Re: choose a sensor - TDT vs TDR

[Marty Grogan]

Oops - this message must have slipped through a crack.. sorry Marty.
   Bruce

> Time domain methods (reflectometry--TDR, transmissometry--TDT) measure the
> time a fast pulse edge takes to travel along a section of transmission
> line.

Note that if a sine wave is used for TDT, no difference exists between TDT and
phase methods, i. e., sine(theta) = sine(omega*time + phase).  Since omega is
constant, time and phase become equivalent within a scaling constant and a
static offset.

Since any realizeable harmonic wave can be represented using a sum of sine
waves, no theoretical difference exists between TDT and phase methods.
Therefore, any practical effect in mesurement differences, all other parameters
being equal, would be due only to the fact that dielectric properties exhibit
some sensitivity to frequency.

Marty Grogan