Zero and Span are alternative descriptions to LRV and URV for the 0% and 100% points of an instrument’s calibrated range. “Zero” refers to the beginning-point of an instrument’s range (equivalent to LRV), while “span” refers to the width of its range (URV − LRV). For example, if a temperature transmitter is calibrated to measure a range of temperature starting at 300 degrees Celsius and ending at 500 degrees Celsius, its zero would be 300 °C and its span would be 200 °C.
Similar Basic Questions in Industrial and Control Systems Engineering:
- What is Manual mode in Industrial measurement and control systems Engineering
- What do you mean by Automatic Mode in Industrial measurement and control systems Engineering
- What is FCE or Final Control Element
- What is Manipulated Variable, or MV
- What do you mean by controller in Industrial measurement
- What is Zero and Span in Industrial measurement and control systems
- What is Process Variable in Industrial measurement and control systems
- What is Setpoint in Industrial measurement and control systems
- What do you mean by Primary Sensing Element in Industrial measurement and control systems
- What is a Transmitter in Industrial measurement and control systems
- What do you mean by Lower and Upper Range values in Industrial measurement and control systems
- Define the term process in reference to Industrial Instrumentation
Reference and Further Reading: Basics of Industrial Instrumentation Handbook