Full Scale Value

An I/O device with an analog input measures over a nominal measuring span that is limited by an upper and a lower limit (the initial and end values). This can be seen in the product Description.

The range between the two limits corresponds to the equation End Value - Initial Value. This is the measuring scale or the dynamic range. The limit with the largest value is chosen as the full scale value of the respective product (also called the reference value) and is given a positive sign. This applies to both symmetrical and asymmetrical measuring spans.

Figure 1: Full scale value, measuring span

For the above examples this means:

• Measuring range 0...10 V: asymmetric unipolar, full scale value = 10 V, measuring span = 10 V
• Measuring range 4...20 mA: asymmetric unipolar, full scale value = 20 mA, measuring span = 16 mA
• Measuring range -200...1370°C: asymmetric bipolar, full scale value = 1370°C, measuring span = 1570°C
• Measuring range -10...+10 V: symmetric bipolar, full scale value = 10 V, measuring span = 20 V