Accuracy

Measuring range
Plunger actuation

12 mm

25 mm/30 mm

60 mm

100 mmpage

Absolute position measurement
±1 µm
±2 µm

22

HEIDENHAIN-ACANTO
Via measured object

AT 1218 EnDat

AT 3018 EnDat

PneumaticallyAT 1217 EnDat

AT 3017 EnDat

Incremental linear measurement±0.1 µm*)±0.05 µm
±0.03 µm*)±0.2 µm±0.5 µm
±1 µm

±1 µm

*)

MT 101

8

MT 60

CT 6000

24

HEIDENHAIN-CERTO
Via motor

CT 2501 » 11 µAPP

CT 6001 » 11 µAPP

Via external coupling

CT 2502 » 11 µAPP

CT 6002 » 11 µAPP

26

HEIDENHAIN-METRO
Via cable release ormeasured object

MT 1271 « TTL
MT 1281 » 1 VPP

MT 2571 « TTL
MT 2581 » 1 VPP

PneumaticallyMT 1287 » 1 VPP

MT 2587 » 1 VPP

28HEIDENHAIN-METRO
Via motor

MT 60 M » 11 µAPP

MT 101 M » 11 µAPP

Via external coupling

MT 60 K » 11 µAPP

MT 101 K » 11 µAPP

30

HEIDENHAIN-SPECTO
Via measured object

ST 1278 « TTL
ST 1288 » 1 VPP

ST 3078 « TTL
ST 3088 » 1 VPP

Pneumatically

ST 1277 « TTL
ST 1287 » 1 VPP

ST 3077 « TTL
ST 3087 » 1 VPP fter linear length-error compensationAin the evaluation electronics

CT 2500

MT 2500

MT 1200

ST 3000

ST 1200

AT 3000

AT 1200

9

Measuring principles

Measuring standard

Measurement procedure

Photoelectric scanning principle

HEIDENHAIN length gauges arecharacterized by long measuring ranges
and consistently high accuracy. The basis
for both is the photoelectrical scanningprinciple.

With the incremental measuringmethod, the graduation consists of aperiodic grating structure. The position
information is obtained by counting theindividual increments (measuring steps)
from some point of origin. Since anabsolute reference is required to ascertain
positions, the measuring standard isprovided with an additional track that bears
a reference mark. The absolute position on
the scale, established by the referencemark, is gated with exactly one signal
period.

Most HEIDENHAIN encoders operateusing the principle of photoelectricscanning. Photoelectric scanning of ameasuring standard is contact-free, and assuch, free of wear. This method detects
even very fine lines, no more than a few
micrometers wide, and generates output
signals with very small signal periods.

HEIDENHAIN length gauges use material
measuring standards consisting of absoluteor incremental graduations on substrates
of glass or glass ceramic. These measuring
standards permit large measuring ranges,
are insensitive to vibration and shock, andhave a defined thermal behavior. Changes inatmospheric pressure or relative humidity
have no influence on the accuracy of themeasuring standard—which is theprerequisite for the high long-term
stability of HEIDENHAIN length gauges.
HEIDENHAIN manufactures the precision
graduations in specially developed,
photolithographic processes.
• AURODUR: matte-etched lines on goldplated steel tape with typical graduation
period of 40 µm• METALLUR: contamination-tolerant
graduation of metal lines on gold, withtypical graduation period of 20 μm• DIADUR: extremely robust chromiumlines on glass (typical graduation periodof 20 μm) or three-dimensional chromium
structures (typical graduation period of8 μm) on glass• SUPRADUR phase grating: opticallythree dimensional, planar structure;
particularly tolerant to contamination;
typical graduation period of 8 μm andfiner• OPTODUR phase grating: optically three
dimensional, planar structure withparticularly high reflectance, typicalgraduation period of 2 μm and finer
Along with these very fine grating periods,
these processes permit a high definitionand homogeneity of the line edges.
Together with the photoelectric scanning
method, this high edge definition is aprecondition for the high quality of theoutput signals.

The reference mark must therefore be
scanned to establish an absolute referenceor to find the last selected datum.
With the absolute measuring method,
the position value is available from theencoder immediately upon switch-on andcan be called at any time by the subsequent
electronics. There is no need to move theaxes to find the reference position. The
absolute position information is read fromthe measuring standard, which is formed
from a serial absolute code structure. A
separate incremental track is interpolated
for the position value and at the sametime—depending on the interface
version—is used to generate an optional
incremental signal.

DIADUR phase grating with approx. 0.25 µm
grating height

The finer the grating period of a measuring
standard is, the greater the effect ofdiffraction on photoelectric scanning.
HEIDENHAIN linear encoders use twoscanning principles:• The imaging scanning principle forgrating periods of 20 µm and 40 µm• The interferential scanning principle
for very fine graduations with grating
periods of, for example, 8 µm.

Imaging principle
To put it simply, the imaging scanningprinciple functions by means of projectedlight signal generation: two scale gratings
with equal or similar grating periods are
moved relative to each other—the scale
and the scanning reticle. The carriermaterial of the scanning reticle is transparent,
whereas the graduation on the measuring
standard may be applied to a transparent
or reflective surface.
When parallel light passes through a
grating, light and dark surfaces areprojected at a certain distance. An index
grating is located here. When the two
graduations move in relation to each other,
the incident light is modulated: if the gaps
are aligned, light passes through. If thelines of one grating coincide with the gapsof the other, no light passes through. A
photocell array converts these variations inlight intensity into electrical signals. The
specially structured grating of the scanning
reticle filters the light to generate nearlysinusoidal output signals.
The smaller the period of the grating
structure is, the closer and more tightly
toleranced the gap must be between thescanning reticle and scale.

Interferential scanning principle
The interferential scanning principle
exploits the diffraction and interference oflight on a fine graduation to produce
signals used to measure displacement.
A step grating is used as the measuring
standard: reflective lines 0.2 µm high areapplied to a flat, reflective surface. In front ofthat is the scanning reticle—a transparent
phase grating with the same grating period
as the scale.
When a light wave passes through thescanning reticle, it is diffracted into threepartial waves of the orders –1, 0, and +1,
with approximately equal luminous intensity.
The waves are diffracted by the scale suchthat most of the luminous intensity is foundin the reflected diffraction orders +1 and –1.
These partial waves meet again at thephase grating of the scanning reticle where
they are diffracted again and interfere. This
produces essentially three waves that leave
the scanning reticle at different angles.
Photovoltaic cells convert this alternating
light intensity into electrical signals.

A relative motion of the scanning reticle tothe scale causes the diffracted wave fronts
to undergo a phase shift: When the grating
moves by one period, the wave front of thefirst order is displaced by one wavelength
in the positive direction, and the wavelengthof diffraction order –1 is displaced by one
wavelength in the negative direction. Since
the two waves interfere with each otherwhen exiting the grating, the waves are
shifted relative to each other by two
wavelengths. This results in two signal
periods from the relative motion of just one
grating period.
Interferential encoders function withgrating periods of, for example, 8 µm, 4 µm,
and finer. Their scanning signals are largely
free of harmonics and can be highlyinterpolated. These encoders are therefore
especially suited for high resolution andhigh accuracy.
The HEIDENHAIN-CERTO length gauges,
as well as the MT 1200 and MT 1500
HEIDENHAIN-METRO length gauges, use
the interferential principle.

The HEIDENHAIN-ACANTO andHEIDENHAIN-SPECTO length gauges,
as well as the MT 60 and MT 100
HEIDENHAIN-METRO length gauges,
use the imaging principle.

DIADUR graduation

5µmInterferential scanning principle (optics schematics)
C Grating periody Phase shift of the light wave when passing through the scanning reticle
 Phase shift of the light wave due to motion X of the scale

Imaging principle

LED light source
Photocells

Condenser lens

LED light
sourceCondenser lens

The master graduations are manufactured
by HEIDENHAIN on custom-built highprecision dividing engines.

Scanning reticle
Measuring standard

Scanning reticle

Photocell array

Measuring standard

10

11

Measuring accuracy

The linear measurement accuracy is mainly
determined by the following factors:• The quality of the graduation• The scanning quality• The quality of the signal processing
electronics• The eccentricity of the graduation
relative to the bearing• The guideway error of the scale relative
to the scanning unit
• The orthogonality of the length gauge
relative to the bearing surface.
These factors can be divided into encoderspecific errors and application-specificfactors. For assessment of the attainable
overall accuracy, all of these individual
factors must be taken into account.

Error specific to the measuring
device
The error that is specific to the measuring
device is stated in the specifications as thesystem accuracy.
The extreme values of the total error Fof a position are, on average, within thesystem accuracy ±a along the entire
measuring range. They are measured
during final inspection and documented
in the calibration chart.
The system accuracy includes thefollowing:• The homogeneity and period definitionof the graduation• The alignment of the graduation• The error of the bearing• The position error within one signal
period.
The Interpolation error within one
signal period
The interpolation error within one signal
period has an effect even during very small
movements and repeated measurements.
It is therefore considered separately.
The interpolation error within one signal
period ±u results from the scanning quality
and, for encoders with integrated pulseshaping or counter electronics, the qualityof the signal-processing electronics.
For encoders with sinusoidal output
signals, however, the error from the signal
processing electronics is dictated by thesubsequent electronics.

Position error 
Signal level Position error 

Position 

These sources of error must be consideredwhen specifying the interpolation error
within one signal period.
The interpolation error within one signal
period ±u is specified as a percentage ofthe signal period. For length gauges, thisvalue is typically better than ±1% of thesignal period. You will find the specified
values in the Specifications.
Short-range accuracy
The short-range accuracy describes theamount of error that occurs within adistance of ±100 µm from a measuring
point and includes electronic andmechanical influences of the gauge on themeasurement. The values for short-range
accuracy typically lie below the specified
values.

Application-dependent error
Other factors besides the system accuracy
also influence the attainable total accuracy ofmeasurement. These include in particular
the ambient temperature and temperaturefluctuations during measurement as well
as a stable, orthogonal measuring setup.
All components included in the measuringloop, such as the holder for the measured
object, the gauge stand with holder, and thelength gauge itself, influence the result of
measurement. Expansion or deformationof the measuring setup through mechanicalor thermal influences adds directly to theerror.

Orthogonal mounting
The length gauge is to be mounted so thatits plunger is exactly orthogonal to themeasured object or the surface on which it
rests. Deviations result in measuring error.
The accessory HEIDENHAIN gauge stands
with holders for an 8 mm clamping shankensure orthogonal mounting. Length gauges
that provide planar mounting surfaces
must be set parallel to the mounting surface(Y) and perpendicularly to the measuring
plate. A quick and reliable adjustment ispossible with the aid of a gauge block or aparallel block. The perpendicularity to themeasuring table (X) is already ensured by
the gauge stand.

Mechanical design
A stable measuring assembly must be
ensured. Long lateral elements within themeasuring loop are to be avoided. HEIDEN­
HAIN offers a stable gauge stand as anaccessory. The force resulting from themeasurement must not cause any meas­
urable deformation of the measuring loop.

Thermal characteristics
Temperature variations during measurement
cause changes in length or deformation of
the measuring setup. After a change intemperature of 5 K, a steel bar of 200 mm
length expands by 10 µm.
Length changes resulting from a uniform
deviation from the reference temperature
can largely be compensated by resetting
the datum on the measuring plate or amaster; only the expansion of the scale
and measured object go into the result of
measurement.
Temperature changes during measurement
cannot be ascertained mathematically. For
critical components, HEIDENHAIN
therefore uses special materials with low
coefficients of expansion, such as arefound in the HEIDENHAIN-CERTO gauge
stand. This makes it possible to guarantee
the high accuracy of HEIDENHAIN-CERTO
even at ambient temperatures of 19 °C to
21 °C and variations of ±0.1 K during
measurement.
In order to measure with complete
accuracy, the length gauge should beswitched on approximately 15 minutes
before the first measurement.

Length gauges from HEIDENHAIN operatewith small gauging force and have very
little influence on the measuring setup.

The measuring loop: All components involvedin the measuring assembly, including the lengthgauge

Accuracy of the interpolation

Position error a along the measuring length ML

Interpolation
error within
one signal
periodThe following factors influence theoutcome:• The fineness of the signal period• The homogeneity and period definitionof the graduation• The quality of the scanning filter
structures• The characteristics of the sensors• The stability and dynamic performanceof the analog signal processing

Orthogonal mounting

Thermal length change: Expansion of themeasuring loop components as a result of heat

Interpolation
error

Signal period
360° elec.

Position

1213

Calibration chart

Repeatability

All HEIDENHAIN length gauges areinspected before shipping for accuracy andproper function.

Whereas the system accuracy applies overthe entire measuring range, for some
applications the repeatability is the decisive
factor. It plays an important role in repeatedmeasurements.

They are calibrated for accuracy during
retraction and extension of the plunger.
For the HEIDENHAIN-CERTO, the numberof measuring positions is selected toascertain very exactly not only the longrange error, but also the position error
within one signal period.

Repeatability is defined in the standards
DIN 32876 and DKD‑R 4‑3, and describes alength gauge’s capability to supply very
similar measured values for identicalmeasurands and conditions.

The Quality Inspection Certificate
confirms the specified system accuracy ofeach length gauge. The calibration
standards ensure the traceability—asrequired by EN ISO 9001—to recognizednational or international standards.
For the HEIDENHAIN-METRO andHEIDENHAIN-CERTO series, a calibration
chart documents the position error overthe measuring range. It also shows themeasuring step and the measuring
uncertainty of the calibration measurement.

HEIDENHAIN ascertains the repeatability of
the length gauges with five measurements
near the lower plunger stop. The plunger iscompletely extended and retracted at
medium speed. Since the length gauge wasalready in operation for at least 10 minutes
before this, it is already in a stable thermal
state.

SeriesRepeatability< x + 2s

AT 1200

0.4 µm

AT 3000

0.8 µmCT 2500

0.02 µm

The repeatability of the length gauges isusually better than the values listed in thetable. The characteristic statistical distribution
is shown in the diagram, using the ST 1200
as an example.

CT 6000

0.03 µm

MT 1010.04 µm

MT 1200

0.03 µm

Repeatability depends on the• combinations of materials used in thecomponents,• installed electronics,• optomechanics used, and the• bearing of the plunger.

MT 2500

0.09 µm

MT 600.06 µm

ST 1200

0.25 µm

ST 3000

0.7 µmFor the HEIDENHAIN-METRO the calibration
chart shows the mean value of one forward
and one backward measuring stroke.

Frequency 

The HEIDENHAIN-CERTO calibration chartshows the envelope curve of the measured
error. The HEIDENHAIN-CERTO length
gauges are supplied with two calibration
charts, each for different operatingorientations.

0.25 µm

1
Operating orientation for calibration chart 1
Example2
4
3

Operating orientation for calibration chart 2

14

Temperature range
The length gauges are inspected at areference temperature of 20 °C. The
system accuracy given in the calibration
chart applies at this temperature.
The operating temperature range
indicates the ambient temperature limits
between which the length gauges willfunction properly.
The storage temperature range of –20 °C
to 60 °C applies for the device in its
packaging.

0
0

–2σ

–σ

x

σ

2σ
Repeatability 

ST 1200: Statistical distribution of the repeatability

15

Mounting

Setup

Abbe principle
HEIDENHAIN length gauges enable you towork according to the Abbe measuring
principle: the measured object and scalemust be in alignment to avoid additional
measuring error.

CT 6000
MT 60
MT 101

Fastening
The CT 6000, MT 60, and MT 101 length
gauges are fastened by two screws onto aplane surface. This ensures a mechanicallystable installation of even these large
length gauges. Special holders are available
for fastening the MT 60 and MT 101 to theMS 100 gauge stand for the HEIDENHAINMETRO (see Accessories).

The plungers of the HEIDENHAIN length
gauges are locked against rotation. Their
optimally round form stays unchanged
while stability and thermoconductivity
remain unimpaired. They are provided withan M2.5 thread to hold measuring contacts(see Accessories)

– 

The CT 2500 is mounted by its standard
clamping shank with 16h8 diameter. A
holder is available for fastening theHEIDENHAIN-CERTO to the gauge stand(see Accessories).
The AT, ST, MT 1200, and MT 2500 length
gauges feature a standard clamping shankwith 8h6 diameter. These HEIDENHAIN
length gauges can therefore easily be usedwith existing measuring fixtures andstands.

HEIDENHAIN length gauges function
according to the Abbe measuring
principle, i.e. the measuring standard andthe plunger are exactly aligned. Allcomponents comprising the measuringloop, such as the measuring standard,plunger, holder, and scanning head aredesigned in terms of their mechanical andthermal stability for the highest possible
accuracy of the length gauge.

CT 2500  Thermal characteristics
HEIDENHAIN length gauges have a defined
thermal behavior. Since temperature
variations during measurement can resultin changes in the measuring loop, HEIDEN­
HAIN uses special materials with low
coefficients of expansion Þtherm for thecomponents of the measuring loop, forexample in the CERTO length gauges.
The scale is manufactured of Zerodur(Þtherm  0 K–1), and the plunger and holder
are of Invar (Þtherm  1 x 10–6 K–1). This
makes it possible to guarantee its highmeasuring accuracy over a relatively large
temperature range.

Shock and vibration of any kind, however,are to be avoided during measurement so
as not to impair the high accuracy of themeasurement. The maximum values givenin the specifications for shock and vibration
apply to the effect of external accelerationon the length gauge. They describe only
the mechanical stability of the length
gauge, and imply no guarantee of functionor accuracy.
In the length gauge itself, unchecked
extension of the spring-driven or noncoupled moving plunger can cause highacceleration onto the measured object ormeasuring plate surface. For the MT 1200
and MT 2500 series length gauges, use
the cable release whenever possible (seeAccessories). The cable release features
adjustable pneumatic damping to limit theextension velocity to an uncritical value.

The plungers of the HEIDENHAIN-ACANTO
and HEIDENHAIN-SPECTO ST 1200 length
gauges are protected by a rubber bellows.
The bellows is characterized by highresistance to chemical and thermal
influences and have a relatively low stiffness.
Its influence on the gauge’s mechanicalbehavior and the measuring force istherefore low.



HEIDENHAIN offers the choice of a special
clamping sleeve or a clamping bush with
one screw each. These accessories make iteasier to fasten the length gauge without
overloading the 8h6 clamping shank or
damaging the ball-bush guide. The clamping
bush also enables a wide tolerance field forthe tightening torque and improves fastening.
Clamping sleeve:
ID 386811-01
Clamping bush:ID 1177968-02

Secured with clamping sleeve
Design of CT 6000
MT 60

Design of ST 1200

Connecting cable
Measuring standard(scale)Scanning unit with lightsource and photovoltaic cells

Holder
Secured with clamping bushOperating orientation for
HEIDENHAIN-CERTO
The HEIDENHAIN-CERTO can be operated
at any attitude. However, the mounting
position with horizontal length gauge andupward facing mounting surface should be
avoided because in such a case no
guarantee can be made for accuracy.

Acceleration
Length gauges from HEIDENHAIN feature
a sturdy design. Even high vibration andshock loads have no negative influence on
accuracy.

Scanning unit with lightsource, photocells andscanning electronics
Measuring standard
Ball-bush guideBall-bush guide
PlungerRubber bellows
Measuring contact

Plunger

Measuring contact1617

Gauging force and plunger actuation

Plunger guideway
HEIDENHAIN length gauges are available
with various plunger guides.
The plungers of the HEIDENHAINACANTO length gauges work with sliding
guides. The sliding guides have thefollowing properties:• Sturdiness thanks to few moving parts• Impervious to shock and vibration• High plunger speeds and long service life
thanks to high-quality ceramic bearings• Less sensitivity to improper clamping

The HEIDENHAIN-METRO, HEIDENHAINCERTO, and HEIDENHAIN-SPECTO length
gauges are equipped with a ball-bushguide. The following are some of thebasic properties of ball-bush guides in
HEIDENHAIN length gauges:• Low friction, which makes versions oflength gauges with reduced gauging
force possible• Safe plunger extension and retraction
even with high radial force• High precision of the measuring loop
thanks to a guide that is free of play (thebearing and plunger are specially fitted
during manufacture)

Expendable parts
HEIDENHAIN length gauges containcomponents that are subject to wear,
depending on the application andmanipulation. These include in particular
the following parts:• Guideway (tested for at least 60 million
strokes*)• Cable link for CT, MT 60, and MT 101(tested for at least 1 million strokes*)• Scraper rings• Rubber bellows for AT and ST 1200
* With CT, MT 60M, and MT 101M onlywith actuation by switch box
Note
DIADUR is a registered trademark of
DR. JOHANNES HEIDENHAIN GmbH,
Traunreut, Germany. Zerodur is a registeredtrademark of Schott Glaswerke in Mainz,
Germany.

Gauging force
Gauging force is the force that the plunger
exercises on the measured object. If thegauging force is too high, then the measuringcontact or measured object may deform in
response. If the gauging force is too low,then a layer of dust or contamination may
prevent the plunger from fully contacting
the measured object. The gauging force
depends on the type of plunger actuation.
Spring-based plunger actuation
For the AT 1218, AT 3018, MT 12x1,
MT 25x1, ST 12x8, and ST 30x8, a built-in
spring extends the plunger to the measuring
position and produces the gauging force.
The plunger is extended when at rest. The
gauging force depends on the following
criteria:• The operating orientation• The plunger position (the force changes
over the course of the measuring range)• The direction of measurement (whether
extension or retraction of the plunger isused)

The gauging forces can be divided into thefollowing classes:• Reduced MR: approx. half the gauging
force of the standard variant• Low MW: gauging force at the beginningof the measuring range, approx. 0.01 N• Springless MG: constant gauging force
over the entire measuring range
So as not to influence the gauging force,
the ST 1288 MR and ST 1288 MG variants
are provided without a bellows.
Plunger actuation via measured object
The complete length gauge is moved by
the measuring device toward the measured
object, or vice versa. The measurement isusually performed via plunger retraction.

Built-in, adjustable pneumatic damping
reduces the plunger extension speed so as
to prevent rebound (e.g., on very hardmaterials). This prevents measuring error
due to bouncing.

The graphs show the gauging force acrossthe measuring range during horizontal
retraction and extension of the plunger.

Ball-bush guide

The MT 1281 and ST 1288 length gauges
are available with various gauging forces.
Delicate materials can therefore bemeasured without deformation.

Special variants

12 mm measuring range
MT 12x1 extending
MT 12x1 retracting
ST 12x8 extending
ST 12x8 retracting
AT 1218 extending
AT 1218 retracting

extendingretracting
extendingretracting

0.35

Gauging force in N 

Gauging force in N 

MT 1281 MR
MT 1281 MR
ST 1288 MR
ST 1288 MR

0.30
0.25
0.20

25 mm/30 mm measuring range

Gauging force in N 

Sliding guide

Plunger actuation via a cable release(MT 12x1, MT 25x1)
In this method, the plunger is manuallyraised and lowered onto the measured
object by means of a cable release. Thismeasurement is performed with plunger
extension.

MT 25x1 extending
MT 25x1 retracting
ST 30x8 extending
ST 30x8 retracting
AT 3018 extending
AT 3018 retracting

2.0
1.8
1.6
1.4
1.2
1.0

0.15

0.8
0.10

0.6

0.05

0.4

0.00

0.2

Distance in mm 

18

Distance in mm 

0

5

10

15

20

25

30

Distance in mm 

19

Pneumatic plunger actuation
The pneumatically actuated plungers of the
AT 1217, AT 3017, MT 1287, MT 2587,
ST 12x7, and ST 30x7 length gauges areextended by the application of compressed
air. When the air connection is ventilated,
the integral spring retracts the plunger. to aprotected resting position within the
housing.

The working pressure defines the pressure
range of the first complete plunger extension
up to the maximum specified range.

The gauging force can be adjusted to themeasuring task through the level of airpressure. At constant pressure, it depends
on the operating orientation and theplunger position.
The diagrams show the respective gauging
force for a horizontal operating orientation
depending on the working pressure appliedwith the plunger fully extended and fully
retracted. These are approximate values
that are subject to changes due totolerances and depend on seal wear.

12 mm measuring range(pneumatically actuated)

HEIDENHAIN offers the DA 400
compressed air unit for purifying
compressed air. The minimum flow rate is
10 l/min.
For more information, ask for our DA 400
Product Information Sheet.

25 mm/30 mm measuring range(pneumatically actuated)

The diagrams apply for the horizontal
operating orientation, except for special
variants. The following compensation
values are to be taken into account forother operating orientations.

MT 2587 retracted
MT 2587 extended
ST 30x7 retracted
ST 30x7 extended
AT 3017 retracted
AT 3017 extended

2.4

Gauging force in N 

Gauging force in N 

MT 12x7 retracted
MT 12x7 extended
ST 12x7 retracted
ST 12x7 extended
AT 1217 retracted
AT 1217 extended

Model
2.0

1.6

0.0
0.4

Pressure in bar 

Downward–0.12 N
–0.18 N

+0.12 N
+0.18 NMT 12xx–0.13 NMT 1281MR–
MT 25x1–0.17 NMT 2587–0.19 N

+0.13 N
+0.13 N
+0.17 N
+0.19 N

–0.07 N
–0.08 N
–0.11 N

+0.07 N
+0.08 N
+0.11 N

1.2

0.4

0.8

1.2

1.6

2.0

2.4

2.8

Pressure in bar 

ST 12x7
ST 12x8
ST 30xx

Motorized plunger actuation
The CT 2501, CT 6001, MT 60 M, andMT 101 M length gauges feature an integral
motor that moves the plunger. It is operated
through the switch box either by push button
or over the connection for external actuation.
The plungers of the CT 2501, CT 6001, andMT 60 M length gauges must not be moved
by hand if the switch box is connected.
The gauging force of the CT 2501, CT 6001,
and MT 60 M motorized length gauges isadjustable in three stages through theswitch box. The force remains constantover the measuring range but depends on
the operating orientation.
Regardless of the operating orientation—
whether it measures vertically downward(with the SG 101V switch box) or horizontally(with the SG 101 H switch box)—theMT 101 M exercises a constant gauging
force.
CT 2501
CT 6001

MT 60 M

MT 101 M

Gauging force

Via motor

Via motor

Via motor

Vertically downward

0.85 N/1 N/1.45 N

1 N/1.25 N/1.75 N

0.7 N with SG 101V

Vertically upward–/–/0.55 N–/–/0.85 N–

Horizontal–/0.55 N/1 N–/0.8 N/1.3 N

0.7 N with SG 101 H

External plunger actuation via coupling
For the CT 2502, CT 6002, MT 60 K,
MT 101 K, and special versions (without
spring) of the MT 1200, MT 2500, andST 1288, the plunger is freely movable.
For position measurement, the plunger isconnected by a coupling with a moving
machine element. The force needed tomove the plunger is specified as therequired moving force. It depends on theoperating orientation.

Operating orientation
verticalUpwardAT 121x
AT 301x

0.8

20

Note
The compressed air introduced directly into
the length gauges must be properly
conditioned and must comply with thefollowing quality classes as per ISO 8573-1(1995 edition):• Solid contaminant: Class 1(max. particle size 0.1 µm and max.
particle density 0.1 mg/m3 at 1 · 105 Pa)• Total oil content: Class 1(max. oil concentration 0.01 mg/m3
at 1 · 105 Pa)• Max. pressure dew point: Class 4
but with reference conditions of +3 °C at
2 · 105 Pa

CT 2502
CT 6002

MT 60 KMT 101 K

MT 1271 « TTL
MT 1281 » 1 VPP

MT 2571 « TTL
MT 2581 » 1 VPP

ST 1288

Gauging force

Moving force1)

Moving force1)

Moving force1)

–

–

–

Vertically downward

0.45 N

0.4 N

1.7 N

0.13 N

0.17 N

0.2 N

Vertically upward

0.55 N

0.55 N

2N

–

–

–

Horizontal

0.15 N

0.15 N

0.4 N

–

–

–

1)

Force required to move the plunger or the force of its weight21

HEIDENHAIN-ACANTO
Absolute length gauges with EnDat interface• Online diagnostics• Protection rating of up to IP67
• Serial data transmission with CRC

AT 1200

AT 3000

Mechanical data

AT 1218

Plunger actuation
Position of plunger at rest

Via measured object
Extended

Measuring standard

DIADUR grating on glass; grating period: 188.4 µm

System accuracy±1 µm

Position error per signal period

 ±0.7 µm

Measuring range

12 mm

Working pressure–

Mech. permissible traversing speed

 80 m/min

Radial force

 0.5 N (mechanically permissible)

Fastening

Clamping shank ¬ 8h6

Operating orientation

Any

Vibration 55 Hz to 2000 Hz
Shock 11 ms

 100 m/s (EN 60068-2-6)
 500 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 40 °C; reference temperature: 20 °C

Protection EN 60529

IP67

Mass without cable

80 g

1)

Dimension changes under max. pressure (1.8 bar)

ML = Measuring length = Clamping area
 = Air connection for 2 mm tube

22

AT 3018

AT 1217

AT 3017

Pneumatic
Retracted

±2 µm

±1 µm

±2 µm

30 mm

12 mm

30 mm

0.7 bar to 1.8 bar

1.1 bar to 1.8 bar

 80 m/min

 120 m/min

 120 m/min

2

1)

1)

IP64
IP67 upon request

IP64

100 g

80 g

100 g

368 nm23 nm

368 nm

IP67 with sealing air

Electrical data

EnDat

Interface

EnDat 2.2

Ordering designation

EnDat 22

Measuring step

23 nm

Calculation time tcal
Clock frequency

 5 µs 8 MHz

Electrical connection

8-pin M12 flange socket (male)

Cable length 100 m with HEIDENHAIN cable

Supply voltage

DC 3.6 V to 14 V

Power consumption (max.)

3.6 V:  550 mW
14 V:  650 mW

Current consumption (typical)

5 V: 80 mA (without load)

23

HEIDENHAIN-CERTO

Incremental length gauges with ±0.1 μm/±0.051) μm*/±0.03 μm1) accuracy• For very high accuracy• Low thermal expansion through thermally invariant materials• High-precision ball bearing guideCT 2500

Mechanical data

CT 2501

CT 6001

CT 2502

CT 6002

Plunger actuation

Via motor

Measuring standard

DIADUR phase grating on Zerodur glass ceramic; grating period: 4 µm

System accuracy
at 19 °C to 21 °C±0.1 µm,
1)±0.03 µm

Position error per signal period

 ±0.02 µm

Short-range accuracy typically

0.03 µm

Reference markOne, approx. 1.7 mm below upper stop

Measuring range

25 mm

Radial force

 0.5 N (mechanically permissible)

Fastening

Clamping shank(¬ 16h8)Operating orientation

Any (for preferred operating orientation, see Mounting)Vibration 55 Hz to 2000 Hz
Shock 11 ms

2
 100 m/s (EN 60068-2-6)
 1000 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 40 °C; reference temperature: 20 °C

Protection EN 60529

IP50

Mass without cable

520 g

700 g

480 g

640 g

Electrical data

CT 2501

CT 6001

CT 2502

CT 6002

Interface» 11 µAPP

Signal period

2 µm

Measuring velocity

 24 m/min (depending on the subsequent electronics)
 12 m/min with the ND 28x digital readout

Electrical connection*• Cable 1.5 m with 15-pin D-sub connector (male)• Cable 1.5 m with 9-pin M23 connector (male)Interface electronics integrated in connector

Cable length 30 mSupply voltage

DC 5 V ±0.25 V/< 170 mA

DC 5 V ±0.25 V/< 120 mA

Required accessories*

For CT 2501

For CT 6001

Switch box

SG 25 M

SG 60 MVia coupling with moving machine part±0.1 μm,±0.05 μm1)

60 mmPlane surface±0.1 µm,±0.03 µm1)

±0.1 μm,±0.05 μm1)

25 mm

60 mm

Clamping shank(¬ 16h8)

Plane surface

CT 6000Ⓡ = Reference markposition24* Please select when ordering
After linear length-error compensation in the evaluation electronics
2)
Force required to move the plunger or the force of its weight
1)

25

HEIDENHAIN-METRO
Incremental length gauges with ±0.2 µm accuracy• High repeatability• Various gauging force variants• Various possibilities for plunger actuation

MT 1200

MT 12x1

MT 1287

L1

18.5

22.0

L2

10.1

6.2

L3

8.1

4.2

MT 2500

MT 25x1

MT 2587

L1

37.0

41.0

L2

10.1

6.2

L3

8.1

4.2

MT 1287
MT 2587

MT 2571 « TTL MT 1287 » 1 VPP
MT 2581 » 1 VPP

MT 1271 « TTL
MT 1281 » 1 VPP

Plunger actuation
Position of plunger at rest

Via cable or measured object
Extended

Measuring standard

DIADUR phase grating on Zerodur glass ceramic; grating period: 4 µm

System accuracy±0.2 µm

Position error per signal period

 ±0.02 µm

Short-range accuracy typically

0.03 µm

Reference mark≈ 1.7 mm below upper stop

Measuring range

12 mm

Working pressure–

Radial force

 0.8 N (mechanically permissible)

Fastening

Clamping shank ¬ 8h6

Operating orientation

Any; for version without spring and with low gauging force: vertically downward

Vibration 55 Hz to 2000 Hz
Shock 11 ms

2
 100 m/s (EN 60068-2-6)
 1000 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 40 °C; reference temperature: 20 °C

Protection EN 60529

IP50

Mass without cable

100 g

Electrical data

MT 1271
MT 2571

MT 128xMT 258xInterface« TTL» 1 VPP

Integrated interpolation*

5-fold10-fold–

Signal period

0.4 µm

0.2 µm2 µm

Mech. permissible traversing speed 30 m/min

Edge separation a at scanning1)
frequency*/traversing speed		
200 kHz  24 m/min		
100 kHz  12 m/min
		  50 kHz  6 m/min
		  25 kHz  3 m/min

 0.23 µs
 0.48 µs
 0.98 µs––
 0.23 µs
 0.48 µs
 0.98 µs–

0.04 µm

25 mm

26Pneumatic
Retracted

0.03 µm0.04 µm

12 mm

25 mm

0.9 bar to 1.4 bar

IP67 (with sealing air)
180 gElectrical connection*
Cable 1.5 m with 15-pin D-sub connector(interface electronics integrated in connector) (male)Ⓡ = Reference mark positionⓈ = Beginning of measuring lengthÀ = Clamping area
Á = Air connection for 2 mm tube

MT 2587 » 1 VPP

Mechanical data

Cable length 30 m with HEIDENHAIN cable

Voltage supply

DC 5 V ±0.5 V/< 160 mA (without load)* Please select when ordering    1) At the corresponding cutoff or scanning frequency

110 g

190 g

Cable 1.5 m with• 15-pin D-sub connector (male)• 12-pin M23 connector (male)DC 5 V ±0.25 V/< 130 mA

27

HEIDENHAIN-METRO
Incremental length gauges with ±0.5 µm/±1 µm accuracy• Large measuring ranges• Plunger actuation by motor or coupling• Ball-bush guided plunger

MT 60 M

MT 101 M

28

MT 60

Mechanical data

MT 60 M

MT 101 M

MT 60 K

Plunger actuation

Via motor

Measuring standard

DIADUR grating on silica glass; grating period: 10 µm

System accuracy±0.5 µm

Position error per signal period

 ±0.1 µm

Reference markMT 101 K

Via coupling with moving machine part

±1 µm

±0.5 µm±1 µm≈ 1.7 mm from top≈ 10 mm from top≈ 1.7 mm from top≈ 10 mm from top

Measuring range

60 mm

100 mm

60 mm

100 mmRadial force mechanically permissible

 0.5 N

2N

 0.5 N

2N

Fastening

Plane surface

Operating orientation

Any

Vertically downward
with SG 101V
Horizontal with
SG 101 H

Any

Vibration 55 Hz to 2000 Hz
Shock 11 ms

2
 100 m/s (EN 60068-2-6)
 1000 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 40 °C; reference temperature: 20 °C

Protection EN 60529

IP50

Mass without cable

700 g

1400 g600 g1200 gElectrical data

MT 60 M

MT 101 M

MT 60 KMT 101 K

Interface» 11 µAPP

Signal period

10 µm

Measuring velocity

 18 m/min

 60 m/min

 18 m/min

 60 m/min

Electrical connection*

Cable, 1.5 m, with 15-pin D-sub connector (male) or with 9-pin M23 connector (male)

Cable length 30 m with HEIDENHAIN cable

Supply voltage

DC 5 V ±0.25 V

Current consumption< 120 mA

Required accessories*

For MT 60 M

For MT 101 M

Switch box

SG 60 M

Vertical orientation: SG 101 V
Horizontal orientation: SG 101 H

Power adapter–

Required (see Accessories)

MT 101Ⓡ = Reference mark position< 70 mA* Please select when ordering

29

HEIDENHAIN-SPECTO
Incremental length gauges with ±1 µm accuracy• Very compact dimensions• Protection rating of up to IP67
• Especially durable ball-bush guide

ST 1200

ST 3000

ST 12x7
ST 30x7

ST 3078 « TTL
ST 3088 » 1 VPP

ST 1277 « TTL
ST 1287 » 1 VPP

Mechanical data

ST 1278 « TTL
ST 1288 » 1 VPP

Plunger actuation
Position of plunger at rest

Via measured object
Extended

Measuring standard

DIADUR grating on glass; grating period: 20 µm

System accuracy±1 µm

Position error per signal period

 ±0.2 µm

Short-range accuracy typically

0.3 µmReference mark≈ 5 mm below upper stop

Measuring range

12 mm

Working pressure–

Radial force

 0.8 N (mechanically permissible)

Fastening

Clamping shank ¬ 8h6

Operating orientation

Any

Vibration 55 Hz to 2000 Hz
Shock 11 ms

2
 100 m/s (EN 60068-2-6)
 1000 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 40 °C; reference temperature: 20 °C

Protection EN 60529

IP67/IP64

IP64

Mass without cable

40 g

50 g

Electrical data

ST 127x
ST 307xST 128xST 308xInterface« TTL» 1 VPP

Integrated interpolation*

5-fold10-fold–

Signal period

4 µm

2 µm

20 µm

Edge separation a at scanning2)
frequency*/traverse speed		
100 kHz  72 m/min1)
		  50 kHz  60 m/min
		  25 kHz  30 m/min

 0.48 µs
 0.98 µs
 1.98 µs

 0.23 µs
 0.48 µs
 0.98 µs–

ST 3077 « TTL
ST 3087 » 1 VPP

Pneumatic
Retracted

30 mm

12 mm

30 mm

0.8 bar to 2.5 bar

40 g

50 g





 – 















Ⓡ = Reference mark positionⓈ = Beginning of measuring length = Clamping area
 = Air connection for 2 mm tube

30



Electrical connection*

Cable 1.5 m with 15-pin D-sub connector(male, integrated interface electronics)

Cable outlet*

Axial or radial

Cable length 30 m with HEIDENHAIN cable

Supply voltage

DC 5 V ±0.5 V

Current consumption< 100 mA (without load)* Please select when ordering

1)

Mechanically limited

Cable 1.5 m with• 15-pin D-sub connector (male)• 12-pin M23 connector (male)< 55 mA
2)

At a corresponding cutoff or scanning frequency

31

Length gauges with low measuring forces
Incremental length gauges• Ball-bush guided plunger• Same specifications as for standard products

MT 1200

MT 12x1

MT 1287

L1

18.5

22.0

L2

10.1

6.2

L3

8.1

4.2

Mechanical data

MT 1281

ST 1288

Plunger actuation

Via cable or measured object

Via measured object

Measuring standard

DIADUR phase grating on Zerodur glass
ceramic; grating period: 4 µm

DIADUR grating on glass;grating period: 20 µm

System accuracy±0.2 µm±1 µm

Short-range accuracy typically

0.03 µm

0.3 µmMeasuring range

12 mm

Fastening

Clamping shank ¬ 8h6

Protection EN 60529

IP50Interface» 1 VPP

Signal period

2 µm

IP50

20 µm

1.20

Horizontal operatingorientation

1.10

ST 1288 extending

1.00

ST 1288 retracting

Gauging force in N 

0.90

ST 12

The diagram applies for the horizontal
operating orientation, except for
MT 1281 MW. For compensation values forother orientations, see the table on p. 20.

MT 1281 extending

0.80

MT 1281 retracting

0.70

ST 1288 MR extending
0.60

ST 1288 MR retracting
0.50

MT 1281 MR extending

0.40

MT 1281 MR retracting
Vertical downward
orientation

0.30
0.20

MT 1281 MW extending

0.10
0.00

MT 1281 MW retracting
0

2

4

6

8

10

12

Distance in mm 

MT 1281

ST 1288Ⓡ = Reference mark positionⓈ = Beginning of measuring length = Clamping area

32

1)
2)

VersionGauging force Operating orientation

Default

0.75 NAny desired operating orientationMR

0.25 N1)

Vertically downward and horizontal

MW

0 N1)

Vertically downwardMG

0.13 N2)

Vertically downward

Default

0.65 N1)

Any desired operating orientation

MR

0.4 N1)

Any desired operating orientation

MG

0.2 N2)

Vertically downward

With nearly fully extended plunger
Over the entire measuring range

1)33

Accessories
Measuring contacts

Switch boxes, coupling

Ball-type contact

Domed contact

Steel			ID 202504-01
Carbide		
ID 202504-02
Ruby			ID 202504-03

Carbide		

Flat contact
ID 229232-01

Steel			ID 270922-01
Carbide		
ID 202506-01

Switch boxes for CT 2501, CT 6001,
MT 60 M, MT 101 M
Switch boxes are required for length
gauges with motorized plunger actuation.
The plunger is controlled through two pushbuttons or by external signal. The SG 25 M
and SG 60 M switch boxes can adjust thegauging force in three stages.
SG 25 M
ID 317436-01
SG 60 M
ID 317436-02
SG 101V1)
For the MT 101 M in vertical operation
ID 361140-01
SG 101 H1)
For the MT 101 M in horizontal operation
ID 361140-02

Pin-type contact

Knife-edge contact

Steel			ID 202505-01

Steel			ID 202503-01

Connector (female), 3-pin
For external operation of the switch box
ID 340646-05
1)

Separate power adapter required

41Power adapter for SG 101 V/H
An adapter connected to the switch box
powers the MT 101 M.
81

Voltage range: AC 100 V to 240 V
Exchangeable plug adapter(European and U.S. connectors included
in delivery)

Roller contact, steel
For a low-friction contact with moving surfaces

Adjustable contact, carbide
For exact parallel alignment to the measuring plate surface

Crowned		
Cylindrical		Flat			ID 202507-01
Knife-edged		ID 202508-01

ID 202502-03
ID 202502-04

31.5

ID 312426-13

58

Coupling
For connecting the plunger of the length
gauge (specifically for the MT 60 K, MT 101 K,
CT 2502, and CT 6002) to a moving
machine element
ID 206310-01

34

35

Accessories for HEIDENHAIN-CERTO
Gauge standCeramic suction plate, diaphragm pump

CS 200 gauge standFor length gauges
CT 2501*				CT 6001

Ceramic suction plate
Wear-resistant working surface with highsurface quality specifically for inspecting
gauge blocks

ID 221310-01

ID 223100-01

Overall height		
350 mmMeasuring table¬ 250 mm
Column		 ¬ 58 mm
Mass			15 kg* With special holder

The gauge block (class 1 or 2)—or any
other object with a plane surface—isdrawn by suction onto the top of theceramic plate. The ceramic plate is likewisedrawn to the granite base and held in placethrough negative pressure.

The flatness of the CS 200 is determinedwith the aid of a Fizeau interferometer.

Parts for connecting the ceramic suction
plate with the diaphragm pump are among
the items supplied:
Pressure tubing: 3 m
T-joint
Connecting piece
Diaphragm pump
Source of suction for drawing the measured
object and ceramic suction plate
Power consumption 20 W
Mass			2.3 kg
Line voltage		AC 230 V / 50 Hz
ID 754220-01
No chips or flaws

Holder for CS 200
For the CT 2501 with ¬ 16 mm clampingshankLine voltage		ID 754220-02

AC 115 V / 60 Hz

ID 324391-01

36

37

Accessories for HEIDENHAIN-ACANTO, HEIDENHAIN-METRO, andHEIDENHAIN-SPECTO
Cable release and gauge stands
Cable release
For manual plunger actuation on the
MT 1200 and MT 2500. Built-in pneumatic
damping reduces the plunger extension
speed to prevent bouncing (e.g., on very
hard materials).

MS 45 gauge standFor length gauges
ATST
MT 1200
MT 2500
ID 202162-02

ID 257790-01

Overall height		
Measuring table
ColumnMass			MS 100 gauge standFor length gauges
ATST
MT 1200
MT 2500
MT 60 M1)
MT 101 M1)

MS 200 gauge standFor length gauges
AT1)
ST1)
MT 12001)
MT 25001)
MT 60 M
MT 101 M
ID 244154-01
Total height		
Base			ColumnMass			1)

196.5 mm
¬ 49 mm¬ 22 mm
2.2 kg

ID 202164-02

346 mm¬ 250 mm
¬ 58 mm
18 kg

Overall height		
Measuring table
ColumnMass			

With special holder

1)

385 mm
98 mm x 115 mm¬ 50 mm
18 kg

With special holder

Holder for the MS 200
For mounting the length gauge
with a clamping shaft (¬ 8 mm),including the AT, ST, MT 1200,
and MT 2500
ID 324391-02

Clamping sleeve and clamping bush
For all length gauges with a ¬ 8 mmclamping shaft, including the AT, ST,
MT 1200, and MT 2500, for secureattachment of the length gauge without
overburdening the 8h6 clamping shank:

Holder for MS 100
For mounting the MT 60 M
ID 207479-01
For mounting the MT 101 M
ID 206260-01

Clamping sleeve with screw
ID 386811-01 (qty. 1)
ID 386811-02 (qty. 10)
Clamping bush with screw
ID 1177968-02
Additional protection from damage to theball guide, as well as a wide tolerance
range for the tightening torque38¬ 14F8Clamping bush with screw(ID 1177968-02)39

Signal converters

The signal converters from HEIDENHAIN
adapt the encoder signals to the interfaceof the subsequent electronics. They areused when the subsequent electronics
cannot directly process the output signals
from HEIDENHAIN encoders or when
additional interpolation of the signals isnecessary.

Input signals of the interface electronics
HEIDENHAIN signal converters can beconnected to encoders with 1 VPP sinusoidal
signals (voltage signals) or 11 µAPP sinusoidal
signals (current signals). Encoders with
the EnDat or SSI serial interface can beconnected to various signal converters as
well.
Output signals of the signal converters
The signal converters are available with thefollowing interface to the subsequent
electronics.
• TTL square-wave pulse trains• EnDat 2.2• DRIVE-CLiQ• Fanuc Serial Interface• Mitsubishi high speed interface• Yaskawa Serial Interface• Profibus• Profinet
Interpolation of the sinusoidal input
signals
In addition to performing signal conversion,
the signal converters also interpolate thesinusoidal encoder signals. This permits
finer measuring steps, resulting in higher
control quality and superior positioning
behavior.
Generation of a position value
Various signal converters feature an
integrated counter function. Starting fromthe last set reference point, an absolute
position value is generated and output tothe subsequent electronics when thereference mark is crossed.

Box design

Outputs

InputsInterface

Qty.

Interface

Qty.

« TTL

1

» 1 VPP1Model

Box design – IP65

5/10-foldIBV 101

20/25/50/100-fold

IBV 102

Without interpolation

IBV 600

25/50/100/200/400-fold

IBV 660 B

Plug design – IP40

5/10/20/25/50/100-fold

APE 371

Version for integration –IP00

5/10-fold

IDP 181

20/25/50/100-fold

IDP 182

Box design – IP65

5/10-fold

EXE 101

20/25/50/100-fold

EXE 102

Version for integration –IP00

5-foldIDP 101

Box design – IP65

2-foldIBV 6072

5/10-foldIBV 6172

Plug design» 11 µAPP

Version for integration« TTL/» 1 VPP
Adjustable2» 1 VPP1

1

5/10-fold and 20/25/50/100- IBV 6272
fold
EnDat 2.2

1

» 1 VPP

Top-hat rail design1

Box design – IP65

 16 384-fold subdivision

EIB 192

Plug design – IP40

 16 384-fold subdivision

EIB 392

2

Box design – IP65

 16 384-fold subdivision

EIB 1512

DRIVE-CLiQ

1

EnDat 2.2

1

Box design – IP65–

EIB 2391 S

Fanuc SerialInterface1» 1 VPP1

Box design – IP65

 16 384-fold subdivision

EIB 192 F

Plug design – IP40

 16 384-fold subdivision

EIB 392 F

2

Box design – IP65

 16 384-fold subdivision

EIB 1592 F

1

Box design – IP65

 16 384-fold subdivision

EIB 192 M

Plug design – IP40

 16 384-fold subdivision

EIB 392 M

2

Box design – IP65

 16 384-fold subdivision

EIB 1592 M

Mitsubishi high 1
speed interface» 1 VPPYaskawa Serial 1
Interface

EnDat 2.22)

1Plug design – IP40–

EIB 3391Y

PROFIBUS-DP 1

EnDat 2.1; EnDat 2.2

1

Top-hat rail design–

PROFIBUS
Gateway

1)

2)

Switchable

40

Design – Protection class Interpolation1) or
subdivision

Only LIC 4100, measuring step 5 nm; LIC 2100, measuring step 50 nm and 100 nm

41

Calibration according to DAkkS

The ISO 9001 quality management
standard requires quality-relevant inspection
equipment to be regularly monitored andtraceable to a national standard inconcordance with the International System
of Units (SI). HEIDENHAIN supports its
customers in this with its own calibration
lab for digital linear and angle encoders,which has been accredited since 1994.
The HEIDENHAIN calibration lab
operates in accordance with DIN EN ISO/IEC 17025 and is accredited by the German
Accreditation Body (DAkkS). HEIDENHAIN
calibration certificates granted by theaccredited lab document traceability to theInternational System of Units (SI).

Related documents

The calibration certificate from HEIDENHAIN
gives the user certainty about the accuracyof the encoder, and also certifies thetraceability to the International System ofUnits (SI) required for ISO 9001.

Length gauges from HEIDENHAIN canbe calibrated regardless of their interface.
If the measuring chain includes subsequent
electronics from HEIDENHAIN, then they
can be included in the calibration as well.

The calibration lab at HEIDENHAIN isequipped for all digital linear and angle
measuring systems requiring high accuracy:• AT, CT, MT, and ST length gauges(including in conjunction with ND 28x,
EXE, or IBV subsequent electronics)• LC, LF, LIDA, LIP, and LS linear encoders• ECN, ROC, ROD, and RON angle
encoders

The following information can be measured
and certified:• Error span for plunger retraction• Error span for a part of the measuring span
• Repeatability with five measurements(extended plunger)

Related to length gauges
BrochureInterfaces of HEIDENHAIN Encoders

Brochure
Cables and Connectors

Kabel undSteckverbinder

Contents:
Technical characteristics, cable overviews,
and cable lists

Schnittstellenvon HEIDENHAINMessgeräten

04/2018

12/2017

Brochure
Digital Readouts/Linear Encoders
For Manually Operated Machine Tools

Brochure
Evaluation Electronics
For Metrology Applications
AuswerteElektroniken

The DAkkS is a signatory to the multilateralagreement of the European co-operation
for Accreditation (EA) and to the International
Laboratory Accreditation Cooperation (ILAC)
for the mutual recognition of calibration
certificates. Calibration certificates from
HEIDENHAIN are recognized in mostindustrialized countries.

für messtechnische
AnwendungenContents:
ND, GAGE-CHEK, EIB, IK

03/2021Ͳ<ͲϭϵϬϱϳͲϬϭͲϬϬ

Positionsanzeigen
Längenmessgeräte
für handbediente
Werkzeugmaschinen

01/2020

Contents:
Digital readouts
ND, POSITIP
Linear encoders
LS

Further HEIDENHAIN products

Excerpt from a sample calibration certificate
TNC 640
Die Bahnsteuerung fürBearbeitungszentren und
Fräs-Dreh-Maschinen

02/2019

Brochures
TNC 128 Straight-Cut Control
TNC 320 Contouring Control
iTNC 530 Contouring Control
TNC 620 Contouring Control
TNC 640 Contouring Control
Contents:
Information for the user

Brochures
MANUALplus 620 Contouring Control
CNC PILOT 640 Contouring Control
MANUALplus 620
Die Steuerung für Zyklenund CNC-Drehmaschinen

Messgeräte fürelektrische Antriebe

Contents:
Rotary encoders
Angle encoders
Linear encoders

Brochure
Angle Encoders with Integral Bearing

Winkelmessgeräte
mit Eigenlagerung

März 2015

11/2017

04/2019

Contents:
Angle encoder modules
MRP2000, MRP5000, MRP8000
Angle encoder modules with integrated
torque motor SRP5000, AccurET

ModulareWinkelmessgeräte
mit optischer
Abtastungfür Werkzeugmaschinen

09/2017

Contents:
Tool touch probes
TT
Workpiece touch probes
TS

Contents:
Incremental angle encoders
ERP, ERO, ERA

09/2017

Brochure
Measuring Devices For Machine Tool
Inspection and Acceptance Testing

Brochure
Touch Probes

Tastsysteme

Contents:
Absolute angle encoders
RCN, ECN
Incremental angle encoders
RON, RPN, ROD
Brochure
Modular Angle Encoders
with Optical Scanning

Brochure
Angle Encoder Modules

Winkelmess­moduleContents:
Information for the user

Juli 2016

Brochure
Encoders for Servo Drives

42

Contents:
Information on serial interfaces,
sinusoidal signals, square-wave signals,
and commutation signals

Messgeräte
zur Abnahme und Kontrolle
von WerkzeugmaschinenContents:
Incremental linear encoders
KGM, VM

09/201743

Mastering nanometer accuracy

DR. JOHANNES HEIDENHAIN GmbH
Dr.-Johannes-Heidenhain-Straße 583301 Traunreut, Germany +49 8669 31-0
 +49 8669 32-5061
info@heidenhain.dewww.heidenhain.com
208945-2K · 5 · 05/2021 · H · Printed in Germany

HEIDENHAIN
worldwide