Users’ Manual
EDI-53 Series Digital Indicator
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5
SETUP
The process of entering the transducer calibration coefficient in the internal memory of the EDI-53
indicator is called ‘Setup’ and the portion of memory earmarked for this process is known as the setup
memory.
Because this is a very critical information, to guard against accidental modification of entered data the
‘Setup’ function has to be activated through a special power on sequence.
5.1
Preparing Setup data
Before entering setup you should collect all relevant information and note it down on paper. At the end of
this manual we have included a specimen of a suitable data entry form. You can make photo copies of
this form and use it for collecting setup information.
Transducer manufacturers generally supply transducer calibration coefficients in two different forms for
calculation of parameter value in engineering units. The most common practice is to mention the Linear
Gage Factor and the Initial Reading or the Offset. For high accuracy transducers the manufacturer may
additionally specify 2
nd
order Polynomial calculation constants. Calculation using both these methods is
explained below:
Parameter calculation using Linear Gage Factor
For calculation using Linear Gage Factor, two constants
G
and
R
0
are supplied.
P = G (R
1
- R
0
)
where, P is Parameter value in engineering units,
G
is Linear Gage Factor (or simply Gage Factor)
R
0
is Initial Reading in Volts that may either be supplied by the manufacturer or determined at the time of
installation. (Some manufacturers may instead specify an Offset value)
R
1
is the current reading in Volts during observation.
Parameter calculation using 2
nd
order Polynomial
For calculations using a second order Polynomial, three coefficients,
A
,
B
and
C
are supplied.
P = AR
1
2
+ BR
1
+ C
where,
P
is parameter value in engineering units,
R
1
is the current reading in Volts during observation’
A
,
B
and
C
are called polynomial constants.
The setup form has seven columns. The entries to be made in each column is explained below.
•
Ch No
.— Enter the channel number (i.e. transducer number) that you want to assign to the
transducer. It is recommended that for ease of reference you assign the channel numbers
serially from 00 to 99 in ascending order.
•
Tag No
. — You can optionally enter an associated identification number in this column if such a
number tag has been assigned to the transducer during installation.
•
Transducer type
– Enter the type of transducer, e.g. strain meter, peizo meter, displacement
meter etc.
•
Units
— Enter the proper engineering units in which the parameter value is to be reported. You
can only use those symbols which are provided in the indicator.
•
Initial Reading or Coefficient C
— For Linear Gage Factor calculation enter the value of initial
volts. In transducers whose zero value do not change on installation (absolute reading) this figure
