With regard to the supply of products, the current issue of the following document is applicable:
The General Terms of Delivery for Products and Services of the Electrical Industry,
published by the Central Association of the Electrical Industry (Zentralverband Elektrotechnik und
Elektroindustrie (ZVEI) e.V.) in its most recent version as well as the supplementary clause:
"Expanded reservation of proprietorship".
Application
The device is a pressure sensor for hydrostatic level measurement.
Pepperl+Fuchs offers three different versions of the device:
• Device with a stainless steel housing, external diameter of 22 mm (0.87 inch):
This version is excellently suited to drinking water applications and for use in bore holes and wells with
small diameters
• Device with a stainless steel housing, external diameter of 42 mm (1.65 inch):
Heavy-duty version and easy to clean thanks to flush-mounted process isolating diaphragm, ideally
suited to wastewater and wastewater treatment plants
• Device with plastic insulation, external diameter of 29 mm (1.14 inch):
Robust version for use in salt water and excellently suited to applications on ships (e. g. ballast water
tanks)
Your benefits
• High resistance to overload
• High-precision, robust ceramic measuring cell with long-term stability
• Climate proofed sensor thanks to completely potted electronics and 2-filter pressure compensation
system
• Simultaneous measurement of level and temperature with optionally integrated Pt100 resistance
thermometer
• Accuracy
•Standard reference accuracy ±0.2 %
•Plantinum version ±0.1 %
• Automatic density compensation to increase accuracy
• Usage in drinking water: KTW, NSF, ACS
• Approvals: ATEX, FM, CSA
• Extensive range of accessories provides complete measuring point solutions
This document contains symbols for the identification of warning messages and of informative
messages.
Warning Messages
You will find warning messages, whenever dangers may arise from your actions. It is
mandatory that you observe these warning messages for your personal safety and in order to
avoid property damage.
Depending on the risk level, the warning messages are displayed in descending order as
follows:
Danger!
This symbol indicates an imminent danger.
Non-observance will result in personal injury or death.
Warning!
This symbol indicates a possible fault or danger.
Non-observance may cause personal injury or serious property damage.
Caution!
This symbol indicates a possible fault.
Non-observance could interrupt the device and any connected systems and plants, or result in
their complete failure.
Informative Symbols
Note!
This symbol brings important information to your attention.
Action
This symbol indicates a paragraph with instructions. You are prompted to perform an action or
a sequence of actions.
2017-02
6
Level Probe LGC2
)
*
Important Document Information
1.1.2Electrical symbols
SymbolMeaning
Table 1.1
Direct current
A terminal to which DC voltage is applied or through which direct
current flows.
Alternating current
A terminal to which alternating voltage is applied or through which
alternating current flows.
Direct current and alternating current
•A terminal to which alternating voltage or DC voltage is applied.
•A terminal through which alternating current or direct current
flows.
Ground connection
A grounded terminal which, as far as the operator is concerned, is
grounded via a grounding system.
Protective ground connection
A terminal which must be connected to ground prior to establishing
any other connections.
Equipotential connection
A connection that has to be connected to the plant grounding
system: This may be a potential equalization line or a star grounding
system depending on national or company codes of practice.
1.1.3Symbols for certain types of information
SymbolMeaning
Allowed
Indicates procedures, processes or actions that are allowed.
Preferred
Indicates procedures, processes or actions that are preferred.
Forbidden
Indicates procedures, processes or actions that are forbidden.
1., 2., 3. ...Series of steps
Result of a sequence of actions
Visual check
Table 1.2
2017-02
7
Level Probe LGC2
URLOPLMWP
LRL
0
p
LRV
URV
1
2
3
4
Important Document Information
1.1.4Symbols in graphics
SymbolMeaning
1, 2, 3 ...Item numbers
,…,1. 2. 3.
A, B, C, ...Views
A-A, B-B, C-C, ...Sections
-
.
Table 1.3
1.2Terms and Abbreviations
Series of steps
Hazardous area
Indicates a hazardous area.
Safe area (non-hazardous area)
Indicates a non-hazardous location.
Figure 1.1
8
2017-02
Level Probe LGC2
Important Document Information
PositionTerms/abbreviationsExplanation
1OPLThe OPL (over pressure limit = sensor overload limit) for
2MWPThe MWP (maximum working pressure) for the sensors
3Maximum sensor
measuring range
4Calibrated/adjusted
span
p–Pressure
–LRLLower range limit
–URLUpper range limit
–LRVLower range value
–URVUpper range value
–TD (Turn down)Turn down: Example see the following section.
–PEPolyethylene
–FEPFluorinated ethylene propylene
Table 1.4
the measuring device depends on the lowest-rated
element, with regard to pressure, of the selected
components, i. e. the process connection has to be taken
into consideration in addition to the measuring cell. Also
observe pressure-temperature dependency. For the
relevant standards and additional notes, see the
"Pressure specifications" section.
The OPL may only be applied for a limited period of time.
depends on the lowest-rated element, with regard to
pressure, of the selected components, i. e. the process
connection has to be taken into consideration in addition
to the measuring cell. Also observe pressuretemperature dependency. For the relevant standards
and additional notes, see the "Pressure specifications"
section.
The MWP may be applied at the device for an unlimited
period. The MWP can also be found on the nameplate.
Span between LRL and URL
This sensor measuring range is equivalent to the
maximum calibratable/adjustable span.
Span between LRV and URV
Factory setting: 0 to URL
Other calibrated spans can be ordered as customized
spans.
2017-02
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Level Probe LGC2
LRV
URLURV
LRL
1 = 2
3
Important Document Information
1.3Turn down calculation
Figure 1.2
1Calibrated/adjusted span
2Zero point-based span (4 to 20 mA analog: customer-specific span can only be set at the
factory when ordered)
3Upper range value
Example
• Sensor: 10 bar (150 psi)
• Upper range value (URL) = 10 bar (150 psi)
• Calibrated/adjusted span: 0 to 5 bar (0 to 75 psi)
• Lower range value (LRV) = 0 bar (0 psi)
• Upper range value (URV) = 5 bar (75 psi)
TD = URL/(URV – LRV)
TD = 10 bar (150 psi)/(5 bar (75 psi) – 0bar (0psi)) = 2
In this example, the TD is 2:1. This span is based on the zero point.
10
2017-02
Level Probe LGC2
Function and System Design
2Function and System Design
2.1Device Versions
Caution!
Gas loss when using the device in biogas plants
The device is not suitable for use in biogas plants since the gases can diffuse through the
elastomers (seals, probe connection).
Use the devices LHCR-51, LHCS-51 for applications involving biogas.
Outer diameter22 mm (0.87 inch)42 mm (1.65 inch)max. 29 mm (1.14 inch)
Field of applicationHydrostatic level
Process connection
(extension cable)
Probe connectionPE, FEP
Seals•FKM Viton
Measuring ranges•Relative pressure: 0 to 0.1 bar (0 to 1.5 psi) to
Overloadto 40 bar (600 psi)to 25 bar (375 psi)
Process temperature
range
Reference accuracy•±0.2 % of the set span
Supply voltage10.5 to 35 V DC, Ex: 10.5 to 30 V DC
Output4 to 20 mA Analog
2017-02
measurement in deep
wells e. g. drinking water
•Suspension clamp
•Cable mounting screw with G1-1/2A thread or NPT1-1/2 thread
•EPDM
0 to 20 bar (0 to 300 psi)
•Absolute pressure: 0 to 2 bar (0 to 30 psi) to
0 to 20 bar (0 to 300 psi)
•The following output units can be configured: %, mbar, bar, kPa, MPa, mm H2O,
m H2O, inch H2O, foot H2O, psi and numerous level units.
-10 to +70 °C (+14 to +158 °F)0 to +50 °C (+32 to +122 °F)
•optional: ±0.1 % of the set span (Platinum version)
1
Hydrostatic level
measurement in
wastewater
FKM Viton•FKM Viton
Hydrostatic level
measurement in saltwater
•EPDM
•Relative pressure:
0 to 0.1 bar (0 to 1.5 psi)
to 0 to 4 bar (0 to 60 psi)
•Absolute pressure:
0 to 2 bar (0 to 30 psi) to
0 to 4 bar (0 to 60 psi)
1
11
Level Probe LGC2
Function and System Design
Outer diameter22 mm (0.87 inch)42 mm (1.65 inch)max. 29 mm (1.14 inch)
OptionsDrinking water approval–
•Wide range of approvals, including ATEX, FM, CSA
•Numerous accessories
•Integrated Pt100 resistance thermometer and HUT temperature head transmitter
(4 to 20 mA)
Specialties•High-precision, robust ceramic measuring cell with long-term stability
•Automatic density compensation
•Customer-specific cable marking
1
Recommended for drinking water applications, not suitable for use in hazardous areas.
12
2017-02
Level Probe LGC2
.
.
2
1
ρ x g
h ~ p
h =
p
p
hydr
p
atm
p
atm
p = p +
atmhydr.
p
h
p = p + p
atmhydr
p
atm
Rel.: p= (p + p) -
sensatmhydr.
Abs.: p= (p +
sensatmhydr.
p)
p
atm
Function and System Design
2.2Measuring Principle
The ceramic measuring cell is a dry measuring cell i. e. the pressure acts directly on the robust,
ceramic process isolating diaphragm of the device. Changes in air pressure are guided via a
pressure compensation tube through the extension cable to the rear of the ceramic process
isolating diaphragm and are compensated for. A pressure-dependent change in capacitance,
caused by the movement of the process isolating diaphragm, is measured at the electrodes of
the ceramic carrier. The electronics unit then converts this to a signal that is proportional to the
pressure and linear to the level.
Temperature measurement with optional Pt100 resistance
thermometer
For simultaneous measurement of level and temperature, Pepperl+Fuchs offers the device
with an optional 4-wire Pt100 resistance thermometer. The Pt100 ressistance thermometer is
categorized as Accuracy Class B as per DIN/EN 60751.
Hydrostatic pressure
Atmospheric pressure
Pressure displayed on the sensor
1
2017-02
1
Not for use in hazardous areas.
13
Level Probe LGC2
ON
1
2
E
-+-
%
Function and System Design
Temperature measurement with optional Pt100 resistance thermometer
and HUT temperature head transmitter
To convert the temperature signal to an analog, scalable 4 to 20 mA output signal,
Pepperl+Fuchs also offers the HUT temperature head transmitter. Ordering information:
product structure, feature "Accessories", option "XP".
2.3Measuring System
Application Examples
As standard, the complete measuring system consists of a level probe and a transmitter power
supply unit with a supply voltage of 10.5 to 30 V DC (hazardous areas) or 10.5 to 35 V DC
(non-hazardous areas).
Possible measuring point solutions with a signal converter and evaluation device:
2
1
A
3
3
2
1
5
6
4
KFD2-CR4-1
PWR
9107
12
11
13 15
14
B
ON
3
132465
KFD2-CRG2-
1.D
PWR
FLT
12
OUT
RS232
9137
8
15
14
19 21
20
12401.5
ESC
OK
121610
11
18
17
22 24
23
E
-+-
4
5
ON
1
2
4
5
C
1
3
4
5
D
4
5
Figure 2.2
3
1Level probe LGC
24to20mA
3 and 4 Surge protection device, e. g. for DIN mounting rail mounting, selection in accordance
with supply voltage, not for use in hazardous areas
5Power supply
14
1
Not for use in hazardous areas.
2017-02
Level Probe LGC2
E
F
2
3
4
3
4
5
5
5
6
6
6
7
7
7
1
2
5
12401.5
E
-+-
ON
1
2
ON
1
2
E
-+-
ON
1
2
E
-+-
ONON
1
2
E
-+-
ONON
1
2
E
-+-
%
ESC
OK
KFD2-CRG2-
1.D
RS232
PWR
12
FLT
OUT
19 21
15
9137
20
14
8
22 24
18
121610
23
17
11
132465
ESC
OK
KFD2-CRG2-
1.D
RS232
PWR
12
FLT
OUT
19 21
15
9137
20
14
8
22 24
18
121610
23
17
11
132465
Function and System Design
A: Easy and cost-effective measuring point solution: power supplied to the device in
hazardous and non-hazardous areas via a transmitter power supply. Power supply and
additional control of two appliances, such as pumps, via a trip amplifier with local display.
B: An evaluation device offers power supply, local display and two switch outputs.
C: If several pumps are used, the pump service life can be prolonged by alternate switching.
With alternating pump control, the pump which was out of service for the longest period of time
is switched on. Use a suitable evaluation device for this application.
D: State-of-the-art recording technology with graphic display recorders for documentation,
monitoring, visualization and archiving purposes.
Application Examples with the Pt100 Resistance Thermometer
As standard, the complete measuring system consists of a level probe and a transmitter power
supply unit with a supply voltage of 10.5 to 30 V DC (hazardous areas) or 10.5 to 35 V DC
(non-hazardous areas).
Possible measuring point solutions with a signal converter and evaluation device:
Figure 2.3
2017-02
15
Level Probe LGC2
Function and System Design
1Level probe LGC
2Connection for integrated Pt100 in the device
3Temperature for 4 to 20 mA
4Level for 4 to 20 mA
5Surge protection device, e. g. on the sensor side for field installation: for DIN mounting
rail mounting, selection in accordance with supply voltage, not for use in hazardous areas
6Surge protection device, e. g. for DIN mounting rail mounting, selection in accordance
with supply voltage, not for use in hazardous areas
7Power supply
E: If you wish to measure, display and evaluate the temperature as well as the level, e. g. to
monitor the temperature in fresh water for the purpose of detecting temperature limits for germ
formation, the options available to you include the following: The optionally available HUT
temperature head transmitter can convert the Pt100 signal into a 4 to 20 mA signal and
transfer it to any commonly used evaluation device. Some evaluation devices also offer a
direct input for the Pt100 signal.
F: If you wish to record and evaluate the level and temperature measured value with one
device, use evaluation devices with two inputs. It is even possible to mathematically link the
input signals with this unit.