Tolerance indicator - accurate matching to within 0.25%

2-50 - elektor february 1982 tolerance indicator The advantages of the circuit speak for themselves. Although calculating toler- ances by measuring resistors is a pretty straightforward job, it is of course much more practical to be able to compare values with a constant reference. Now it can be seen at once whether the resistor under test is the right one or not, without having to go in for tedious calculations. In most cases, this method will afford a great deal more accuracy than using digital multimeters. The tolerances are indicated immedi- ately and there are no problems with drift. The circuit does not require any critical resistors and/or reference voltage sources. A single preset serves to cali- tolerance indicator accurate matching to within 0.25% This useful circuit helps to match resistors by comparing their values and indicating any difference between them. This enables tolerances as low as 0.25% to be calculated with accuracy. The circuit does not even need to be c...