Ultrasonic vs Prox Switches for Diameter Measurement

When deciding whether to use an  ultrasonic sensor or proximity switches for you diameter measurement it is important to know the advantages and disadvantages of each so you can utilize the best device for the unique requirements of your process. Here we take a look at those.

 

Ultrasonic Sensorus4 ultrasonic sensor

Advantages

  • Always knows precise diameter before the machine starts.
  • Push button calibrating
  • Only one sensor to mount

Disadvantages 

  • Accuracy will be affected by significant ambient temperature variations.
  • If winding/unwinding both under and over the roll, it may be difficult to find a mounting position that will not interfere with loading and unloading the roll.
  • More expensive than prox switches.

 

Prox Switchesproximity sensor

Advantages

  • ½ the price of Ultrasonic
  • No interference with roll loading and unloading
  • Extremely accurate

Disadvantages

  • Needs to see at two pulses from the unwind/rewind roll before it knows the diameter.
  • Pick-up rings may need to be manufactured to insure enough pulses