4-20ma analog output sensor

[nmark]

I need a sensor that is capable of sensing a lift that moves from 1-6 feet from where the sensor is mounted.It also is being used in a washdown area with complete submersion of sensor in water on a daily basis for approximately 2 minutes.The ideal sensor would be 24v d.c. with 4-20ma output.Any suggestions would be appreciated.

 

[itsmoked]

A tape measure style unit that converts its rotation to your 4-20mA.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ScottyUK]

Google [blue]draw wire encoders[/blue] for hundreds of hits on potentially suitable items. You really need to specify the accuracy you need in terms of linearity, resolution, and repeatability. Unless you're looking for accuracy down to a handful of [μ]m then a draw-wire type is likely to give the best trade-off between cost and accuracy.

When you say 'submersion' are you talking in terms of the whole unit being sunk into a tank of liquid, or an enthusiastic wash with a hose? If total submersion is likely, Balluff's Micropulse sensors are available in stainless steel with an IP68 rating. They are very accurate and quite expensive. I've used them in some awful environments and provided the sensing element is protected against physical impact damage they are fairly immune to environmental conditions.

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