AF26 VIS/NIR Sensor

Dual Channel VIS/NIR Absorption Sensor

The AF26 is a high precision dual channel color sensor for inline operation; the secondary wavelength is designed to compensate the desired light absorbance measurement from any undesired light scattering influence, such as suspended solids, gas bubbles, immiscible fluids or window fouling. The AF26 sensor’s output can be correlated to almost any color scale including APHA and Hazen.

Used For

  • Color scales:
    • APHA / HAZEN / Pt/Co color
    • AOCS (Method Cc 13b-45) color
    • ASTM (D1500) color
    • EBC color
    • ASBC color
    • Gardner (ASTM D1544) color
    • ICUMSA color
    • KLETT color
    • Reference Base Unit (RBU, color)
    • Saybolt (ASTM D 156, D 6045) color
  • Concentration control of
    • chlorine and chlorine dioxide (gas and liquid)
    • of metal ions (Iron, Chromium, Copper, Nickel, Cobalt, Manganese, etc. ) in Plating industry
  • Drinking water treatment (APHA color)
  • Colored waste water monitoring (e.g., Textile industry)
Features
Benefits

Configurable dual channel color sensor with 2 wavelengths
Flexibility to measure a broad range of products for turbidity compensated color measurement

High performance sensor for broad range of applications
Measurement can be expressed in any color scale, e.g., APHA, Saybolt, ASTM, ICUMSA, EBC, Gardner etc.

Available for installations in hazardous areas
Complies with IECEx, ATEX, FM

NIST-traceable validation accessories
Easy on-site / on-demand verification

Different wavelength modules available
Application optimized configuration

The AF26 is a high precision dual channel sensor which is designed for inline operation. The dual channel AF26 sensor provides accurate absorption measurements with remarkable repeatability, linearity and resolution. The AF26 sensor’s output can be correlated to almost any color scale including APHA and Hazen. Selected combinations of optical filters make it possible to focus on specific wavelengths ensuring suitable adaptation to the application. Typically, one of the two measured wavelengths is used as a reference channel, where it can be used to prevent the influence of particulate, gas bubbles and lamp aging. Additionally, NIST-traceable calibration accessories provide absolute measurement confidence.

AF26
Schematic
  1. Sensor Body
  2. Windows
  3. Beam splitter
  4. Filter A
  5. Measurement detector A
  6. Filter B
  7. Measurement detector B
  8. Optics module
  9. Lamp module
Measurement
Measurement principle

2- Channel Absorption of light

Measurement wavelength(s)

385/430, 385/550, 385/620, 400/550, 400/620, 420/700, 430/525, 430/620, 430/700, 460/620, 470/620, 470/700, 525/620, 525/700, 550/800, 620/800, 660/750, 670/550, 670/750, 1000/800 nm, others on request

Detector(s)

2 silicon photodiodes (hermetically sealed)

Measuring Range

any measuring range between

0 - 0.05 to 3 CU

(dependent on filter used)

(contact product specialist for application specific ranges)

Optical path length

1 - 1000 mm

Calibration

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)

Resolution

< ± 0.05 % of respective measuring range

Repeatability

< ± 0.5 % of respective measuring range

Linearity

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

Protection

all optical parts have an IP rating of IP65 or higher

Sensor Body
Material

Stainless steel 1.4435 (SS 316L), 1.4539, 1.4571 (SS 316Ti), 1.4462, Titanium 3.7035 (Grade 2), Hastelloy 2.4602 (C22), Plastic TFM4215, PVC, ... others on request

Line size

1/8 in. to 6 in. (DN 6 to DN 150), ... others on request

Process connection

Flanges (ASME, DIN, JIS), Clamps (TC, ISO, DIN), Female Threads (NPT, DIN), Sanitary Threads (DIN 11851), Tube Ends (DIN, ISO, OD), Varivent, ... others on request

Process pressure

10 mbar to 100 bar (0.15 psi to 1450 psi) - higher on request depending on process connection, materials and design

Windows

1-Pyrex®, 2-Sapphire, 3-Sapphire Biotech

Window gaskets

Silicone (FDA), Viton® (FDA), EPDM (FDA / USP Class VI), Kalrez® 4079, ... others on request

Temperature Ratings
Process temperature

permanent: 0 - 120 °C ( 32 - 248 °F)

peak 15 min/day: 0 - 150 °C ( 32 - 302 °F)

Process temperature
OPTION HT

permanent: -30 - 240 °C (-22 - 464 °F)

peak 15 min/day: -30 - 260 °C (-22 - 500 °F)

Process temperature
OPTION EX

permanent: -30 - 120 °C (-22 - 248 °F)

peak 15 min/day: -30 - 150 °C (-22 - 302 °F)

Process temperature
OPTION EX-HT

permanent: -30 - 240 °C (-22 - 464 °F)

peak 15 min/day: -30 - 260 °C (-22 - 500 °F)

Ambient temperature

permanent: 0 - 40 °C ( 32 - 104 °F)

operation: -30 - 40 °C (-22 - 104 °F) with options HT / EX / EX-HT

transport: -20 - 70 °C ( -4 - 158 °F)

Explosion Proof
Ex-proof

none

Ex-proof
OPTION EX (EN-D)

Sensor assembly in ex-proof version accor. ATEX (EN-D)

Ex-proof
OPTION EX (FM-D)

Sensor assembly in ex-proof version accor. FM (FM-D)

Calibration
Calibration adapter

none

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.

Product Variants

AF26-EX-HT-VB
AF26-EX-HT-VB
AF26-EX-VB
AF26-EX-VB
AF26-VB-PV
AF26-VB-PV

Process temperature OPTION HT

permanent: -30 - 240 °C (-22 - 464 °F)
peak 15 min/day: -30 - 260 °C (-22 - 500 °F)

Ex-proof OPTION EX (EN-D)

Sensor assembly in ex-proof version accor. ATEX (EN-D)

Ex-proof OPTION EX (FM-D)

Sensor assembly in ex-proof version accor. FM (FM-D)

C4000 - C8000 Product Information

Visit our documentation page to view a complete list of translated documents.