Route Of Electrical Load Cell Input And Output - OHAUS CKW3R Service Manual

1.8 HOW LOAD CELLS OPERATE
The difference in the output signal before and after the mass was placed on the platform is
taken, interpreted and displayed.
Strain
Gauges
Compression
4 strain gauges
connected as a
Wheatstone
Bridge
Figure 1-3. Route of electrical Load Cell input and output through Wheatstone Bridge circuit.
A Load Cell is a force sensor, which receives a voltage (excitation) from a regulated power
source in the Indicator, and sends back a low-voltage milli-volt (mV) relative to the force applied.
The Load Cell signal is read by the Indicator, which converts it to a numeric value and shows it
visually. This output value increases as weight is loaded to the Load Cell.
For example, a 500kg Load Cell with 2mV/V output and 5V excitation would have a change of
0.02mV per kg change in the load, that is, 10mV/500=0.02mV per kg. At a load of 250kg the
signal voltage would thus increase by 5mV from the value measured at no load.
CKW Base Series Service Manual
LOADCELL
2 mV/V
Tension
CHAPTER 1 INTRODUCTION
Tension
Compression
OUTPUT (milli volts)
1-5 Ohaus Corporation www.ohaus.com
+Excitation
(Supply)
INPUT(volts)
Excitation
–
(Supply)
+Sig
Sig
–