AS16-N Turbidity Probe

Single Channel Turbidity Probe

High precision probe for direct installation into pipelines and vessels measuring NIR light absorption (turbidity) of various liquid samples. The optical path length can be individually configured to meet the process control requirements with the highest accuracy.

Used For

  • Absorbance Scale:
    • CU (concentration units)
  • Turbidity based
    • phase separation control (beer / milk, milk / water)
    • inlet separator control
    • cell density in fermentation (OD, AU, TCD, CC, WCW, DCW)

Inline turbidity measurement in demanding process conditions
No sampling or by-pass installation needed

Fast and accurate turbidity measurements
Immediate detection of turbidity changes to verify product quality

Hygienic probe design (3A)
For pipe and vessel installation

Two sensor lengths available (35 mm & 135 mm plus OPL)
Flexibility to mount in a broad range of vessel sizes

Validation accessories
Easy on-site / on-demand verification

The AS16-N is a precision absorption probe, which is designed for direct installation into pipelines and vessels and provides accurate concentration measurements with remarkable repeatability, linearity and resolution. A wide selection of different optical path lengths and insertion depths combined with optional calibration filters and electro-polished stainless steel housing meet all requirements of the biotechnology industry.

The AS16-N uses light from 730-970 nm to measure solids concentration independent from color or color changes.

  1. OPL
  2. Windows
  3. Lamp module
  4. Optics modules (incl. filter)
  5. Detector module

No window gaskets used

Measurement principle

1- Channel Absorption of light

Measurement wavelength(s)

AS16-N:730 - 970 nm


1 silicon photodiode (hermetically sealed)

Measuring Range


any measuring range between

0 - 0.05 to 6 CU

Optical path length

1, 5, 10, 20 or 40 mm


CU (concentration units) application specific calibration

Light source

special incandescent tungsten lamp 5.0 V DC, 970 mA

typical life span: 3 to 5 years (25,000 to 40,000 hours)


< ± 0.05 % of respective measuring range


< ± 0.5 % of respective measuring range


< ± 1 % of respective measuring range (specific to application)


all optical parts have an IP rating of IP65 or higher

Process Adaption

wetted parts: stainless steel 1.4435 (SS 316 L) dF < 1 %, BN2

surface: electro-polished Ra < 0,4 μm

housing: stainless steel 1.4571 (SS 316 Ti)

Port connection

thread G1-1/4 in., ISO 228/1 for port AS25 (similar Ingold-port)

diameter: 25 mm ( D= 25 H7)

O-ring groove for 30 mm and for 60 mm port length

Port gasket

O-ring 18.64 x 3.53 mm EPDM (FDA / USP Class VI)

Insertion depth

35 mm (1.38 in.) + OPL at a port length of 60 mm (2.36 in.)

135 mm (5.31 in.) + OPL at a port length of 60 mm (2.36 in.)

Process pressure

10 mbar to 20 bar (0.15 psi to 290 psi)


Sapphire (seal-less)

Installation accessories
  • weld-in ports
  • Varivent adapter (50.00)
  • clamp adapter (1.5 and 2.0 in.)
Temperature Ratings
Process temperature

permanent:0 - 100 °C (32 - 212 °F)

peak 60 min/day:0 - 150 °C (32 - 302 °F)

Ambient temperature

operation:0 - 40 °C (32 - 104 °F)

transport:-20 - 70 °C ( -4 - 158 °F)

Calibration adapter


Calibration adapter VB

Filter adapter FH03 for calibration filter used for sensor verification

Pressure and temperature ratings specified herein may be subject to limitations - see instruction manual. The appropriate choice of material for all wetted parts is the sole responsibility of the user. Data given are subject to changes without prior notice.

C4000 - C8000 Product Information

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