McNab Model AP-VISF Scatter Transmitter

Print Version

Special Features

  • Reduced cost
  • Easy installation, no Indicator/Controller (I/C) panel
  • Second cabinet not required for water-proofing
  • Available in proven sanitary (non-o ring) design
  • Air purge or air driers for moisture control in optics
  • 12° to 20° angle forward scatter
  • Relative humidity (RH) indicator to alert potential window fogging
  • 10 times illumination of LED
  • Avoids lamp aging resistance drift
  • Avoids field inter-connecting cable calibration
  • Automatic correction of lamp darkening


The Model AP-VIFS Scatter Transmitter is a compact sensor with integrated electronics. It measures the amount of light received by the photoelectric scanner from the light scatter of suspended particles. It continuously monitors suspended solids interface by measuring the amount of light scatter in the process pipe. The optical cell “no o-ring” sealing meets sanitary requirements as set forth by EHEDG.

Model AP-VIFS provides immediate center-of-the-pipe measurement at full pressure and temperature, eliminating the delay of off-line sampling. The information is transmitted to the customer computer or process controller using a 4-20 mA analog signal. Internal relays are available to open or close valves when designated concentration levels are reached.

Installation involves mounting optical ferrules on a vertical run of pipe (with upward flow) where the process measurement is needed. Visual inspection of the sample chamber can be done at any time during operation by removing the photo sensor head from the optical cell and looking through the optical cell like a sight glass.


Material of Construction Stainless steel, ASTN 316L/DIN 4435
Seals Ethylene propylene (EPDM), Kalrez, etc.
Protective Enclosure NEMA 6 (submersible), IP68
Mounting Sanitary flange, 2 inch Tri-clamp, or McNab standard
Operating Temperature 15 to 225° F (-10 to 115° C)
Operating Pressure 150 psig, 10 bar
Power Requirements 117 or 220 VAC, 50/60Hz, 50 watts (max.)
Standard Output 0-10 Volt DC
Optional Outputs

4-20 mA Ground Isolated, internal or user supplied Excitation Voltage. (Up to 30 volts maximum)


2 SPST closures, 115/230 VAC (only), 0.10 Amp max, or

1 SPDT, 115/230 VAC/VDC, 5 Amp electro-mechanical

Sensitivity Adjusted per application
Weight 20 lbs (9.1 kg.) max

383-2 East 29th Street | Buena Vista, VA | USA 24416-1293

540.261.1045 voice | 540.261.1268 fax |

Copyright © 1999 - 2010  McNab, Inc. All Rights Reserved.  Last modified: 08.12.2010

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