I saw the following paragraph in a book on electronics(The Art of Electronics Third Edition):
In Chapter 2x we will examine better ways of constructing logarithmic converter circuits, along with careful methods of temperature compensation. With such methods it is possible to construct logarithmic converters accurate to a few percent over six decades or more of input current. A better understanding of diode and transistor characteristics, along with an understanding of op-amps, is necessary first. This section is meant to serve only as an introduction for things to come.
More background information:
In this section, authors are introducing some kinds of converters, which generate an output voltage proportional to the logarithm of a current.
"Methods of temperature compensation" mentioned above can make converters insensitive to changes in temperature, which is desirable.
This is the last paragraph of this section.
My question is: How accurate are these converters?