Some Notes About Accuracy - TENTECH MPK-254 Manual De Uso

6. Some notes about accuracy

In order to obtain the specified accuracy, the operator has to adjust the
test current to a value higher than the 80% of the nominal value. If it were
necessary, it is possible to use a lower current, but by doing this the
accuracy will be affected.
MPK-254 has an auto-compensation system that automatically eliminates
the error produced by internal offset. Thus, it is not necessary to carry out
measurements by reversing the polarity in order to compute the average
value. Nevertheless, if the operator suspect that there is a difference of
temperature between the contact points that would can generate
thermoelectric voltages, it is necessary to carry out two measurements by
reversing the current cables and so, the circulation sense of the current
through the resistance under measurement. The resistance value to be
measured will be the average between the values in one sense and in the
contrary (direct and inverse current).
12