A5S1 Differential-Hall-Effect Speed Sensor Ex ia and Ex nA. A5S1DD0, A5S1DS0, A5S1DD3, A5S1DS3, A5S1DD4, A5S1DS4, A5S1DD0-n, A5S1DS0-n, A5S1DD3-n, A5S1DS3-n, A5S1DD4-n, A5S1DS4-n.


Sensor A5S1DS3 for detection of rotational speed and direction of rotation in Hazardous Areas Zone 0 or 1 and highest safety requirements up to SIL3

The BRAUN Speed Sensors Series A5S1 are TÜV certified for SIL3 acc. IEC 61508:2010 and therefore meet the high SIL3 standards. To meet the specific requirements of hazardous areas (Ex Zone 0 or 1) we provide these specialized types which are certified for ATEX/IECEx, as well as for other international standards such as UL/CSA and EAC (Russia, Kazakhstan, and the Belarus Customs Union). A5S1 sensors in conjunction with our Isolating Barrier D461 provide an intrinsically safe implementation to meet these specific requirements.

The correct choice of sensor is always a prerequisite to achieving a successful solution. Therefore BRAUN A5S1 sensors base on the proven Differential-Hall-Effect principle. Their low end of 0 Hz allows monitoring the machine down to zero speed. They are contact-free, wear-free, maintenance-free and unsusceptible versus external magnetic stray fields and machine vibration. These characteristics make the series of A5S1 sensors especially suited for all applications where high levels of accuracy and reliability are at a premium.
In contrast, other sensors like magnet-inductive or static Hall-sensors do not meet these demands.

Each sensor in the series is available in various lengths and diameters and comes with a choice of connections. However, functionally all sensors have the same characteristics.
The stainless steel sensor housing is sealed at the front and is pressure resistant (>200bar). A flat shaft is available or with a screw-in thread M12x1, M14x1, M14x1,5, M16x1, M16x1,5, M18x1, M18x1,5, M22x1, 5/8-18UNF-2A. Customized dimensions and thread specifications are possible.

Key Features

  • SIL3/IEC 61508:2010 certified by TÜV
  • Detection of rotational speed and direction of rotation in Hazardous Areas Zone 0 or 1
  • Speed range from 0 Hz to 12 kHz
  • Dual Channel,
    1 track = rotational speed as frequency, 1 track = F/R status as binary signal
  • Air gap to the target/pole wheel up to 2.5 mm (depending on the profile size)
  • Temperature range -40…+125 °C (-40…+255 °F)
  • Differential principle diminishes the influence of external magnetic stray fields and machine vibration
  • Sealed stainless steel enclosure > 200 bar pressure to sensor tip
  • Available for connection via tight plug, or with firmly attached cable (PVC or Teflon® insulated)
  • Powerful square wave output signal equally high over the entire speed range
  • Sensor short circuit proof and protected versus polarity error
  • Accepting fine and coarse profiles, as gear wheels, slots, cams, holes in any ferrous material
  • Requires Isolating Barrier D461
  • For installation in hazardous areas as intrinsically safe operating resource
    • ATEX/IECEx certified for Ex ia IIC T4/T6 Ga
    • UL/CSA certified for Class I, Div 1, Groups A, B, C, D
    • EAC certified for Ex ia IIC T4/T6 Ga


  • Contact-free with a large air gap, so the potential for damage is eliminated
  • Wear-free due to its unique design principle
  • Maintenance-free during Lifetime, therefore minimized TCO
  • Unsusceptible versus external magnetic stray fields and machine vibration
  • Operates down to zero speed
  • Can not be damaged by faulty wiring
  • Almost every target profile can be used
  • A5S1 sensors do not influence each other, no mounting distance in between is required

Product Brochures

Title Language File type
A5S Overview Brochure English PDF
A5S1DS3 Product Brochure English PDF

Technical Manuals

Title Language File type
A5S1DS3 Manual English PDF
A5S1DS3 Manual PDF

Product Certificates & Declarations of Conformity

Document type Language Scope File type
EU Declaration of Conformity English European Union PDF
SIL3 Certificate English Worldwide PDF
SIL3 Certificate Worldwide PDF
ATEX EU Type Examination Certificate English European Union (ATEX) PDF
IECEx Certificate of Conformity English International (IECEx) PDF
UL/CSA Approval English USA/Canada PDF
EAC Clearance Certificate Eurasian Customs Union (EAC) PDF
EAC Ex TR CU Certificate Eurasian Customs Union (EAC) PDF
Metrology Certificate A5S Eurasian Customs Union (EAC) PDF
Metrology Certificate A5S+E16 Eurasian Customs Union (EAC) PDF