>It happens to all of us from time to time, you think you know what the readings should be, and bang out of the blue your instruments starts speaking a different language. The first thing to say is that your instrument may in fact be giving the correct reading and it may reveal that something is wrong with the installation. Failling that though, it is worth bearing in mind that atmospheric conditions such as heat, cold, and damp influence what your meter tells you. Next time your meter goes south, check whether or not there have been problems with things like rats that are quite partial to pvc cable.
A word of warning though do not assume the worst, some of the basic things are equal contributors to error. Ask yourself, is the instrument properly calibrated, do the batteries or the instrument leads need replacing, it is always worth carrying extra leads and batteries for this exact reason. Finally, user error the faulty object may in fact be you, READ THE INSTRUCTIONS-enough said!
Mastech Training Ltd
Fairgate House
205 Kings Road
Tyseley
B11 2AA
0121 707 2727
www.mastechtraining.com