Hengesbach Turbidity Sensor TURBIMESS NG

TURBIMESS NG is an optical sensor measuring the reflected radiation arising from particles or fat droplets in liquid media. The operating and display elements are housed inside the device head. In addition to a 4-figure, 7-segment display, the device head features two LEDs and three push-buttons.

Status indicators for switching points

The device features two switching points. The operating status of each switching point is indicated by an LED. If a
switching point is activated, the supply voltage can be measured at the corresponding connection of the M12 plug connector (PNP action). At the same time, the corresponding LED also lights up. If the switching point is not activated, the LED does not light up and there is therefore no voltage to be measured at the corresponding switching point’s output.


  • Turbidity sensor with 2-wire 4….20 mA output
  • Process connections Clamp; Varivent; DIN 11851
  • 2 individual programmable switch-points with status LEDs
  • Integrated LED display
  • Easy parametrizing with three push buttons
  • Compact hygienic design made in stainless steel
  • 2 operating modes:
    - NTU mode (linear) for turbidities between 0 and 4.000 NTU
    - 9 select able support points for fat contents up to 30%
  • Temperature resistant long-term: 125°C /short-term 150°C


  • detection of product change
    (e.g. milk – cream – whey)
  • continuous monitoring of e.g. milk fat content / quality inspection
  • monitoring of the cleaning agents’ pollution degree during CIP
  • detection of filter breakdown
  • detection of yeast and cloudy fruit juice


General details

Device typeTURBIMESS NG 
Measuring principleBackscatter from transmitted emitted infra-red light beam 


Measuring rangesFactory setting: Linearised turbidity > 50 to 4000 NTU* 
 9 freely configurable reference points 
 *Configuration using NTU Standard, measurement procedure approximated 
Maximum process pressurePN16 


Output signal4…20mA, 2-wire 
Signal range3.8...20.5mA as per Namur NE043 
Fault signal22mA 
Switched output2x PNP, each of max. 50mA 
 Factory setting: Not activated 

Measuring accuracy

Accuracy± ≤ 0.2% from measuring range end value 
Reproducibility± ≤ 0.1% from measuring range end value 
Thermal influence± ≤ 0.2% / K from measuring range end value 
Setting time after input leap≤ 3s 
Activation time< 2s (The device will carry out a self-test.) 

Conditions of use

Installation position / calibration positionOptimal installation position is in risers (ascending pipes) or, if not possible, to the side of other pipes (to 
 avoid product residues and incorrect measurements due to gas bubbles); device must not be installed in 
 downpipes (descending pipes). 
Medium temperature0...125°C / up to 150°C for brief periods (max. 30 mins) 
Ambient/storage temperature-10...85°C 
Protection class acc. to EN60529IP 67 
Electromagnetic compatibilityacc. to DIN EN 61000 and DIN EN 61326-1 


Electrical connectionRound plug-in connector M12x1, 5-pin, nickel-plated brass (stainless steel available on request) 
Process connection- Clamp connection acc. to DIN 32676, DN50/2" 
 - Varivent flange Type F (d50) and Type N (d68) 
 - Conical couplings with groove union nuts acc. to DIN 11851, DN50 and DN65 
 ˃˃ Scope of delivery not incl. seals and, where applicable, clamps 
Materials- Field housing / lid:Stainless steel 1.4301 (AISI 304)
 - Inspection gauge in lid:Polycarbonate (PC)
 - Housing seal:FPM (Viton®)
 - Process connection / connection adapter:Stainless steel 1.4404 (AISI 316L)
 - Medium-contacting density gauge:Sapphire glass
 - Seal on gauge:Silicone rubber, approved by FDA
Weightapprox. 1.5kg 
Display and operation  
Display4-figure, 7-segment display, incl. decimal point, 2x status LED for switching points 
Operation3 input keys 
Auxiliary energy resources  
Power supply / burden24...30V DC, max. burden: 600 Ω 
CertificatesEG Declaration of Conformity 
 Conformity acc. to Regulation (EC) 1935/2004 
 Acceptance test certificate 2.2 in acc. with EN 10204 for parts which come into contact products 

Download Data Sheet: Turbidity Sensor TURBIMESS NG

Ref: hengesbach.com