What are the functions of each of the three Grove EMG electrodes (red, white, black)

Products & Technology Grove
#1

Greetings,

For this EMG sensor: https://wiki.seeedstudio.com/Grove-EMG_Detector/

I believe one electrode is a reference (that can be placed farther away on the skin) and one is placed near the end of a muscle, and one near the middle of the same muscle. However, I’m not sure which color is which. If I want to experiment with monitoring another muscle besides the arm, what is general rule for where where the red, white and black electrodes should be placed for a given muscle?

Also, can the reference electrode be placed much farther away from the particular muscle, does it need to be within a certain number of inches on the same arm or leg, for instance – could the reference electrode be placed on the right arm, if the other two electrodes are on the left arm, for instance?

Thanks for any guidance!

#2

I did find this blog posting:


It has good information, but doesn’t identify what each electrode (red, white, black) is for. One link in the blog post raises an additional question. The sensor is only reporting one analog, value – which makes it a single channel measurement device. Wouldn’t this just mean a single reference electrode, and a single electrode measuring electrical activity. Is electrical activity measured at two places on the muscle and then added or averaged?

Thanks again for any help!