Filtering noise from an analog output signal

[Ronak2]

Hello all,

I'm running an experiment which involves heating a mixture of air and fuel. I'm using some temperature controllers to regulate the temperature (displayed as a processed variable) at which I'm heating the mixture.  With this setup I'm trying to record the Processed variable using LABVIEW SignalExpress. I've attached a rough figure of my setup. I'm reading temperature using SignalExpress, converting it to a voltage signal and feeding it to the Heater controller so that I can regulate the temperature simulatenously while recording it. However, I seem to be getting a lot of noise on my output signal because of which I'm reading wrong temperatures on the heater controller. I plugged in an oscilliscope to check out the noise and it seems to be coming from various sources. Is there some way of filtering the signal or shielding it from noise?

All help appreciated,

Thanks,

Ronak

[HeatherBaker]

Hi Ronak,

There are a few things that need to be clairifed to get a better understanding of your system.  You sketched the SCB-68 in your drawing; however, this is the connector block.  What data acquisition board is connected to the SCB-68?  What type of noise are you seeing?  What are these different sources?  Did you check the input or output with the oscilloscope?  How are your thermocouples grounded.  This will help understand the issue more clearly- thanks!