Thermal resistance signal transmission issues
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For the remote transmission of PT100 signals from three-wire thermistors, it is not clear whether it is more accurate to transmit the resistance signal directly in three-wire format or to convert it into a 4-20mA signal for transmission. There are some regulations regarding this, but I am not very familiar with them.
First, it depends on how far the transmission distance is; second, it depends on the purpose for which the temperature is being measured. Both transmission methods can meet your measurement requirements.
This post was last edited by liu530014416 on 2022-11-14 at 17:28. The temperature change module is advantageous: firstly, it standardizes the cables, and secondly, it standardizes the DCS cards. Otherwise, it is necessary to purchase three-wire cables, and the DCS cabinet will need to be equipped with corresponding temperature change safety gates or thermistor cards. The entire set of three-wire cables isn’t any cheaper than a temperature sensor module
. There is no difference in accuracy. However, the problem of interference from on-site temperature variation signals is easy to solve, and the control room becomes neater as well. .