why to use 3 wire at RTD ?
what's the reason for
common wire ?
Answers were Sorted based on User's Feedback
Answer / prince
RTD's work on the principle of RESISTANCE. The two working
wires might have different lengths, so different resistance.
Third wire is used for compensating the extra resistance so as
to get accurate o/p. Third wire is in parallel connection with
one of the wire. In 4 wire RTD, the compensation is more.
Is This Answer Correct ? | 13 Yes | 0 No |
Answer / carl_ellis
It is correct that an RTD indicates a change in temperature
by a change in resistance of an element.
The change in resistance must be monitored electronically
and any circuit connected to an RTD will include copper lead
wires which will add resistance to the circuit.
The problem is not that the lead wires will have different
lengths, the problem is that any copper lead wire has some
resistance which will contribute to a voltage drop from the
source current and appear to be the resistance of the RTD
element. Any contribution of resistance to the measurement
is an error.
Two lead wires connect to the RTD element and a 3rd lead
wire is used to compensate for the added lead wire
resistance so that the lead wire resistance is eliminated
and only the RTD resistance is measured and used to
calculate temperature.
Carl Ellis
Measure First
Is This Answer Correct ? | 10 Yes | 1 No |
Answer / rathod mukesh r
If 2 Wire rtd use , The distance is more between remote location (Rtd) And dcs panle then error occur in reading of temperature. Means if wire length is increases then its own resistance also increase so proper reading is not transmited via 2 Wire. In 3 Wire rtd these error is remove using compensasion lead.
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / yugesh shah
3rd wire is called compensation wire , when RTD is installed
far away from control room or where we get indication then 2
wire RTD fails to send appropriate sign al due to
temperature effect or atmospheric changes so 3rd wire is
helpful to send error free signals or resistance
Is This Answer Correct ? | 0 Yes | 2 No |
why we us isolation barrier in hazardous area how it works to protect the area and please clarify its current flow.
How would i calibrate a new commissioned flow transmitter???
how can i communicate with non-national instruments device with pc via labVIEW8.2
3 Answers Google, Mico, National Instruments,
why we use npn sensor in vibration monitoring system
Someone Please tell me what are the Pre-Commissioning activities in a Thermal Power Plant for an instrumentaion Engg.
NAME ANY TWO ELASTIC PRESURE SENSOR?
what is difference btween rotameter and orifice plate?
How signals can be taken through modbus?
sir i m preparing for BARC but i am not getting any papers to prepare for this exam so please send me some sample papers to my i.d for the preparation of barc.
I am going to attend a recruitment drive by Schneider in 2 weeks. They have a technical test in the beginning. I would like to know what are the areas i should concentrate on while preparing for the test. My major is Electronics and Instrumentation.
Waht is surge in compressors and how to control it?
Why DP level transmitter preferred for closed vessels and Radar level transmitter for open tanks??