Calibration Type Menu Item; Table 10-: Comparison Of Calibration Types - Honeywell SC Series Installation Instructions Manual

SC 2000, SC2001, SC3004

10.5.4 CALIBRATION TYPE Menu Item

This chooses the type of calibration technique to be used. There
are three methods that can be used to calibrate the transducer to
the Input Channel. Each has advantages and disadvantages as
described in the table below

Table 10-: Comparison of Calibration Types

RECOMMENDED...
...for most applications no
...when frequently yes
swapping transducers
...when best possible no
accuracy required
PROs and CONs
Relative accuracy good
Requires actual, no
calibrated loads to be
applied
Automatically cali- yes
brates with Signature
Calibration transduc-
ers
Max. distance of trans- 15 ft [5 m]
ducer from instrument
w/out sense wires
Max. distance of trans- 15 ft [5 m]
ducer from instrument
with sense wires
CALIBRATION TECHNIQUE
Zero-scale point from... applied
load
Full-scale point from... transducer
output
when shunt
resistor
applied
Linearity correction data
from... stored in
Signature
Module (if
available)
yes no
yes no
no yes
better best
no yes
yes no
50 ft 300 ft
[15 m] [100 m]
100 ft 300 ft
[30 m] [100 m]
applied applied
load load
internal applied
reference load
data 2-point:
stored in none;
3- or
Signature
Module (if 5-point:
available) applied
load
It is important to know your application in order to select the
appropriate calibration type. mV/V ("millivolt-per-volt") Calibra-
tion is recommended for most applications because it doesn't
require known loads and it allows easy swapping of transducers
equipped with Signature Calibration. When the best possible ac-
curacy is required, Known-Load Calibration is recommended.
The choices for this menu item are:
• "TYPE= SHUNT CAL" means Shunt Calibration. First, you are
prompted to apply the load entered in the "ZERO SCALE VAL-
UE" register. Next, the instrument inserts a known, precision
resistor into the transducer circuit, which causes a predict-
able apparent signal. The instrument then takes a reading
and adjusts itself using the "SHUNT CAL VALUE" register.
• "TYPE= MV/V CAL" means Millivolt-per-Volt Calibration. First,
you are prompted to apply the load entered in the "ZERO
SCALE VALUE" register. Next, the instrument takes a reading
from an accurate, internal mV/V reference. The instrument
then uses the "FULL SCALE MV/V" and "FULL SCALE VALUE" val-
ues in mathematical calculations to scale its tracking values.
• "TYPE= 2 POINT CAL" means 2-Point Known Load Calibra-
tion. You are prompted to apply the loads to the transducer
that were entered in the "KNOWN POINT 1/2" and "KNOWN POINT
2/2" registers. This technique assumes that the transducer is
linear, so the usual loads used are zero scale and full scale.
• "TYPE= 3 POINT CAL" means 3-Point Known Load Calibration.
You are prompted to apply the loads to the transducer that
were entered in the "KNOWN POINT 1/3" and "KNOWN POINT 2/3"
and "KNOWN POINT 3/3" registers. This technique can be used
to compensate for the non-linearity in the transducer. The
usual loads used are zero scale, half scale and full scale, but
you are not restricted to these loads.
• "TYPE= 5 POINT CAL" means 5-Point Known Load Calibration.
You are prompted to apply the loads to the transducer that
were entered in the "KNOWN POINT 1/5", "KNOWN POINT 2/5",
"KNOWN POINT 3/5", "KNOWN POINT 4/5" and "KNOWN POINT
5/5" registers. This technique can be used to compensate
for the non-linearity in the transducer. The usual loads used
are zero scale, one-quarter scale, half scale, three-quarters
scale and full scale, but you are not restricted to these loads.
The selection of the calibration type affects what menu items ap-
pear in the CALIBRATION DATA sub-menu.
008-0608-00
Rev. G,
Honeywell Sensing and Control 31