Range And Span Consideration - ABB 266 DDS Operating Instruction

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. . .2 Transmitter overview

Range and span consideration

The 2600T Transmitter data sheets provide 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