Rtd_Temperature Sensor

there must be no wire joint from PID to SENSOR POINT, & cable must be of wire wound, & to prevent from harmonic progression, ur cable must not dressed with power cables in parrlel

This way perhaps?

John, perhaps guest has to measure in an electrically noisy environment and/or he wants to delete any DC-errors due to temp-changes in his amplifiers in order to get extreme precision (1/100 or even 1/000 K is no problem). For such applications we have used phase-sensitive amplifiers where the resistor is driven by AC of some kHz. The following amplifier will take only that frequency (eliminating all noise of other frequencies around and all DC-errors existing in the whole chain between sensor and full-wave-rectifier at the end). In this case low-inductance resistors will possibly make sense.
Regards Uwe

True uweka, I've used synchronous demodulation of an ac signal many times to increase sensitivity etc...

But with a low resistance perhaps 100 ohm and a fixed inductance/capacitance of lead wires and sensor, the effects can be nulled out i.e. they would be seen as a fixed phase shift.

But your point is taken, although many of the platinum RTD are made by thin film plating of platinum on to a substrate, so inductance should be less of a problem compared with the lead impedance?

John.

Temp. cannot vary at Audio and +++ frequencies.

So why bother to reduce Inductance.

If there is a great urgency-go for Bifilar winding - one nullifying the other.

Power from a DC voltage source.