DayTronic 3000PLUS - Page 67

3KP64 - 4.8
3000PLUS WITH 5D64 INSTRUCTION MANUAL V. SB.2
Daytronic Corporation
2211 Arbor Blvd. Dayton, OH 45439 • (800) 668-4745
Tel: (937) 293-2566 • Fax: (937) 293-2586 • www.daytronic.com
two independently and accurately known calibration
points (“ZERO” and “SPAN”).
As explained below, TWO-POINT calibration of the
5D64 includes optional ± midscale LINEARITY correc-
tions. Both calibration techniques allow NEGATIVE
SYMMETRY adjustment of the 5D64’s output (up to ±2%
of full scale).
NOTE: Whenever you intend to apply both “absolute”
and two-point calibration to the 3000PLUS,
absolute cal-
ibration should always be performed first.
Also note that both calibration methods provide a
means to
restore the 3000PLUS to the calibration state
that existed before the last calibration was performed.
ABSOLUTE CALIBRATION
In absolute calibration, the required calibration values
are calculated “off-line” by the Configurator software,
based on the numbers you enter in the
ABSOLUTE
Calibration
page (shown in Fig. 13). Calibration infor-
mation will not be issued to the 3000PLUS or saved to
the present configuration until you press the button
labeled
“Save and Send Calculated Calibration Val-
ues,”
or until the entire instrument configuration is sub-
sequently downloaded.
The
CAL3 field will always contain the 3000PLUS instru-
ment’s current
Full-Scale Reading in Engineering
Units (FSU)
value. CAL3 therefore specifies the
desired relationship between the 5D64 module’s
mea-
sured engineering units
and its high-level ±5.000 VDC
output, given the full-scale
input range (RNG) for
which the 5D64 is currently set.
NOTE: The number in the CAL3 field cannot be
changed in the
Instrument Calibration window. To
modify
CAL3, you must close the window, return to the
Instrument Setup page, and enter a new Full-Scale
Reading value.
The
CAL4 field lets you enter an optional zero correc-
tion term (“offset”)
to be continuously applied to the
5D64 module’s measurement signal, expressed either
in
engineering units or in millivolts. In either mode,
CAL4 should be entered with the desired plus/minus
polarity: a
positive offset value will be algebraically
added to the module’s output signal; a negative offset
value will be algebraically
subtracted. The initial
(default)
CAL4 setting for every 3000PLUS configura-
tion is zero (“0”).
Whether other calibration values need to be entered in
addition to
CAL3 and CAL4 will depend on the Calibra-
tion Mode
selected by the user.
If the installed 5D64 module’s received input is to repre-
sent
voltage itself—as would be the case if the instru-
ment were to be used as a scaled voltmeter—then the
VOLTAGE mode of absolute calibration should be
selected. In this case, the
CAL1 and CAL2 fields are
not required and will not appear.
If, on the other hand, the 5D64’s received input is to
represent
an analog of some parameter other than volt-
age
—as would be the case if the instrument were con-
nected to a DC-to-DC LVDT for measurement of
physical displacement—then one of the two forms of
the
TRANSDUCER calibration mode should be select-
ed:
• Select
TRANSDUCER @ VOLTS FS if you want the
sensitivity of the source transducer (
CAL2) to be
expressed in volts, full scale. In this case, the inter-
nal absolute calibration calculations require entry of
the
source transducer’s full-scale rating (CAL1).
• Select
TRANSDUCER @ VOLTS/UNIT if you want
the sensitivity of the source transducer (
CAL2) to
be expressed in volts per (measured) unit. In this
case, the transducer full-scale rating (
CAL1) is not
entered.
Regardless of the selected sensitivity mode, the fixed
“sensitivity” relationship between an electrical stimulus
and the output response of the source transducer must
be entered in the
CAL2 field. This value is normally
supplied by the transducer manufacturer.
To summarize, the first four absolute calibration values
you will enter for a 3000PLUS with 5D64 are as follows:
Transducer Information:
CAL1:
Transducer full-scale range
in engineering units
—required only for TRANSDUCER
MODE with sensitivity in
VOLTS, FULL SCALE
CAL2:
Transducer sensitivity (in V)
—required only for TRANSDUCER
MODE (either sensitivity mode)
4. SOFTWARE CONFIGURATION
AND CALIBRATION
Fig. 12
Typical Asymmetry