Product Information

LIF 471 V
LIF 481 V
LIF 481 U
Exposed Linear Encoder for
High- and Ultrahigh-Vacuum
Applications

03/2024

LIF 471 V/LIF 481 V/LIF 481 U
Incremental linear encoder for high- and ultrahigh-vacuum applications• Special, vacuum-compatible version• For measuring steps of down to 2 nm
• Position detection through homing track and limit switches
Illustration without limit plateand fixed point



 60
















  60



LIF 401 R

Measuring standard*
Coefficient of linear expansion

SUPRADUR phase grating on Zerodur glass ceramic or glass; grating period: 8 µm–6 –1–6 –1
Þtherm = (0±0.1) · 10 K (Zerodur glass-ceramic); Þtherm ≈ 8 · 10 K (glass)Accuracy grade±3 µm

Baseline error≤ ±0.225 µm/5 mm

Measuring length (ML)*in mm  70	 120	 170	 220	 270	 320	 370	 420	 470	 520	 570	 620	 670720	 770	 820	 870	 920	 970 1020 1140 1240 1340 1440 1540 1640

Reference marks

One at midpoint of measuring length

Mass

0.8 g + 0.08 g/mm of measuring length

Scanning head

LIF 48 V/LIF 48 U

LIF 47 VInterface» 1 VPP TTLIntegrated interpolation*
Signal period–
4 µm

5-fold
0.8 µmCutoff frequency

 1 MHz–Scanning frequency*–

Edge separation a     

 



Scale


    
–

 




Illustration without fixing clamps,limit plates, and fixed point  – 



20-fold
0.2 µm50-fold
0.08 µm

100-fold
0.04 µm≤ 500 kHz≤ 250 kHz≤ 125 kHz≤ 250 kHz≤ 125 kHz≤ 62.5 kHz≤ 250 kHz≤ 125 kHz≤ 62.5 kHz≤ 100 kHz≤ 50 kHz≤ 25 kHz≤ 50 kHz≤ 25 kHz≤ 12.5 kHz–≥ 0.080 µs≥ 0.175 µs≥ 0.370 µs≥ 0.080 µs≥ 0.175 µs≥ 0.370 µs≥ 0.040 µs≥ 0.080 µs≥ 0.175 µs≥ 0.040 µs≥ 0.080 µs≥ 0.175 µs≥ 0.040 µs≥ 0.080 µs≥ 0.175 µs

Traversing speed≤ 240 m/min≤ 120 m/min≤ 60 m/min≤ 30 m/min≤ 60 m/min≤ 30 m/min≤ 15 m/min≤ 60 m/min≤ 30 m/min≤ 15 m/min≤ 24 m/min≤ 12 m/min≤ 6 m/min≤ 12 m/min≤ 6 m/min≤ 3 m/minInterpolation error
RMS position noise±12 nm
0.6 nm (1 MHz2))–Electrical connection*• Interface electronics outside of vacuum:
Cable (0.5 m, 1 m, 2 m or 2.5 m) up to vacuum feed-through; cable (0.5 m) up to15-pin D-sub connector with built-in interface electronics• Interface electronics inside of high vacuum:
Cable (0.5 m, 1 m, 2 m or 3 m) with 15-pin D-sub connector with built-in interface electronics

Cable length

See interface description; however:
Incremental: ≤ 30 m; Homing, Limit: ≤ 10 m (with HEIDENHAIN cable)

Supply voltage

DC 5 V ±0.25 V

Current consumption< 150 mA

Vibration 55 Hz to 2000 Hz
Shock 11 ms≤ 400 m/s (EN 60068-2-6)≤ 500 m/s2 (EN 60068-2-27)

Operating temperature

0 °C to 50 °C

Bake-out temperature

100 °C (LIF 4x V); 120 °C (LIF 48 U)

PCB material

FR4–3 dB



10-fold
0.4 µm  

  

1)  
Position of stop pins       

ML/2 ±0.5

ML/2 ±0.5   
L = Scale length
F = Machine guideway* = Maximum change during operation
ML = Measuring length
LI = Limit mark, adjustable
H = Switch for homing track, homing switching edges
Ho = Trigger point for homing
R = Position of reference markS = Beginning of measuring length
1 = Optical centerline
2 = Gap between scanning head / scale
3 = Positive direction of measurement
4 = Clearance set with spacer shim
5 = Additional pair of fixing clamps, depending on ML
6 = Vacuum adhesive, dries at room temperature in 24 h
7 = Mounting surface for scanning head
8 = Fixed-point element(12.5)

Ho(13.5)

1.2±0.3

22


Limit
LI1 ±0.25

LI2 ±0.25

HomingMass								Scanning head
CableConnector< 165 mA (without load)
29g
38 g/m75 g* Please select when ordering
1)
With TTL: maximum traversing speed during referencing: 9.6 m/min (40 kHz)2)
–3 dB cutoff frequency of subsequent electronics
Product Information: LIF 471 V/LIF 481 V/LIF 481 U   03/2024

Product Information: LIF 471 V/LIF 481 V/LIF 481 U   03/2024

Encoders for use in a vacuumElectrical connection

These vacuum-compatible encoders
feature the following characteristics:• Air vents• Specialized cleaning and packaging• Cable with PTFE insulation and tin-plated
copper braiding

High vacuum

10–10 Cable length: 0.5 m ... 3 mInterface electronics inside ofhigh vacuum:
The scanning head cable has a 15-pin
D-sub connector that contains the interface
electronics. A vacuum feed-through (15-pin
D-sub on DN63CF flange) and an extension
cable are available as accessories.

10–9
Partial pressure in mbar

Residual gas analysis of HEIDENHAINvacuum components
The influence of vacuum components on
the quality of a vacuum can be determinedthrough residual gas analyses. In theseanalyses, a sample in a vacuum chamber ispumped out to at least 10–6 mbar
(turbomolecular pump, pumping speed
15 l/s to 200 l/s). The residual gases aremeasured with a mass spectrometer(Pfeiffer QMA 200) and an absolutepressure sensor (VACOM ATMION). The
outgassing behavior of the examinedsample can then be deduced by subtracting
the typical residual gases of the emptychamber. The amount of remaining residual
gases depends not only on the cleanlinessof the sample and the tested materials, butalso on the pump type used and its
pumping speed. The higher the pumping
speed for the measurement is, and thelonger the gas is pumped out, the lower
the amount of residual gases will be.

The LIF 471 V/LIF 481 V is available withtwo different cable versions:

10–8

10–11

10–12
0

10

2030

4050
Mass in u60

70

180

190

200

The spectrum was determined with three scanning heads at an absolute pressure of 1.5–7 mbar anda pumping speed of 92 l/s.

To attain the lowest possible outgassing
values, HEIDENHAIN recommends baking
at 100 °C for 48 hours under high vacuum
conditions.

Interface electronics outside ofhigh vacuum:
The scanning head cable has ahigh-vacuum-compatible roundconnector. Included with theencoder are the corresponding
high-vacuum feed-through and theadapter cable with a 15-pin D-sub
connector with integrated interface
electronics.

Vacuum Air

Ultrahigh vacuum

The LIF 481 U is available with thefollowing cable feed-through:Residual gas analysis
The spectrum shown is the typical resultfor an LIF 48 V, LIF 47 V or LIF 48 U scanninghead with a one-meter cable and APEinterface unit (connector) after having been
baked in a high vacuum for 24 hours at100 °C.

When used in an ultrahigh vacuum,
the encoder must not contain any
electronic components such as
signal converters. The LIF 481 U isequipped with a cable and an
ultrahigh-vacuum-compatible D-sub
connector. Included in delivery is anadapter cable with a signal converter
integrated into the D-sub connector.
A vacuum feed-through (15-pinD-sub connector on DN63CF flange)and an extension cable are available
as accessories.

LIF 481 U variant

Product Information: LIF 471 V/LIF 481 V/LIF 481 U   03/2024

Product Information: LIF 471 V/LIF 481 V/LIF 481 U   03/2024

Vacuum Air

Status LED

The built-in signal-quality indicator permits
both a reliable assessment of theincremental signals and inspection of thereference-mark signal. The quality of theincremental signals is indicated by arange of colors, permitting quite detailed
signal-quality differentiation. The tolerance
conformity of the reference-mark signal isshown by means of a pass/fail indicator.
LED indicator for reference-mark signal(operating check)
When the reference mark is traversed, theLED briefly lights up in red or blue: Out of tolerance Within tolerance

LED indicator for incremental signals
LED color

Quality of the scanningsignals

Optimal



Good



AcceptableUnsatisfactory

Signal-quality indicator in the signal converter(for variants in air)

Pin layout
15-pin D-sub connector

Power supply« TTL» 1 VPP

Incremental signals

Other signals

412210193111471386UP

Sensor
5V0VSensor0VUa1¢

Ua2£

Ua0

¥HL

A+A–B+B–R+R–Assigned

GrayPinkRedBlack

Violet Green/ Yellow/ Yellow
Black BlackBrown/ BlueGreenWhite/ White Brown GreenGreen155PWT1) Vacant
As- Vacantsigned/Shield on housing; UP = Power supply voltage
Sensor: The sense line is connected in the encoder with the corresponding power supply line.
Vacant pins or wires must not be used.
1)
TTL/11 µAPP conversion for the PWTDR. JOHANNES HEIDENHAIN GmbHDr.-Johannes-Heidenhain-Straße 583301 Traunreut, Germany +49 8669 31-0 +49 8669 32-5061
info@heidenhain.dewww.heidenhain.com

662692 · 03 · A · 02 · 03/2024 · PDF

This Product Information document supersedes all previous editions, which thereby
become invalid. The basis for ordering from HEIDENHAIN is always the Product
Information document edition valid when the order is placed.

Further information:
Comply with the requirements described in the following documents to ensure correctand intended operation:• Brochure: Exposed Linear Encoders
ID 208960-xx• Technical Information: Linear Encoders for Vacuum Technology
ID 627568-xx