Indumart’sSEM1000 Series of Loop PoweredAnalogue Signal Isolators limit the magnitude ofthe signal so that unwanted, excessive voltages donot enter the instruments, ensuring safedecoupling of the sensor signal from the controlelectronics such as DCS, DAS, PLC, etc. TheSEM1000 Series signal isolators accuratelytransfer the analogue signal and at the same timeblock the DC continuity between the input andoutput of the isolator. Signal isolation also protectsthe data integrity by minimizing the effect of groundloop and electrical noise and provides a non-electric connection between input and output.
When analogue loops are grounded at more thanone point, due to potential difference at differentearth locations, currents will flow between any twopoints causing errors, noise and erratic signals.Even when the system has been designed to begrounded at a single point, leakage might occurthrough some instruments, such as ceramicinsulated thermocouple probes to introduce a pathto earth and causing errors.
The choice of isolator usually depends on whetherpower is available on the input side or the outputside of the isolator, and also if there is sufficientvoltage available in the loop to power a looppowered isolators.
Loop powered isolator(SEM1000) is poweredStability100 ppm / °Cfrom a 4-20 mA input signal side to providecomplete signal isolation and eliminate the earthloop. One important application of this small sizeisolator is isolating inputs to PLCs.