Distance Measurement sensor Required

[anand.usic]

Hello,
Am looking for a sensor that can give me distance variation of an object millimeter accuracy. Is this type of sensor readily available as module. Please give me your suggestion and give the link if you find it.

 

[Reloadron]

You don't mention the distance you want to measure? The distance between the read head and the target?

Also, to what uncertainty as in how accurate?

Ron

 

[irbirb]

a popular approach has been to pull the sonar (auto-focus) elements from old polaroid cameras and use those. i don't know how accurate you can get with those.

 

[atferrari]

Google for LVDT.

 

[OlPhart]

There's a cute build in Cypress's PSOC chip series that does sonar to an LCD in 1 chip, fun toy. However, millimeter accuracy isn't done with sonar, look at the wavelengths vs sensor thresholds. Then again the OP is Way Vague. <<<)))

 

[irbirb]

However, millimeter accuracy isn't done with sonar, look at the wavelengths vs sensor thresholds.

unless you've got a bat for sonar!
or a E-220B/215. then you can rock better than 0.1mm accuracy.
the polaroid's sonar is only accurate to about 2cm with a range of 15cm-10m.

 

[cr0sh]

Unless the distance needs are small, probably looking at something like a laser distance sensor (something from SICK or Hokuyu or similar - neither are cheap options) to get that accuracy...

 

[OlPhart]

Ok, a new module to me, nice units. I've always classed ultrasound as ~25kHz to 50kHz and, therefore the lower resolution. DigiKey has a 65kHz transducer & Mousers' is 40kHz. Wikipedia has it going 500kHz+. Got some tips on transducers for 100kHz+? It sure would expand my sonar use. TNX <<<)))

 

[Reloadron]

Since the OP has yet to return and us not really knowing his goals it is hard to say what would work best for his application.

However, I recently did a few projects using products from Micro-Epsilon using their LASER Triangulation models from this series and like most sensors in this category they work great but also carry a price tag around $4,500 USD per unit. Really nice stuff and I like the 0 to 10 volt or 4 to 20 mA output feature. Nice for recording.

For more reasonably priced LVDT units I like the Honeywell Longfellow series of units. They are pretty reasonable in the $400 USD price range. Much cheaper LVDTs can be had depending on the application requirements.

Another popular solution to distance is the use of a string pot or yo yo pot as I call them. They come in a wide price range depending on how accurate you want to get, how linear can you make a pot? I do like those for a good many applications. Unimeasure Linear Position Transducers is a good line that I like.

Overall my take is that a distance sensor is chosen on the application and unless the OP shares that information with us there is no way to tailor a type of position sensor to his application. There is distance, accuracy and mechanical restraints and I have no clue what the OP has.

Ron

 

[irbirb]

Ok, a new module to me, nice units. I've always classed ultrasound as ~25kHz to 50kHz and, therefore the lower resolution. DigiKey has a 65kHz transducer & Mousers' is 40kHz. Wikipedia has it going 500kHz+. Got some tips on transducers for 100kHz+? It sure would expand my sonar use. TNX <<<)))

i found this: https://www.electro-tech-online.com/custompdfs/2011/03/pos96ch4.pdf but really don't know anything about them or their prices. something in the order of 150KHz.

Really nice stuff and I like the 0 to 10 volt or 4 to 20 mA output feature. Nice for recording.

interesting. recording on audio tape? i'd like to know a simple method for doing this 0.0
could be really handy indeed!

 

[Reloadron]

interesting. recording on audio tape? i'd like to know a simple method for doing this 0.0
could be really handy indeed!

No audio tape, recording using charting software. The test I use the LASER interferometer in involves dropping a rod and measuring the bounce. The unit chosen was the model ILD 1700-20 from my link. That unit has a start of measurement range of 40mm and an end of measurement range of 60mm with 50 mm being the point of reference. The unit provides 0 volt out at 40mm and 10 volts out at 60mm. Therefore from start to stop I have 20mm and 0 to 10 volts over that 20mm.

That analog output is fed to my software. For this particular test I use one of these units which gives me 14-bit, 150kHz waveform recording capability. More than adequate speed and resolution for this particular test. Within the software on the chart the 0 to 10 volts is scaled for inches. Anyway, no audio. It would just be a rattling noise followed by a bang then a softer bang.

Ron

 

[irbirb]

No audio tape, recording using charting software. The test I use the LASER interferometer in involves dropping a rod and measuring the bounce. The unit chosen was the model ILD 1700-20 from my link. That unit has a start of measurement range of 40mm and an end of measurement range of 60mm with 50 mm being the point of reference. The unit provides 0 volt out at 40mm and 10 volts out at 60mm. Therefore from start to stop I have 20mm and 0 to 10 volts over that 20mm.

That analog output is fed to my software. For this particular test I use one of these units which gives me 14-bit, 150kHz waveform recording capability. More than adequate speed and resolution for this particular test. Within the software on the chart the 0 to 10 volts is scaled for inches. Anyway, no audio. It would just be a rattling noise followed by a bang then a softer bang.

Ron

oh dang, that's drool worthy stuff!
i'd use it for z-axis keying during high-speed image capture and revolutionize hollywood... well, if i was into that sort of thing..

i'm guessing that there's some lower rez audio-tape recording for 0-10 volts out there because that was the standard of pre-DMX controllers of theatrical lighting. something i've been gearing up to work with in the future... but on the cheap... probably homebrew solutions for sequencing old dimmer packs.