Hardy Process Solutions HI 1769-WS, Operation And Installation Manual

Page: 63 / 82

Chapter 5 - Calibration
5-3
a. The Weigh Module is designed to sup-
ply 5 VDC excitation to as many as four
(4) 350 Ohm load cells/points.
b. The expected output from each load
cell/point depends on the mV/V rating
of the load cell/point and the weight.
c. For example, a 2mV/V load cell/point
will respond with a maximum of 10
mVDC at full weight capacity of the
system which includes the weight of the
vessel and the weight of the product as
measured by the load cell/point.
d. If the load cell/point weight capacity is
rated at 1000 pounds, the load cell/point
will be 10 mVDC at 1000 pounds, 7.5
mVDC at 750 pounds, 5 mVDC at 500
pounds and so on.
e. A zero reference point will vary from
system to system depending on the
“Dead Load” of the vessel. “Dead Load”
is the weight of the vessel and appurte-
nances only, with no product loaded. In
our example we will assume the dead
load to be 500 pounds. (See Fig. 5-2)