What is admittance RF level transmitter?

[abfer]

Are there any detailed information about it? I roughly know what it is from the product datasheets but i'd like to know it in more depth especially the theory behind it and may be some practical knowledge. Thanks.

 

[roydm]

I suggest you visit Drexelbrooks site and download one of their manuals, in the front it gives you a description

http://www.drexelbrook.com

Regards
Roy

 

[controlnovice]

Or try this:

http://tinyurl.com/d8d97l

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This is normally the space where people post something insightful.

 

[abfer]

Ok i already made a small research but i did not get the idea clearly. They say that the system also measures the resistance. What resistance? I don't think we can measure the resistance directly (by applying a dc voltage) in most cases. Do they measure the capacitance and the impedance and ignore the inductance and then extract the resistance? And how it helps to know the resistance?

 

[djs]

In most cases, an RF signal is sent dowm two conductors. The level being measured, usually water, forms a capacitor at the top level with respect to the two conductors. The two conductors also form an inductor. You then have an LC circuit in which the values of L & C vary according to the liquid level. Varying L & C values change the admittance seen by the RF generator.

 

[abfer]

Are you sure about the L-C? Because they don't mention about L but they do about R (resistance). And what's the mechanical structure? Are 2 condcutors is a must or can it be realized by one conductor like one probe capacitive sensors?