Question

For higher accuracy, should R decade be large or small? Why?

Answer 1

For accuracy resistance decade should be small range of resistance.Decade boxes are passive devices that consist of switches and, depending upon the type of box, a series of resistors, capacitors, or inductors of different values arranged to form “decades”. Decades are set up in factors of ten and stepped such that any value 0 through 9 can be selected. For example, a resistance decade box may have a 5 ohm resistor, a 2 ohm resistor, and two 1 ohm resistors in the first decade. The second decade may have a 50 ohm resistor, a 20 ohm resistor, and two 10 ohm resistors. The third decade may have a 500 ohm resistor, a 200 ohm resistor, and two 100 ohm resistors. With this combination, this three decade box can be switched to any value from 1 ohm to 999 ohms in 1 ohm steps. Some decade boxes may have 6 or more decades to allow for very wide ranges and highly precise values. Decade boxes are characterized by their range, maximum resolution, and accuracy.