Omega PLATINUM Series User Manual page 28

PLATINUM S eries M eters U ser's G uide
To c alibrate t o a s pecific b ridge d evice, t he u ser m ust p rovide t wo k nown l oads a nd e nter t he
corresponding v alues. T his a llows t he d evice t o c alculate a s traight l ine c orrection:
Weight = I nput R eading X G ain + O ffset
Scaling o perations a llow t ranslating s ource ( input) s ignals t o s caled o utput s ignal u sing a l inear
translation d efined b y a S LOPE ( or g ain) a nd a n O FFSET. A s s hown b elow, ( X1, Y 1) a nd ( X2,Y2) d efine
two p oints o n a l ine t hat h as a c ertain S LOPE a nd O FFSET. K nowing t he S LOPE a nd O FFSET a llows
determining t he O UTPUT v alue f or a ny g iven I NPUT v alue u sing t he e quation:
Output = I nput X S LOPE + O FFSET, w here
GAIN = ( Y2 -­‐ Y 1) / ( X2 -­‐ X 1)
OFFSET = Y 1 -­‐ ( GAIN * X 1).
The I nput r eading i s e xpressed i n t erms o f f ull s cale, w hich i s d irectly d ependent o n t he a pplied
reference v oltage w hich i s i n t urn d erived f rom t he e xcitation v oltage. D ue t o t he r atiometric d esign t he
absolute v alue o f t he E xcitation v oltage a nd e xact r esistor v alues d o n ot e nter i nto t he w eight
calculation.
If ( X2 -­‐ X 1) = = 0 , t he G AIN i s s et t o 1 a nd t he O FFSET i s s et t o 0 .
6.1.4.4 Bridge ( Ratiometric) I nput S caling
Reference S ection: I nitialization M ode ( INIt)
X
X
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