How to Protect the Measurement from Noise Interference?
Virtually every plant environment contains electrical interference sources like pumps, motors, variable frequency drives (VFD's) and radios as well as sources of electrostatic discharge and other electrical transients. Low level sensor signals from RTDs and T/Cs are very susceptible to Electromagnetic Interference (EMI), Electrostatic Discharge (ESD), and Radio Frequency Interference (RFI).
Sensor Leads act like an antenna for noise interference causing potentially very large errors in the measurement. The longer the leads (the antenna), the greater will be noise pick up. A transmitter is designed to reject common mode and normal mode interference as well as provide a high degree of immunity to EMI, ESD, and RFI.
Where possible and practical, transmitter should be mounted close to the measurement point to minimize potential noise pick up by the sensor leads, this is especially important for low level T/C signals which are especially susceptible to noise.
Sensor Leads act like an antenna for noise interference causing potentially very large errors in the measurement. The longer the leads (the antenna), the greater will be noise pick up. A transmitter is designed to reject common mode and normal mode interference as well as provide a high degree of immunity to EMI, ESD, and RFI.
Where possible and practical, transmitter should be mounted close to the measurement point to minimize potential noise pick up by the sensor leads, this is especially important for low level T/C signals which are especially susceptible to noise.
Date Published: March 7, 2019
Source: The Engineer's Guide to Industrial Temperature Measurement - 2013 Edition
Source: The Engineer's Guide to Industrial Temperature Measurement - 2013 Edition