Technical Information

Turbimax W CUS65
Turbidity and solids content sensor
Installation and immersion sensor for low, medium and highconcentrations using the four-beam pulsed light method

Application

Your benefits

The Turbimax W CUS65 sensor is used for optical turbidity andsolids content measurement. Due to various sensor heads thesensor is suitable for use from low to high concentration ranges.

• Four-beam pulsed light method for compensation of sensor
soiling and wearing of optical components• Sensor body made of stainless steel• No mechanically moving parts, therefore no sensor blocking• Measured value processing in sensor resulting in low signaltransmission sensitivity• Aeration systems do not affect measurement• Plug system for quick commissioning• Wastewater clarification / sludge treatment• Boiler feedwater monitoring• Condensate monitoring• Service water monitoring

TI370C/07/en/01.08
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Turbimax W CUS65

Function and system design
Measuring principle

Turbidity measurement
For turbidity measurement a light beam is sent through the medium and is diverted from its original direction
by optically denser particles, e.g. solid matter particles.
Four-beam pulsed light method
The method is based on two light sources and two photo receivers. Long-life LEDs are used as monochromatic
light sources. To eliminate interference from extraneous light sources, these LEDs are pulsed at a rate of severalkHz.
Two measuring signals are detected at the two photo receivers. The four measuring signals are processed in
the sensor and are converted into proportional frequencies. The transmitter assigns the frequencies to theappropriate turbidity units and solids concentrations.
The four-beam pulsed light method compensates the sensor soiling as well as the wearing of the opticalcomponents.
S = Light source
E = Light receiver
S1E1

S2

E2

a0008973

Four-beam pulsed light method

Measuring methods

Depending on the version, the sensor uses the absorption light method (CUS65-A, -B, -C) or the scattered lightmethod (CUS65-D, -E).
Absorption light method
The measuring principle is based on the Lambert-Beer law. The turbidity of the medium is determined by theweakening of the light beam.
The sensor LEDs send a directed light beam to the light receivers. The light beam intensity is weakened by thesolid matter particles in the medium.

IT = I0 · e–ECD

I0 = Intensity of transmitted light
IA = Intensity of absorbed light
IT = Intensity of light transmitted
IS = Intensity of scattered light
E = Extinction coefficient
C = Concentration
D = Optical path lengthI® lg –0 = ECDITIAITI0IS
Da0008974

Absorption light method

90° NIR scattered light method
The measurement uses the 90° scattered light method acc. to ISO 7027 / EN 27027.
The turbidity of the medium is determined by the amount of scattered light. The transmitted light beam witha wavelength in the near-infrared range is scattered by the solid matter particles in the medium. The scatteredbeams are detected by scattered light receivers which are arranged at an angle of 90 ° to the infrared lightsources.

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I0 = Intensity of transmitted light
IS = Intensity of scattered light
A = Geometrical factor
C = Concentration
P = Particle
f(α) = Angle correlation

Is = I0 · C · A · f(a)E2

E1ISISaP a

I0
I0

S2

S1a0008975

90° scattered light method

Backscattered light method
The measurement uses the backscattered light method.
The turbidity of the medium is determined by the amount of backscattered light. The transmitted light beamis scattered by the solid matter particles in the medium. The backscattered beams are detected by scattered
light receivers, which are arranged next to the light sources.
I0 = Intensity of transmitted light
IS = Intensity of scattered light
A = Geometrical factor
C = Concentration
P = Particle
f(α) = Angle correlation

Is = I0 · C · A · f(a)

ISE1

aI0

IS
I0S1Paa0008976

Backscattered light method

I = Intensity of transmitted light
C = Concentration
P = Reversal point
Cal = Calibration range

IP

0.8%

Cal

10%

Ca0008980!

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Note!
CUS65-E has a reversal point at approx. 0.8% of solid matter (as dry substance) and can thus not be calibrated
with water. Therefore only use the sensor starting from a concentration >10 g/l.

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Measuring system

A complete measuring system comprises:• Turbidity transmitter CUM740• Turbidity sensor Turbimax W CUS65• Immersion pipe CYY105 or• Retractable assembly Cleanfit CUA451• Extension cable (optional)• Junction box (optional)

23141243a0008988

a0008989

Measuring system with immersion pipe

Measuring system with retractable assembly

1
234

1234

Turbidity sensor Turbimax W CUS65-C
Immersion pipe CYY105
Turbidity transmitter CUM740
Basin or channel

Turbidity sensor Turbimax W CUS65-A
Turbidity transmitter CUM740
Retractable assembly Cleanfit CUA451
PipeInput
Measured variable

Measuring rangeTurbidity
Solids content
VersionMeasuring range

Application

CUS65-A
CUS65-B
CUS65-C
CUS65-D
CUS65-E

0 to 12 g/l
0 to 40 g/l
0 to 50 g/l
1 to 1000 FNU
10 to 150 g/l

Activated sludge, centrate
Return sludge
Primary sludge, digested sludge
Wastewater outlet, service water, condensate, boiler feedwater
Centrifuge inlet, press inlet

Power supply
Electrical connection

Connect the sensor directly to the transmitter by using the special measuring cable with SXP plug.

a0004118

SXP plug

Cable specification

4Cable length

Cable cross section

up to 50 m (160 ft):
up to 100 m (330 ft):
up to 200 m (660 ft):

5 x 0.35 mm2 (i 22 AWG)
5 x 0.5 mm2 (i 21 AWG)
5 x 1.0 mm2 (i 18 AWG)

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Turbimax W CUS65

Performance characteristics
Maximum measured error< 1% of measuring range end(system measured error related to the primary formazine standard / tracing according to ISO 5725 and ISO
7027 / EN 27027)

Wave length

880 nmReference measurement

by four-beam pulsed light method

Factory calibration

CUS65-A, -B, -C, -E:
CUS65-D:

SiO2Formazine acc. to ISO 7027 / EN 27027

Installation
Installation instructions!

Installation options:• with retractable assembly CUA451• with immersion pipe CYY105
Note!
• Observe the required mounting clearance for the installation mode selected. Installing the sensor in pipes orclose to a wall can lead to backscattering resulting in signal increase, mainly with measurements in low
turbidity ranges (<100 FNU).
• Make sure the sensor is completey immersed at changing water levels.
Installation angle α dependent on sensor version:• CUS65-A: 80°• CUS65-B: 90°• CUS65-C, E: 100°• CUS65-D: 110°1aa0008990

Installation with retractable assembly
Arrow = flow direction of the medium

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min. 200 (8)90°45°a0008991

Immersion pipe angles

min. 100 (4)Arrow = flow direction of the medium

mm (inch)a0008992

Wall distance with immersion pipe

• CUS65-A: 45 °• CUS65-D: 90 °• CUS65-B, -C, -E: 180 ° (straight)

Environment
Ambient temperature range-20 to 60 °C (0 to 140 °F)

Storage temperature-20 to 60 °C (0 to 140 °F)

Humidity

5 to 95 %Ingress protection

IP 68

Process
Temperature pressure
diagram°F
40506070907710411012213087

680
57060

4bar50 psi
340

230

1201510202530

405060°C
a0008127

Temperature pressure diagram

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Turbimax W CUS65

Process temperature range

0 to 50 °C (32 to 120 °F)

Process pressure

1 to 6 bar (15 to 87 psi)

Minimum flow

No minimum flow required.
Make sure that there is a sufficient turbulence for solids with a tendency to sedimentation.

Mechanical construction

ACB

D

142 (5.59)

154 (6.06)

Ø40(1.57)

154 (6.06)

G1147 (5.79)

NPT ¾

145 (5.71)

60 (2.36)

Design, dimensions

Emm (inch)
a0008995

Dimensions dependend on the sensor version (see ordering information)

AB

CD

E
a0008996

Sensor versions

Weightapprox. 1 kg (2.2 lbs)

Materials

SensorOptical windows
O-rings

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Stainless steel 1.4404 (AISI 316L)
CUS65-A, -C, -E: Epoxy resin
CUS65-B, -D: Polyoxymethylene (POM)
Viton®

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Turbimax W CUS65

Ordering information
Product structure TurbiMax W
CUS 65

Measuring range, application
A 0 to 12 g/l, activated sludge, centrate
B 0 to 40 g/l, return sludge
C 0 to 50 g/l, primary sludge, digested sludge
D 1 to 1000 FNU, wastewater effluent, service water, condensate, boiler feedwater
E 10 to 150 g/l, centrifuge inlet, press inlet
Certificates
1 Factory calibration certificate
Process connection
A G1 + NPT 3/4 thread
Y Special version acc. to customer specification
Connecting cable
1 7 m (23 ft), SXP plug
2 15 m (49 ft), SXP plug
3 1 m (3.3 ft) + extension cable 10 m (32 ft), both with SXP plugSealA Viton
Y Special version acc. to customer specification
CUS65-

Scope of delivery

8complete order code

The scope of delivery comprises:• 1 CUS65 sensor, cable length depending on version• 1 extension cable (only version CUS65-xxx3)• 1 Quality certificate• 1 Operating Instructions BA370C/07/en

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Accessories
Assemblies

Retractable assembly Cleanfit CUA451• retractable assembly with ball valve; for turbidity sensors; material: stainless steel• ordering acc. to product structure (Technical Information TI369C/07/en)Immersion assembly CYY105• for sensor immersion in basins, SS 1.4404 (AISI 316L) pipe, SS 1.4571 (AISI 316Ti) fitting• Ordering acc. to product structure (Technical Information TI092C/07/en)

Wall mounting

Wall attachment for immersion pipes• Material: stainless steel 1.4301 (AISI 304)
• order no. 51503581
Counter plate• Material: stainless steel 1.4301 (AISI 304)
• order no. 51512992

5 )R1 .59(0mm (inch)

160 (6.3)
130 (5.1)

mm (inch)a0008997

Wall mounting

4 (0.16)130 (5.1)

160 (6.3)

300 (11.8)

130 (5.1)

11 (0.43)

130 (5.1)

Æ11)(0.43a0008998

Counter plateTransmitters

CUM740• Transmitter for turbidity and solids content measurement• see Technical Information (TI232C/07/en)

Connection accessories

Extension cable• Extension cable length 10m (32 ft)• Shielded, with SXP plug and SXK coupling• Ingress protection IP 67• Order No.: 51503633
Plugs• SXP plug
– 7-pole– Order No.: 51504027• SXK coupling– 7-pole– Order No.: 51504025
Junction box• Junction box for extension of cable connection between sensor and instrument• Sensor cable input SXB socket, cable output Pg 11 cable gland• Material: Makrolon®
• Ingress protection IP 67• Order No.: 51503632

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Instruments International
Endress+Hauser
Instruments International AG
Kaegenstrasse 24153 Reinach
Switzerland
Tel.+41 61 715 81 00
Fax+41 61 715 25 00
www.endress.com
info@ii.endress.com

TI370C/07/en/01.08
71067562
Printed in Germany / FM+SGML 6.0 / DT