Explosion-Proof Linear Position Control Sensor: LVDT vs. Ultrasonic Comparison

[Big Jock]

Homework Statement

, [/B]I have to recommend a linear portion control sensor, that can be used in an explosive enviroment. Unsafe electrical contacts should be avoided and the case must not permit any dust or water.

Homework Equations

The Attempt at a Solution

. [/B]My thoughts are either a LVDT sensor or a ultrasonic sensor for the task listed above. Anyone have any thoughts on which would be the best out of those or a better suggestion?

 

[rude man]

LVDT is good if you can get one. They're used all over in aircraft. But they're ac devices so you'll need to phase-sensitively demodulate, probably.

Don't know nuthin' about ultrasonic sensors.
Some kind of sealed potentiometer, maybe?

 

[berkeman]

Homework Statement

, [/B]I have to recommend a linear portion control sensor, that can be used in an explosive enviroment. Unsafe electrical contacts should be avoided and the case must not permit any dust or water.

Homework Equations

The Attempt at a Solution

. [/B]My thoughts are either a LVDT sensor or a ultrasonic sensor for the task listed above. Anyone have any thoughts on which would be the best out of those or a better suggestion?

How severe is the environment? (Well, other than the explosions and all ) You could look into optical linear position sensing, as is used with handheld micrometers. But if the envrionment is dusty and wet, optical sensing may not be great. What resolution do you need? Are you going to build something, or just write a paper on the proposal?

http://i.stack.imgur.com/AtTpr.gif

 

[Big Jock]

The sensor case must not permit any ingress of dust or water so think the LVDT is the best option here...