User guide

4 ELECTRICAL CONNECTIONS
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OPTISYS SLM 2100
www.krohne.com 03/2014 - 4002737302 - MA OPTISYS SLM 2100 R02 en
4.3 Description of electrical symbols
Symbol Description
mA meter, 0...20 mA or 4...20 mA and other, R
L
is the internal resistance of the
measuring point including the cable resistance
Internal DC voltage source
Controlled internal current source in the device
Switch, NO contact or similar
Input, galvanically insulated
PTC resistance
Symbol for LED
Symbol for the protection switch
.book Page 22 Wednesday, April 30, 2014 1:39 PM