Got a Question About Sensors or Connectivity? Ask the Experts!

Normally the sensor experts here at SensorTech blog chose topics that we think will interest our readers.  But this week we’re asking our readers to send us their top questions about sensors and connectivity.  Got a question about how sensors work?  How to select them?  How to hook them up to a network?  How to properly install and set them up?  Some nagging problem with an application that’s driving you crazy?  We’d like to hear from you!

Please enter your question (or questions) in the comment box below.  We’re looking forward to doing our best to help you out!

15 Replies to “Got a Question About Sensors or Connectivity? Ask the Experts!”

  1. Osama Aref says:

    I’m working on a project where I’m using a drone to detect high CO2 concentrations. Is there a gas sensor with a reasonable price that can detect CO2 from a distance? The distance between the sensor and the gas may be around 20 meters. Thank you.

    1. Henry Menke says:

      Thanks for your question, Osama. Our expertise is mainly limited to sensors that detect the presence or position of objects in an automation context. You are looking for a more specialized type of atmospheric gas detector. I am aware of home CO2 detectors that plug into wall power but I don’t know if that technology is adaptable to DC power for a mobile application or not.

    1. Thanks for your question. Although we have applied some specialized sensors in medical equipment for detecting fluid levels, transcutaneous or transdermal sensing of CO2 levels in the body falls outside our area of application expertise. We specialize primarily in the industrial sensing arena. We would recommend searching on transdermal or transcutaneous sensing to locate some scholarly research on this interesting topic.

  2. SAMPATH D.Y.K. says:

    What are the best sensor to use to detect obstacles and may be to classify the obstacles like by shape or other attributes??

    1. Hello,

      Thank you for your question. Balluff Ultrasonic sensors could be a great consideration for your application as they offer many features and benefits. Our Ultrasonic product line can detect obstacles with many different shapes without false triggered outputs. Additionally they also ignore color and contrast change as other sensor technologies find hard to deal with. Balluff Ultrasonic sensors are offered in many different housing sizes with multiple scanning ranges to choose from. If you would like to discuss your application in further detail please don’t hesitate to contact one of our Technical Support Specialist @ 1-800-543-8390

  3. What is the difference between a color sensor, mark sensor and contrast sensor?

  4. Shawn Day says:

    Hello Bob,

    Inductive proximity sensors are designed for detect ferrous metal targets. I have below a short description on the basic operating principles of an inductive proximity sensor.

    • Voltage is applied to the sensor; an electromagnetic field is generated by the coil and extends out the face of the sensor.

    • When a metal target enters the sensing zone, an eddy current is induced in the metal by the electromagnetic field.

    • As the metal gets closer the eddy currents increase, this removes power from the electromagnetic field which lowers the amplitude of the operating frequency.

    • This loss of amplitude is detected by the trigger circuit and the sensor’s output is energized.

    Thanks for your question.

  5. How do inductive proximity switches work?

  6. Can my sensor be installed in a wash-down area?

    1. Shawn Day says:

      Hello John,

      Balluff manufactures a specific product line of sensors and cables that are designed for wet, washdown applications. Balluff “Proxinox” sensors are also resistant to aggressive cleaning agents, coolants and oils. If you have a washdown area Balluff “Proxinox” sensors will serve you well. Some of the key features are listed below.

      • Double insulated housings
      • Stainless Steel housings
      • PUR cable material
      • Optional PUR cable with Stainless Steel coupling nuts

      Thanks for your question.

  7. If I wire my proximity sensor wrong, will it damage it?

    1. Shawn Day says:

      Hello Steve,

      Great question and thanks for your comments. Balluff proximity sensors typically have what’s called “Reverse Polarity” The sensors have an internal circuitry that protects the device from damage due to improper installation or if the proper specified voltage is not maintained.

  8. What is the difference between a 2-wire, 3-wire, and 4-wire sensor?

    1. Shawn Day says:

      Hello Derek,

      We receive many questions with regard to your question… In short, a two wire sensor can operate with a sinking (NPN) or sourcing (PNP) output. They also required a larger voltage drop than a typical 3 or 4 wire sensor… around 5V drop.

      3 and 4 wire sensors are specific to a desired output. PNP or NPN meaning if an application calls for a PNP sensor and NPN offering would not work due to different wiring requirements.

      4 wire sensors operate on the same principle as the 3 wire units however; the 4th wire allows the sensor to be wired with an N/O or N/C output. For example a 4 wire could use pin 2 for an N/C output or pin 4 for an N/O output. A typical name for a 4 wire sensor is “Complementary”.

      Thanks for your question.

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