1

Does anybody know how i would measure the distance between two points which will be no more than 50mm apart with accuracy to 1mm?

I want to record the distance between the two points in a database over time at frequency of 1 datapoint for every second.

Anybody know what sensors could do this?

closed as too broad by Majenko, fuenfundachtzig, Nick Gammon, TheDoctor, Ricardo Aug 20 '15 at 0:09

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • It is impossible for us to help you. It might help if you told us what you want to measure, what the environment is, etc. – Majenko Aug 12 '15 at 14:05
  • 1
    Some digital calipers have some kind of serial output. Not sure if your situation allows attaching one end of the caliper to the object you are measuring. – Gerben Aug 12 '15 at 14:32
  • Are the points visible and tangible? How fast do they move? Do you need a non-contact measurement method? – James Waldby - jwpat7 Aug 12 '15 at 14:44
  • @Majenko i want to measure the movement of 2 points on a material surface as it is stretched and released the points move apart and towards one another. The points are real and tangible. This of pins in cloth and we want to measure the distance between the pins. – Fearghal Aug 12 '15 at 15:08
  • 1
    If you can use a digital caliper as Gerben said I would go for that! The chinese ones are really simple to use: sites.google.com/site/marthalprojects/home/arduino/… They can basicly be used with a couple of NPN transistors, a few resistors, if you want it to be powered by your arduino you can use a simple voltage divider and a smoothing capacitor. – EJTH Aug 13 '15 at 12:35
1

want to measure the movement of 2 points on a material surface as it is stretched and released the points move apart and towards one another. The points are real and tangible. This of pins in cloth and we want to measure the distance between the pins.

If the two points can be made then you could use an Ultrasonic range finder. you could have one point be a wall (use balsa wood or something light) then the other could be the range finder. You might have to do a little bit of engineering for attaching the range finder to the pins on the cloth, but I believe it's doable.

heres an amazon link for a generic arduino range finder: http://www.amazon.com/RHX-Ultrasonic-Distance-Measuring-Transducer/dp/B00F6KLLGG/ref=sr_1_2?s=electronics&ie=UTF8&qid=1439459256&sr=1-2&keywords=range+finder+arduino

  • ultrasonic rangefinders can be inaccurate, certainly not accurate enough to measure 1mm. Also they are influenced by ambient temperature and other factors. – EJTH Aug 13 '15 at 12:33
  • Thx for the suggestion however i am looking to ind the distance between two points on material eg cloth. think of a t-shirt that has 2 dots on it. The tshirt is pulled and let go - i want to track the dots distance from each other duringt he action. a range finder could not do this accurately. or be practical. – Fearghal Aug 13 '15 at 12:38
  • well if you are decent at coding you could also use openCV to create a vision program that could track both points using a camera. although this might not yield in the most accurate measurements, it would only require a camera and time spent coding. – Ximidar Aug 14 '15 at 12:45

Not the answer you're looking for? Browse other questions tagged or ask your own question.