Range And Span Consideration - ABB PGX100 Operating Instruction

8 P G X 1 0 0 A N D PA X 1 0 0 | P R E S S U R E T R A N S M I T T E R S | O I/ P G X / PA X 1 0 0 - E N R E V. C
. . . Transmitter overview
. . . T ransmitter components overview
The different models of the PXX100 series have different mechanical constructions of the process interface.
PGS100/PAS100 models have a single hydraulic circuit for which filling fluid is selected directly in the ordering information.
PXF100 and PXD100 models have a 2-circuit construction: the primary circuit (i.e., the sensor/transducer circuit) is always filled as
per factory standard (silicon oil) while the second circuit filling fluid (i.e., process connection circuit) can be selected by the
customer as per the ordering information.
The secondary circuit filling in PXF100 is the one to be selected during the device configuration (i.e., fill fluid type) while for PXD100
the secondary circuit filling can be selected during the codification of the S26 remote seal accessory.
In case of need for a different filling on the primary circuit (i.e., the sensor/transducer circuit), this can be requested via the special
request (SR) process active in ABB.

Range and span consideration

The PGX100 and PAX100 Transmitter data sheet provides all information concerning the Range and Span limits in relation to the
model and the sensor code.
The terminology currently used to define the various parameters is as follows:
• URL: Upper Range Limit of a specific sensor. The highest value of the measured value that the transmitter can be adjusted to
measure.
• LRL: Lower Range Limit of a specific sensor. The lowest value of the measured value that the transmitter can be adjusted to
measure.
• URV: Upper Range Value. The highest value of the measured value to which the transmitter is calibrated.
• LRV: Lower Range Value. The lowest value of the measured value to which the transmitter is calibrated.
• SPAN: The algebraic difference between the Upper and Lower Range Values. The minimum span (MIN SPAN) is the minimum
value that can be used without degradation of the specified performance. The calibration span (CAL SPAN) is the difference
between Upper Range Value (URV) and Lower Range Value (LRV).
• TD: (or Turn Down Ratio) is the ratio between the maximum span and the calibrated span.
The transmitter can be calibrated with any range between the LRL and the URL with the following limitations:
– LRL ≤ LRV ≤ (URL - CAL SPAN)
– CAL SPAN ≥ MIN SPAN
– URV ≤ URL