Endress+Hauser Turbimax CUS51D User manual

Products Solutions Services
Operating Instructions
Turbimax CUS51D
Sensor for turbidity and solids content
BA00461C/07/EN/20.23-00
71623201
2023-07-08

Turbimax CUS51D Table of contents
Endress+Hauser 3
Table of contents
1 About this document ................ 4
1.1 Safety information ...................... 4
1.2 Symbols used .......................... 4
1.3 Symbols on the device ................... 4
1.4 Documentation ........................ 5
2 Basic safety instructions ............ 6
2.1 Requirements of the personnel ............. 6
2.2 Intended use .......................... 6
2.3 Workplace safety ....................... 6
2.4 Operational safety ...................... 7
2.5 Product safety ......................... 7
3 Product description ................. 8
3.1 Product design ......................... 8
4 Incoming acceptance and product
identification ..................... 13
4.1 Incoming acceptance ................... 13
4.2 Product identification ................... 13
4.3 Scope of delivery ...................... 14
4.4 Certificates and approvals ............... 14
5 Mounting ......................... 15
5.1 Mounting requirements ................. 15
5.2 Mounting the sensor ................... 16
5.3 Post-mounting check ................... 23
6 Electrical connection .............. 24
6.1 Connecting the sensor .................. 24
6.2 Ensuring the degree of protection .......... 25
6.3 Post-connection check .................. 26
7 Commissioning .................... 27
7.1 Function check ....................... 27
8 Operation ......................... 28
8.1 Adapting the measuring device to the process
conditions ........................... 28
9 Diagnostics and troubleshooting ... 38
9.1 General troubleshooting ................. 38
10 Maintenance ...................... 39
10.1 Maintenance tasks ..................... 39
11 Repair ............................ 40
11.1 General notes ........................ 40
11.2 Spare parts .......................... 40
11.3 Return .............................. 40
11.4 Disposal ............................ 40
12 Accessories ....................... 41
12.1 Device-specific accessories ............... 41
13 Technical data .................... 43
13.1 Input ............................... 43
13.2 Energy supply ........................ 43
13.3 Performance characteristics .............. 43
13.4 Environment ......................... 44
13.5 Process ............................. 45
13.6 Mechanical construction ................ 45
Index .................................. 46

About this document Turbimax CUS51D
4 Endress+Hauser
1 About this document
1.1 Safety information
Structure of information Meaning
LDANGER
Causes (/consequences)
If necessary, Consequences of
non-compliance (if applicable)
‣Corrective action
This symbol alerts you to a dangerous situation.
Failure to avoid the dangerous situation will result in a fatal or serious
injury.
LWARNING
Causes (/consequences)
If necessary, Consequences of
non-compliance (if applicable)
‣Corrective action
This symbol alerts you to a dangerous situation.
Failure to avoid the dangerous situation can result in a fatal or serious
injury.
LCAUTION
Causes (/consequences)
If necessary, Consequences of
non-compliance (if applicable)
‣Corrective action
This symbol alerts you to a dangerous situation.
Failure to avoid this situation can result in minor or more serious injuries.
NOTICE
Cause/situation
If necessary, Consequences of
non-compliance (if applicable)
‣Action/note
This symbol alerts you to situations which may result in damage to
property.
1.2 Symbols used
Additional information, tips
Permitted
Recommended
Forbidden or not recommended
Reference to device documentation
Reference to page
Reference to graphic
 Result of a step
1.3 Symbols on the device
Symbol Meaning
Reference to device documentation
Do not dispose of products bearing this marking as unsorted municipal
waste. Instead, return them to the manufacturer for disposal under the
applicable conditions.

Turbimax CUS51D About this document
Endress+Hauser 5
1.4 Documentation
The following manuals, which complement these Operating Instructions, can be found on
the product pages on the Internet:
Technical Information Turbimax CUS51D, TI00461C

Basic safety instructions Turbimax CUS51D
6 Endress+Hauser
2 Basic safety instructions
2.1 Requirements of the personnel
• Installation, commissioning, operation and maintenance of the measuring system may
be carried out only by specially trained technical personnel.
• The technical personnel must be authorized by the plant operator to carry out the
specified activities.
• The electrical connection may be performed only by an electrical technician.
• The technical personnel must have read and understood these Operating Instructions
and must follow the instructions contained therein.
• Faults at the measuring point may only be rectified by authorized and specially trained
personnel.
Repairs not described in the Operating Instructions provided must be carried out only
directly at the manufacturer's site or by the service organization.
2.2 Intended use
The sensor is used to measure turbidity and solids content in water and wastewater.
The sensor is particularly suited for use in the following applications:
• Turbidity measurement in the outlet
• Solids content in activated sludge and recirculation
• Solids content in sludge treatment
• Filterable matter in outlet of WWTPs
Use of the device for any purpose other than that described, poses a threat to the safety of
people and of the entire measuring system and is therefore not permitted.
The manufacturer is not liable for damage caused by improper or non-designated use.
2.3 Workplace safety
As the user, you are responsible for complying with the following safety conditions:
• Installation guidelines
• Local standards and regulations
• Regulations for explosion protection
Electromagnetic compatibility
• The product has been tested for electromagnetic compatibility in accordance with the
applicable international standards for industrial applications.
• The electromagnetic compatibility indicated applies only to a product that has been
connected in accordance with these Operating Instructions.

Turbimax CUS51D Basic safety instructions
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2.4 Operational safety
Before commissioning the entire measuring point:
1. Verify that all connections are correct.
2. Ensure that electrical cables and hose connections are undamaged.
3. Do not operate damaged products, and protect them against unintentional operation.
4. Label damaged products as defective.
During operation:
‣If faults cannot be rectified:
products must be taken out of service and protected against unintentional operation.
2.5 Product safety
The product is designed to meet state-of-the-art safety requirements, has been tested, and
left the factory in a condition in which it is safe to operate. The relevant regulations and
international standards have been observed.

Product description Turbimax CUS51D
8 Endress+Hauser
3 Product description
3.1 Product design
The sensor is designed for continuous in-situ determination of turbidity and solids content.
The sensor with the 40 mm (1.57 in) diameter can be operated directly and completely in
the process without the need for further sampling (in-situ).
The sensor includes all necessary modules:
• Power supply
• Light sources
• Detectors
Detectors detect the measuring signals, digitize them and process them to form a
measured value.
• Sensor microcontroller
This is responsible for controlling internal processes and transmitting data.
All data - including the calibration data - are stored in the sensor. The sensor can be
precalibrated and used at a measuring point, calibrated externally, or used for several
measuring points with different calibrations.
3.1.1 Measuring principle
For turbidity measurement a light beam is directed through the medium and is deflected
from its original direction by optically denser particles, e.g. particles of solid matter. This
process is also called scattering.
1
2
3
4
A0030850
 1 Deflection of light
1 Light source
2 Light beam
3 Particle
4 Scattered light
The incident light is scattered in many directions, i.e. at different angles to the direction of
propagation. 2 angle ranges are of particular interest here:
• Light scattered at a 90° angle is used primarily for turbidity measurement in drinking
water.
• Light scattered at a 135° angle extends the dynamic range for high particle densities.

Turbimax CUS51D Product description
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90°
135°
123
A0030846
 2 Principle mode of operation of turbidity sensor
1 Light source
2 135° light receiver
3 90° light receiver
If the particle density in the medium is low, most of the light is scattered in the 90°channel
and a small amount of light is scattered in the 135° channel. As the particle density
increases, this ratio shifts (more light in the 135° channel, less light in the 90° channel).
1
Ir
FNU
90°
135°
A0030849
 3 Signal distribution as a function of the particle density
Ir Relative intensity
FNU Turbidity unit
The CUS51D turbidity sensor has 2 sensor units, which are independent of each other and
arranged in parallel. The application-dependent evaluation of both signals leads to stable
measured values.

Product description Turbimax CUS51D
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12
3
4
5
6
A0030845
 4 Arrangement of light sources and light receivers
1, 2 Light sources 1 and 2
3, 5 135° light receiver
4, 6 90° light receiver
The sensor covers a broad range of turbidity and solids measurements thanks to the
optical arrangement with 2 light sources, each with 2 light receivers placed at different
angles (90° and 135°).
• As soon as the customer selects an application, e.g. Activated sludge, the optical
method best suited for the particular measuring task is automatically activated in the
sensor (e.g. 90° measurements with both light sources).
• The double sensing system (2 light sources with 2 receivers per source) largely
compensates for measurement errors caused by fouling (4-beam pulsed light method
→  10).
The sensor types available vary in terms of their measuring ranges and therefore the
range of available applications.
3.1.2 Measuring methods
4-beam pulsed light method
The method is based on 2 light sources and 4 light receivers. Long-life LEDs are used as
monochromatic light sources. These LEDs are pulsed alternately and generate 4 scattered
light signals per LED pulse at the receivers.
This offsets interference influences such as extraneous light, LED aging, fouling of
windows and absorption in the medium. Depending on the chosen application, different
scattered light signals are processed. The signal type, number and calculation are stored in
the sensor.

Turbimax CUS51D Product description
Endress+Hauser 11
S1E1-135
E2-135
S2
E1-90
E2-90
A0030847
 5 4-beam pulsed light method
S1 S2Light source
E90 Light receiver for 90° scattered light
E135 Light receiver for 135° scattered light
90° scattered light method
Measurement is performed with a wavelength of 860 nm, as described in ISO 7027/EN
27027.
The emitted light beam is scattered by the solid particles in the medium. The scattered
radiation generated in this way is measured by scattered light receivers, which are
arranged at an angle of 90° to the light sources. The turbidity of the medium is determined
by the amount of scattered light.
S
E
a
P
A0030852
 6 90° scattered light method
S Light source
E Receiver
P Particle
135° backscattered light method
The emitted light beam is scattered by the solid particles in the medium. The
backscattering generated is measured by scattered light receivers, which are arranged next
to the light sources. The turbidity of the medium is determined based on the quantity of
back-scattered light. It is possible to measure very high turbidity values with this type of
scattered light measurement.

Product description Turbimax CUS51D
12 Endress+Hauser
S1
E1P
I0
IS
a
Is= I0· C · A· f(a)
A0030855
 7 Principle of backscattered light method
IoIntensity of transmitted light
IsIntensity of scattered light
A Geometric factor
C Concentration
P Particle
f(α) Angle correlation

Turbimax CUS51D Incoming acceptance and product identification
Endress+Hauser 13
4 Incoming acceptance and product
identification
4.1 Incoming acceptance
1. Verify that the packaging is undamaged.
 Notify the supplier of any damage to the packaging.
Keep the damaged packaging until the issue has been resolved.
2. Verify that the contents are undamaged.
 Notify the supplier of any damage to the delivery contents.
Keep the damaged goods until the issue has been resolved.
3. Check that the delivery is complete and nothing is missing.
 Compare the shipping documents with your order.
4. Pack the product for storage and transportation in such a way that it is protected
against impact and moisture.
 The original packaging offers the best protection.
Make sure to comply with the permitted ambient conditions.
If you have any questions, please contact your supplier or your local Sales Center.
4.2 Product identification
4.2.1 Nameplate
The nameplate provides you with the following information on your device:
• Manufacturer identification
• Order code
• Extended order code
• Serial number
• Safety information and warnings
‣Compare the information on the nameplate with the order.
4.2.2 Identifying the product
Product page
www.endress.com/cus51d
Interpreting the order code
The order code and serial number of your product can be found in the following locations:
• On the nameplate
• In the delivery papers
Obtaining information on the product
1. Go to www.endress.com.
2. Page search (magnifying glass symbol): Enter valid serial number.
3. Search (magnifying glass).
 The product structure is displayed in a popup window.
4. Click the product overview.
 A new window opens. Here you fill information pertaining to your device,
including the product documentation.

Incoming acceptance and product identification Turbimax CUS51D
14 Endress+Hauser
Manufacturer's address
Endress+Hauser Conducta GmbH+Co. KG
Dieselstraße 24
70839 Gerlingen
Germany
4.3 Scope of delivery
The scope of delivery comprises:
• 1 sensor, version as ordered
• 1 x Operating Instructions
‣If you have any queries:
Please contact your supplier or local sales center.
4.4 Certificates and approvals
Current certificates and approvals for the product are available at www.endress.com on the
relevant product page:
1. Select the product using the filters and search field.
2. Open the product page.
3. Select Downloads.

Turbimax CUS51D Mounting
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5 Mounting
5.1 Mounting requirements
5.1.1 Dimensions
Ø 40
(1.57)
NPT ¾“
G1
82.7 (3.26)
188.5 (7.42)
12.5 (0.49)
20.5
(0.81)
13.5 (0.53)
36
(1.42)
A0030853
 8 Dimensions. Engineering unit: mm (in)

Mounting Turbimax CUS51D
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Compressed air cleaning
Ø 40.1 (1.58)
Ø 50 (1.97)
72 (2.83)
77.3 (3.04)
17.8
(0.70)
11.5 (0.45)
65.8 (2.59)
17.8
(0.70)
48 (1.89)
AB
A0030854
 9 Compressed air cleaning. Engineering unit: mm (in)
A Version 6 mm (0.24 in)
B Version 6.35 mm (0.25 in)
5.2 Mounting the sensor
The sensor can be installed with different assemblies or directly in a pipe connection.
However, the CYA112 immersion assembly must be used for continuous operation of the
sensor under water.
5.2.1 Measuring system
A complete measuring system comprises:
• Turbimax CUS51D turbidity sensor
• Liquiline CM44x multi-channel transmitter
• Assembly:
• Flexdip CYA112 assembly and Flexdip CYH112 holder or
• Retractable assembly, e.g. Cleanfit CUA451

Turbimax CUS51D Mounting
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1
2
3
4
5
6
A0051207
 10 Measuring system with immersion assembly (example)
1 Main pipe, Flexdip CYH112 holder
2 Liquiline CM44x multi-channel transmitter
3 Weather protection cover
4 Transverse pipe, Flexdip CYH112 holder
5 Wastewater assembly Flexdip CYA112
6 Turbimax CUS51D turbidity sensor
2
3
5
4
1
A0030856
 11 Measuring system with immersion assembly (example)
1 Liquiline CM44x multi-channel transmitter
2 Weather protection cover
3 Transverse pipe, Flexdip CYH112 holder
4 Wastewater assembly Flexdip CYA112
5 Turbimax CUS51D turbidity sensor

Mounting Turbimax CUS51D
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1
3
4
2
5
A0030843
 12 Measuring system with retractable assembly (example)
1 Turbimax CUS51D turbidity sensor
2 Liquiline CM44x multi-channel transmitter
3 Cleanfit CUA451 retractable assembly
4 Flow direction
5 Optical windows
5.2.2 Installation examples
Pipe installation
a
1
2
A0051206
 13 Installing with retractable assembly
1 Flow direction
2 Optical windows
The installation angle α must not exceed 90° →  13,  18. The recommended
installation angle is 75°. The optical windows of the sensor must be aligned along the flow
direction.
The medium pressure may not exceed 2 bar (29 psi) for manual assembly retraction.

Turbimax CUS51D Mounting
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A0035858
 14 Installing with CYA251 flow assembly
The installation angle is 90°. For turbidity measurements < 200 FNU, the backscattering of
the internal surfaces of the assembly causes distortions in the measured values.
The following diagram shows different installation scenarios in pipes, indicating whether
or not they are permitted.
4
5
2
2
1
3
3
A0030848
 15 Orientations and positions (with CUA451 retractable assembly)
• When using reflective materials (e.g. stainless steel), the pipe diameter must be at least
100 mm (3.9 in). An onsite calibration is recommended.
• Install the sensor in places with consistent flow conditions.
• The best installation location is in the ascending pipe (item 1). Installation is also
possible in the horizontal pipe (item 5).
• Do not install in places where air spaces or bubbles occur (item 3) or where
sedimentation may occur (item 2).
• Avoid installation in the down pipe (item 4).
• When measuring turbidity < 200 FNU, the backscattering of the pipe wall causes
distortions in the measured values. For this reason, measured value adjustment with an
offset is recommended here.
• Avoid fittings downstream from pressure reduction stages which can lead to outgassing.

Mounting Turbimax CUS51D
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Immersion operation
Fixed installation with wastewater assembly
1
2
3
4
A0013383
 16 Installation on railing
1 Turbimax CUS51D turbidity sensor
2 Wastewater assembly Flexdip CYA112
3 Transverse pipe, Flexdip CYH112 holder
4 Main pipe, Flexdip CYH112 holder
1
2
3
4
5
6
A0051207
 17 Installation with upright post
1 Main pipe, Flexdip CYH112 holder
2 Liquiline CM44x multi-channel transmitter
3 Weather protection cover
4 Transverse pipe, Flexdip CYH112 holder
5 Wastewater assembly Flexdip CYA112
6 Turbimax CUS51D turbidity sensor