Honeywell Sensing and Control 3
SC 2000, SC2001, SC3004
Rev. G, 008-0608-00
1.4 What is Signature Calibration?
1.4.1 Overview
A small integrated circuit is located either inside the transducer,
in an in-line package between the instrument and the transducer,
or in the connector of a cable. All data necessary to set up the
transducer with the instrument are stored (even linearity data),
and setup is automatic when a new transducer is connected to
the instrument.
The Strain-Gage Input channel of the SC Series is designed to
operate with Signature Calibration. It will automatically set itself
up with transducers which contain the memory device, but can
also be set up using a front-panel interactive procedure. The
Signature Calibration module can also be programmed from the
instrument’s front panel.
Signature Calibration is only available with unamplified strain-
gage transducers.
1.4.2 Benets
• Thetransducer’sCalibrationRecordisalwayslocatedwhere
it is needed most... with the transducer.
• Theinstrumentisalwayssetupcorrectlywiththetransducer.
• Interchangingoftransducersandinstrumentsisaquick
process.
• AUserCalibrationDataareathatcanbealteredbycustom-
ers to fit their requirements.
• AFactoryCalibrationSheetDataarea,unalterablebythe
customer, can be copied back into the User Calibration
Data.
1.4.3. Information Stored
The following information is stored inside transducers equipped
with Signature Calibration:
• Full-scalemV/V:Thefull-scalemillivolt-per-volt(mV/V)rating
of the transducer when its full load is applied; also called
“calibration factor”.
• Shunt-CalmV/V:Themillivolt-per-voltoutputofthetransduc-
er when the shunt calibration resistor is placed across its (-)
SIGNAL and (-)EXCITATION leads.
• ShuntResistance:Theresistancevalue,inOhms,thatwas
used to obtain the shunt-cal mV/V value above.
• Full-ScaleValue:Thefullscalevalueofthetransducer,in
engineering units.
• EngineeringUnits:Theengineeringunitsthatthetransducer
is calibrated in (i.e. pounds, grams, pascals, inches of water,
etc.).
• SerialNumber:Theserialnumberofthetransducer.
• ExcitationVoltage:Themagnitudeandtypeofsignalusedto
excite the transducer.
NOTE: The excitation voltage of the instrument is set to 5 Vdc
regardless of the value stored within the Signature Module.
• LinearizationPoints(optional):Thesecanbeusedbyan
instrument using Shunt Calibration or Millivolt-per-Volt Cali-
bration to correct any non-linearity in the transducer and thus
improve the accuracy of the system. An additional “multiple-
point calibration” can be purchased with the transducer that
allows linearity correction information to be placed into its
Signature Calibration module.