IFM LT80 Series User manual

Operating instructions
Electronic level and
temperature sensor
LT80xx
80264357 / 00 05 / 2019
UK

2
Contents
1 Preliminary note...................................................................................................4
1.1 Symbols used ................................................................................................4
2 Safety instructions ...............................................................................................5
3 Functions and features ........................................................................................6
3.1 Application area ............................................................................................6
3.2 Restriction of the application area ................................................................6
4 Getting started .....................................................................................................6
4.1 Example configuration 1 ................................................................................7
4.2 Example configuration 2 ................................................................................8
5 Function...............................................................................................................9
5.1 Measuring principle level ...............................................................................9
5.2 Measuring principle temperature .................................................................10
5.3 Operating principle / features of the unit......................................................10
5.3.1 Operating modes ................................................................................ 11
5.3.2 Notes on the integrated overflow prevention ......................................12
5.3.3 Display and switching functions..........................................................12
5.3.4 Offset for indicating the real level in the tank......................................14
5.3.5 Defined state in case of a fault ...........................................................14
5.3.6 Extreme value memory.......................................................................14
5.3.7 IO-Link ................................................................................................14
6 Mounting............................................................................................................15
6.1 Notes on installation instructions for operation with overflow prevention ...16
6.2 Installation instructions for operation without overflow prevention ..............17
6.2.1 Installation in the inactive zone...........................................................17
6.2.2 Installation in the active zone of the probe .........................................18
6.3 Other installation notes................................................................................19
6.3.1 Marking of the installation height .......................................................19
7 Electrical connection..........................................................................................20
8 Operating and display elements ........................................................................22
9 Menu..................................................................................................................23
9.1 Menu............................................................................................................23

3
UK
10 Parameter setting ............................................................................................24
10.1 Parameter setting in general .....................................................................24
10.2 Basic settings ...........................................................................................25
10.2.1 Assign process values to the outputs [SEL3] / [SEL4]......................25
10.2.2 Assign process value to the display [SELd]......................................25
10.2.3 Define unit of measurement for level [uni.L] .....................................26
10.2.4 Set the unit of measurement for the temperature [uni.T]..................26
10.2.5 Set the offset [OFS] ..........................................................................26
10.2.6 Set the medium [MEdI] .....................................................................26
10.2.7 Set the overflow prevention [OP]......................................................27
10.2.8 Adjust the overflow prevention [cOP]................................................28
10.3 Setting of output signals ............................................................................29
10.3.1 Set output function [oux] für OUT1...OUT4 ......................................29
10.3.2 Define the switching limits [SPx] / [rPx] (hysteresis function) ...........29
10.3.3 Define switching limits [FHx] / [FLx] (window function).....................30
10.3.4 Set set delay [dSx] ...........................................................................30
10.3.5 Set reset delay [drx] .........................................................................30
10.3.6 Define switching logic [P-n] .............................................................30
10.3.7 Define response of the outputs in case of a fault [FOUx] .................30
10.3.8 Configure display [diS]......................................................................31
10.3.9 Reset all parameters to factory settings [rES] ..................................31
11 Notes on parameter setting via IO-Link ...........................................................31
12 Operation.........................................................................................................32
12.1 Operating indicators ..................................................................................32
12.2 Read the set parameters ...........................................................................32
12.3 Read / reset extreme value memory temperature .....................................33
12.4 Fast selection level / temperature..............................................................33
12.5 Error indications.........................................................................................33
12.6 Output response in different operating states............................................34
13 Technical data..................................................................................................34
13.1 Setting values [OFS]..................................................................................34
13.2 Setting ranges switching limits for level ....................................................34
13.3 Setting ranges switching limits for temperature.........................................35
13.4 Setting values [OP]....................................................................................35
13.5 Calculation aids [OP] .................................................................................36
13.5.1 Definition "from the cover“ ................................................................36

4
1 Preliminary note
1.1 Symbols used
►Instructions
> Reaction, result
[…] Designation of keys, buttons or indications
→Cross-reference
Important note
Non-compliance may result in malfunction or interference.
Information
Supplementary note.
CAUTION!
Warning of personal injury
Slight reversible injuries may result.
13.5.2 Definition "from the bottom“..............................................................36
14 Maintenance / cleaning / change of medium ..................................................37
14.1 Maintenance information for operation without overflow prevention .........37
15 Factory setting .................................................................................................38
16 Applications......................................................................................................39
16.1 Storage tank ..............................................................................................39
16.2 Pumping station.........................................................................................40

5
UK
2 Safety instructions
• The device described is a subcomponent for integration into a system.
- The manufacturer of the system is responsible for the safety of the system.
- The system manufacturer undertakes to perform a risk assessment and to
create a documentation in accordance with legal and normative requirements
to be provided to the operator and user of the system. This documentation
must contain all necessary information and safety instructions for the operator,
the user and, if applicable, for any service personnel authorised by the
manufacturer of the system.
• Read this document before setting up the product and keep it during the entire
service life.
• The product must be suitable for the corresponding applications and
environmental conditions without any restrictions.
• Only use the product for its intended purpose (→ Functions and features).
• Only use the product for permissible media (→ Technical data).
• If the operating instructions or the technical data are not adhered to, personal
injury and/or damage to property may occur.
• The manufacturer assumes no liability or warranty for any consequences
caused by tampering with the product or incorrect use by the operator.
• Installation, electrical connection, set-up, operation and maintenance of the unit
must be carried out by qualified personnel authorised by the machine operator.
• Protect units and cables against damage.
• The unit complies with the standard EN 61000-6-4. The unit may cause radio
interference in domestic areas. If interference occurs, the user must take
appropriate actions.

6
3 Functions and features
3.1 Application area
The unit was especially designed to meet the requirements of machine tool
building. It is especially suitable for monitoring coolant emulsions (also dirty) as
well as cutting and hydraulic oils.
The unit monitors 2 process values: level and temperature.
3.2 Restriction of the application area
• The unit is not suitable for
- acids and alkalis
- hygienic and electroplating applications
- highly conductive and adhesive media (e.g. glue, shampoo)
- granulates, bulk material
- use in grinders (increased risk of formation of deposits).
• It is possible that foam of good conductivity is detected as level.
►Test proper functioning in an application test.
• For water and hydrous media with temperatures > 35 °C, install the unit in a
climatic tube (→ Accessories).
• For automatic medium detection (→ 5.3.1):
For media which are very inhomogeneous, separate from each other and thus
forming separation layers (e.g. oil layer on water), the following applies:
►Test proper functioning in an application test.
4 Getting started
For fast set-up, the example configurations described in the following can be used
for most applications. The indicated minimum distances apply exclusively to each
separately described case.

7
UK
4.1 Example configuration 1
Unit LT8022 (probe length L= 264 mm)
Medium to be detected Mineral oil
Operating mode Manual media selection with overflow prevention
(Factory setting → 5.3.1
Installation environment Metal tank, installation to Fig. 4-1
►Install unit.
►Observe the distances (x), (u) and (c):
Fig. 4-1
OP
c
x: min. 4.0 cm
u: min. 1.0 cm
c: max. 14.0 cm
►Ground sensor and tank via an electrical
connection (→ 7).
►Observe the parameter setting sequence:
- [MEdI] = [OIL.2] (→ 10.2.6)
- [OFS] = (u); e.g. (u) = 2.0 cm (→ 5.3.4)
- [OP]: Set the overflow prevention OP at a
distance (y) greater than 4.5 cm below the
mounting element.
For distances (y) smaller than 4.5 cm there
may be malfunctioning and error messages
during the adjustment process [cOP].
Step increment and setting range: (→ 13.4).
Calculation aids for [OP]: (→ 13.5).
►Adjustment of the overflow prevention OP to [cOP] (→ 10.2.8).
> The unit is ready for operation.
►Make further settings if necessary.
►Check whether the unit operates correctly.

8
4.2 Example configuration 2
Unit LT8023 (probe length L= 472 mm)
Medium to be detected Coolant emulsion
Operating mode Automatic medium detection (→ 5.3.1)
Installation environment Metal tank, installation to Fig. 4-2.
►Install unit.
►Observe the distances (x), (u) and (c):
x: min. 4.0 cm
u: min. 1.0 cm
c: max. 23.0 cm
►Ground sensor and tank via an electrical
connection (→ 7).
►Observe the maximum permitted level (b).
A distance (a2) greater than 5.0 cm must be
observed between maximum level (b) and
mounting element.
►Observe the parameter setting sequence:
- [MEdI] = [Auto] (→ 5.3.4)
- [OFS] = (u); e.g. (u) = 1.0 cm (→ 5.3.4)
- [SP1] = Set the switch point at a distance (a2)
Fig. 4-2
c
bu a2
x
Switch points [SP3] and [SP4] can be used to control the medium
temperature and to set limit values for early warning / alarm.
►Unit must be reinitialised:
►Switch the operating voltage off and on again.
> The unit is ready for operation.
►Make further settings if necessary.
►Check whether the unit operates correctly.

9
UK
5 Function
5.1 Measuring principle level
The sensor determines the level according to the capacitive measuring principle:
• An electrical field [E] is generated
and influenced by the medium to be
detected. This change to the field
causes a measurement signal that
is electronically evaluated.
• The dielectric constant of a medium
is important for its detection. Media
with a high dielectric constant
(e.g. water) generate a strong
measurement signal, media with a
low dielectric constant (e.g. oils) a
correspondingly lower signal.
• The active measurement zone of
the sensor probe is composed of
16 capacitive measuring segments.
They generate measurement
signals depending on the degree of
coverage.
Fig. 5-1
A II
E
I: Inactive zone
A: Active zone (16 active segments)
E: Electrical field
Dimensions → Technical data sheet

10
5.2 Measuring principle temperature
The temperature is detected by a Pt element at the lower end of the probe and
electronically evaluated.
• Media without water content (e.g. oils) are directly (in contact with the medium)
detected.
• Hydrous media can also be directly detected up to temperatures of 35 °C.
For temperatures > 35 °C a climatic tube has to be installed for use in
hydrous media (→ 3.2). That means that temperature detection is indirect
(not in contact with the medium).
If a climatic tube is used, considerably increased response times have to
be expected.
5.3 Operating principle / features of the unit
The unit can be installed in tanks of different sizes. Observe the notes on
installation.
4 outputs are available. They can be set separately.
OUT1 Switching signal for level limit value / IO-Link
OUT2 Switching signal for level limit value
OUT3
OUT4
Switching signal for level limit value
or
Switching signal for temperature limit
To adapt to the present application select the required operating mode.

11
UK
5.3.1 Operating modes
1. Manual media selection with overflow prevention (factory setting)
Recommended. Highest operational reliability.
The medium to be detected is set manually [MEdI]. In addition, an integrated,
independently functioning overflow prevention is available.
2. Manual media selection without overflow prevention
Medium operational reliability.
The medium to be detected is set manually as described under 1. However,
the overflow prevention is deactivated. For this reason, no adjustment is
required.
3. Automatic medium detection
Lowest operational reliability.
Each time the operating voltage is switched on, the unit adjusts itself to the
medium and the installation environment.
For automatic media detection, no overflow prevention is available.
Automatic media detection can only function properly under certain
conditions (e.g. compliance with special mounting specifications,
restrictions for operation and maintenance).

12
5.3.2 Notes on the integrated overflow prevention
With the parameter [OP] (OP = overflow prevention), one of the upper measuring
segments is defined as integrated overflow prevention.
• If the overflow prevention OP is activated, an adjustment to the installation
situation has to be made [cOP]. Otherwise, the unit is not ready for operation;
[ ] is displayed until readiness (→ 12.1).
• The overflow prevention OP can be deactivated ([OP] = [OFF]).
Deactivating the overflow prevention OP can impair the operational
reliability. For optimum operation and maximum operational reliability, we
therefore recommend to not deactivate the overflow prevention OP.
• The overflow prevention OP is the maximum limit of the measuring range. The
switch points [SPx] / [FHx] are always below [OP].
• The overflow prevention is not assigned to a separate output. It offers
additional protection and only switches if, as the level rises, the switching
output has not switched even though the corresponding switch point has been
exceeded (e.g. due to application-related malfunctions).
• Typically the overflow prevention OP reacts when the selected measuring
segment has been reached (a few mm before the set OP value).
• The overflow prevention OP replies immediately and without delay. The set
delay times (e.g. of a switch point directly below) have no effect on the overflow
prevention OP.
• The response of the overflow prevention is only indicated on the display ([Full]
and indication of the current level change every second).
5.3.3 Display and switching functions
The device displays the current level / the current temperature, optionally in
cm / inches or °C / °F. The display unit is defined by programming. The set unit of
measurement and the switching status of the switching outputs are indicated by
LEDs.
The displayed process value (level / temperature) can be changed temporarily in
the operating mode.
►Briefly press [Set].
> Display of the other unit of measurement for 30 s; the respective LED is lit.

13
UK
The unit signals via four switching outputs that set limits have been exceeded or
that the level is below the limit.
• Outputs OUT1 / OUT2 are assigned to the process value level.
• Outputs OUT3 / OUT4 are freely programmable:
Parameter [SEL3] / [SEL4] assigns the process value, level / temperature, to
the outputs OUT3 / OUT4 (→ 10.2.1).
Selectable switching functions:
• Hysteresis function / normally open (Fig. 5-2): [oux] = [Hno].
• Hysteresis function / normally closed (Fig. 5-2): [oux] = [Hnc].
First the set point [SPx] is set, then the reset point [rPx] with the requested
difference.
The hysteresis for the overflow prevention OP is fixed.
• Window function / normally open (Fig. 5-3): [oux] = [Fno].
• Window function / normally closed (Fig. 5-3): [oux] = [Fnc].
The width of the window can be set by means of the difference between
[FHx] and [FLx]. [FHx] = upper value, [FLx] = lower value.
Fig. 5-2 Fig. 5-3
SP
rP
L / T
t
L / T
FH
FL
1
0
1
0
FE
Fno
Fnc
L:
T:
Level
Temperature
HY:
FE:
Hysteresis
Window

14
5.3.4 Offset for indicating the real level in the tank
The distance between tank bottom and lower edge of the probe can be entered as
offset value [OFS]. So display and switch points refer to the actual level (point of
reference = tank bottom)
For [OFS] = [0]: The reference point is the lower edge of the measuring
probe.
The set offset only refers to the display on the unit. It has no effect on
the process value transmitted via IO-Link. The OFS parameter, however,
is correctly transmitted via IO-Link and can therefore be taken into
consideration.
More information → 5.3.7.
5.3.5 Defined state in case of a fault
In case of a fault a state can be defined for each output. If a fault is detected or if
the signal quality is below a minimum value, the outputs pass into a defined state.
For this case the response of the outputs can be set via the parameters [FOU1]...
[FOU4] [FOU4] (→ 5.3.5)
5.3.6 Extreme value memory
The minimum and maximum values of the temperatures occurred since the last
memory reset can be retrieved via the menu items [Lo.T] and [Hi.T].
5.3.7 IO-Link
This unit has an IO-Link communication interface which enables direct access to
process and diagnostic data.
In addition it is possible to set the parameters of the unit during operation.
Operation of the unit via IO-Link interface requires an IO-Link capable module
(IO-Link master).
With a PC, suitable IO-Link software and an IO-Link adapter cable communication
is possible when the system is not in operation.
The IODDs necessary for the configuration of the unit, detailed information about
process data structure, diagnostic information, parameter addresses and the
necessary information about the required IO-Link hardware and software can be
found at www.ifm.com.

15
UK
6 Mounting
CAUTION!
The surface of the unit may get hot if the switching outputs are
operated at maximum load.
> Risk of burns
►Do not touch the unit
►Protect the housing against contact with flammable substances
and unintentional contact.
Fig. 6-1
OP
c
L:
M:
c:
Probe length
Zone for mounting elements
Maximum outside length
u ... y:
OP:
B:
Minimum distances
Overflow prevention
Metal object inside the tank
Table 6-1
LT8022 LT8023 LT8024
[cm] [inch] [cm] [inch] [cm] [inch]
L (rod length) 26.4 10.4 47.2 18.6 72.8 28.7
M (mounting zone) 14.0 5.5 23.0 9.1 36.0 14.2
c (max. outside length)*
* Applies to installation as shown (wall thickness of the tank lid was neglected;
mounting element does not protrude inside the tank).
Otherwise note mounting zone M.

16
6.1 Notes on installation instructions for operation with
overflow prevention
[MEdI] = [CLW..] or [OIL..];
[OP] = [value ...] (overflow prevention OP activated)
It is permitted to fix the mounting elements within the mounting zone (M)
(Fig. 6-1).
►Observe the maximum permitted outside length (c) according to Table 6-1.
►Observe the minimum distances according to Fig. 6-1 and Table 6-2.
►Observe the notes on the integrated overflow prevention OP.
The overflow prevention (OP) must:
1. be below the mounting element
2. be set at a minimum distance (y) to it.
The minimum distance is measured between upper edge mounting
element and OP value .
Table 6-2
MEdI = CLW.1 MEdI = CLW.2, OIL.1 MEdI = OIL.2
[cm] [inch] [cm] [inch] [cm] [inch]
x 2.0 0.8 3.0 1.2 4.0 1.6
u 1.0 0.4 1.0 0.4 1.0 0.4
y (LT8022) 2.5 1.0 3.5 1.4 4.5 1.8
y (LT8023) 4.5 1.8 5.5 2.2 6.5 2.6
y (LT8024) 6.0 2.4 7.0 2.8 8.0 3.2
v 4.5 1.8 4.5 1.8 4.5 1.8
w 4.0 1.6 5.0 2.0 6.0 2.4
Calculation aids for [OP]: → 13.5

17
UK
6.2 Installation instructions for operation without overflow
prevention
[MEdI] = [Auto] or [OP] = [OFF] (overflow prevention OP deactivated)
6.2.1 Installation in the inactive zone
Between the maximum level (b1) and the inactive zone (I1), minimum
distance (a1) must be adhered to (see Fig. 6-2 and Table 6-3).
►Fix the unit using mounting elements
in the inactive zone (I1). The outside
length (c) must not exceed (I1) (Table
6-3).
►Ensure that the maximum level (b1)
is not exceeded after completed
installation (Table 6-3).
►Observe further minimum distances
according to Table 6-4.
Fig. 6-2
A I1
c
I2
b1 a1
x
u
I1 / I2: Inactive zones
A: Active zone
a1: Minimum distance between the
inactive zone (I1) and the maximum
level (b1)
b1: Max. level from the lower edge of the
sensor (without offset)
c: outside length
Table 6-3
LT8022 LT8023 LT8024
[cm] [inch] [cm] [inch] [cm] [inch]
I1 5.3 2.1 6.0 2.4 10.4 4.1
A 19.5 7.7 39.0 15.4 58.5 23.0
a1 1.0 0.4 1.5 0.6 2.5 1
b1 20.0 7.9 39.5 15.6 59.5 23.4

18
6.2.2 Installation in the active zone of the probe
The minimum distance (a2) must be observed between the maximum level
(b2) and the mounting element (a2) (Fig. 6.3 and Table 6-4).
►Fix mounting elements in the mounting
zone (M) (fig. 6-1). Adhere to maximum
permitted outside length (c) (see 6-1).
►Ensure that the maximum level (b2)
is not exceeded after completed
installation:
(b2) = (L) - (c) - (a2) (without offset)
►Observe further minimum distances
according to Table 6-4.
►
Fig. 6-3
c
b2
L
u a2
x
c: outside length
(max. outside length Table 6-1)
a2: Minimum distance between the
mounting element and the maximum
level (b).
b2: Max. level from the lower edge of
the sensor.
Table 6-4
MEdI = CLW.1 MEdI = CLW.2, OIL.1 MEdI = OIL.2 / Auto
[cm] [inch] [cm] [inch] [cm] [inch]
x 2.0 0.8 3.0 1.2 4.0 1.6
u 1.0 0.4 1.0 0.4 1.0 0.4
a2 (LT8022) 2.0 0.8 2.5 1.0 3.0 1.2
a2 (LT8023) 4.0 1.6 4.5 1.8 5.0 2.0
a2 (LT8024) 6.0 2.4 7.0 2.8 8.0 3.2
v *)4.5 1.8 4.5 1.8 4.5 1.8
w *)4.0 1.6 5.0 2.0 6.0 2.4
*)→ Fig. 6-1.

19
UK
In case of automatic medium detection [MEdI] = [Auto] or deactivated
overflow prevention [OP] = [OFF], the sensor reinitialises itself each time it
is switched on and makes adjustments to the medium and the installation
environment. The active zone / measuring range must not be completely
covered by the medium. The indicated minimum distances ensure this. Too
short a distance may lead to maladjustments and malfunctions.
6.3 Other installation notes
• For mounting in plastic pipes/plastic tanks, the inside (pipe) diameter must at
least be 12.0 cm (4.8 inches). Install sensor in the centre.
• For mounting in metal pipes the inside pipe diameter (d) must be at least:
Table 6-5
MEdI = CLW.1 MEdI = CLW.2, OIL.1 MEdI = OIL.2, AUTO
[cm] [inch] [cm] [inch] [cm] [inch]
d 4.0 1.6 6.0 2.4 10.0 4.0
6.3.1 Marking of the installation height
►Fix the set installation height with the supplied
stainless steel tube clip.
If the sensor is removed from the fixture for
maintenance reasons, the clip serves as a
limit stop when remounting the sensor. Thus
an inadvertent maladjustment of the sensor is
excluded. This is in particular necessary for the
correct function of the overflow prevention.
►Fit the stainless steel tube clip using pliers.
►Ensure a safe fit.
►To remove the clip it has to be destroyed.

20
7 Electrical connection
The unit must be connected by a qualified electrician.
The national and international regulations for the installation of electrical
equipment must be adhered to.
Voltage supply according to EN 50178, SELV, PELV.
►Disconnect power.
►Connect the unit as follows:
Core colours
6
2
1
4
57
3
OUT 4
OUT 1
OUT 3
L+
OUT 2
L
BU
BK
WH
GY
PK
VT
BN
3
4
2
5
6
7
1
Pin Socket ifm to
DIN 47100
1 BN brown white
2 WH white brown
3 BU blue green
4 BK black yellow
5 GY grey grey
6 PK pink pink
7 VT violet blue
OUT1: / IO-Link
OUT2: Switching output (level)
OUT3: Switching output (level / temperature)
OUT4: Switching output (level / temperature)
Colours to ifm
Example circuits
4 x positive switching 4 x negative switching
L+
BU
BN
3
4 BK
7
6
1
L
PK
VT
2 WH
GY5
4: OUT1
2: OUT2
5: OUT3
6: OUT4
L+
BU
BN
3
4 BK
6
1
PK
L
2 WH
GY5
4: OUT1
2: OUT2
5: OUT3
6: OUT4
7VT