Proxistor part numbers are logical in English, a selection chart is available in pdf format or you can read about it. for chart click

The first letter of the part number: indicates sensor type e.g.
  • "C" is for Capacitive
  • "I" for Inductive
  • "U" for Ultrasonic
  • Photoelectrics, you need to know a little more about photocells because there are different ways of using light for sensing, here the part numbers start:
    • "D" for diffuse photoelectric
    • "R" for Retro reflective (working with a reflector)
    • "T" for through-beam where two units are used and the light beam is emitted from one and received by another.
The second letter of the part number: indicates electrical type:
  • "A" is for AC (this means 2 wire except in the case of some photoelectrics
  • "P" is for pnp, a DC 3 wire system (also known as switching positive or negative earth)
  • "N" is for npn, also a DC 3 wire system (also known as switching negative or positive earth)
  • "U" is for universal, a unit which can be used as AC or DC (this would usually be 2 wire in AC or DC mode)
  • "D" indicating DC where a unit can be used as 3 wire pnp or npn type or perhaps 2 wire DC only (check the details in the datasheet to be sure of what you are buying).
The third letter of the part number: indicates the output state of the sensor.
  • "O" for normally open
  • "C" for normally closed
  • "U" if the output state is user selectable
    • Note: the normal state for proximity switches is understood to mean the "no target present" state. Therefore when a target is detected by a normally open sensor the output is made. Using mechanical limit switch terminology this would be known as a "making" output, in German a "Schleisser" (cutter) output. Normally closed would be a "breaking" output, in German "offner" or opening.
The next section of the part number: indicates the nominal sensing range:

The unit of measure, unless otherwise specified, is metric, mm.
(Note: One Inch = 25.4mm or 2.54cm)

  • Nominal range (Sn) is a good indication of the range you might expect to achieve in your application but only an indication.
  • The actual sensing range you can achieve in your application will (depending on the sensor type used) be affected by target material, target size, target colour, i.e.: the ability of the target to reflect sound or light waves (in the case of ultrasonic and or optical sensors).

For 1mm to 999mm we display three places, therefore:

  • 40mm nominal range looks like 040 in our part number
  • 8mm looks like 008
  • 4mm looks like 004

What about fractions of a millimetre?

  • we add a place but the first places will be zeros.
    • 2.5mm looks like 0025 (so 1.5mm would be 0015)

What about sensors with long ranges?

  • TPO10000VCSF is a photoelectric with a 10 Metre range.
    • that is 10,000mm i.e. 1,000cm or 10m.
    • To recap, the TPO.... "T"=Through-beam, "P"=pnp,
      "O"=normally open. After the nominal range "V" means Variable.

What about sensors with adjustable or variable ranges?

  • 010V indicates 10mm, the V indicates Variable, the setpoint or sensitivity is adjustable / variable, usually by a potentiometer.
  • Nominal range does also not always indicate maximum, the capacitive sensor CPO040VFSN for example (which you know from the explanation above is a C = Capacitive P = pnp O = normally open with a nominal range of 040V = 40mm (variable / adjustable) can in many conditions and depending on the target achieve a range of 100mm. For capacitive sensors "nominal range" is the range at which the sensors were tested and to which the sensor is set at the factory.
  • the TPO10000VCSF photoelectric through-beam mentioned above, whose nominal range is 10m has been measured at up to 20m.
What if I cannot find the range I want?
  • Ask us,
    • Nominal range does also not always indicate maximum.

      The capacitive sensor CPO040VFSN for example (which you know from the explanation sheet so far is "C"=capacitive, "P"=pnp, "O"=normally open with a nominal range of "040V"=40mm (variable) can in some situations with some targets achieve 100mm.
      Nominal range for capacitive sensors is a safe range, to which the sensors were tested and to which they are set at the factory.


      The TPO10000VCSF photoelectric through-beam mentioned above, whose nominal range is 10m has been measured at up to 20m.

    • it may be possible to solve your application with a different technology or at the expense of a variable which may not be critical to your application.

      For example working above nominal range may be possible and it may result in one or more of the following; weaker temperature compensation, increased hysteresis or changes in EMI susceptibility levels at various frequencies. Such things may not be critical in your application.

      For better understanding of what range is achievable for your application please do read the installation and setting up notes for the sensor type you are interested in and have an idea of the target you wish to detect.

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After the section of the part number on nominal range are three letters that denote the housing size and type, the first

Housing size:

  • "A"= M8
  • "B"= M12
  • "C" = M18 (Metric 18x1mm thread)
  • "D" = M30 (Metric 30x1.5mm thread)
  • "E" = 20mm smooth body
  • "F" = 34mm smooth body
  • "G" = Rectangular 40 x 26 x 12mm
  • "H" = M5
  • "K" = 4mm diameter
  • "L" = 3mm diameter
  • etc...
Housing material and style (if a factory fitted cable or connector)
  • "S" = plastic (GRP) body with cable
  • "T" = plastic (GRP) body with connector
  • "D" = stainless steel body with cable
  • "E" = stainless steel body with connector
  • "M" = plated brass body with cable
  • "N" = plated brass body with connector
  • etc..
The next and last standard part number letter: if the sensor is F = flush fitting (also known as embedable) or N = non flush

That is the last of the standard lettering system:
After these we sometimes use appendix letters for special applications for example
Photoelectric through beams sold as separate units E = emitter R = receiver on one unit H = high speed switching, this unit can switch at 10,000 Hz!

For the full information click to see the pdf file.


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