(2) Mains inteference
                  It is the most common fault. It is charactersed by a very regular wave with ''Sawtooth'' appearance. Source of the interference may be:
(a) Any electrical appliance or power cable in close vicinity. y and dirty 

(3) INDISTINCT BASE LINE:

    This results from incorrect system pressure or heat adjustment. 
    This faults requires repair by service engineer.

(4) MUSCLE TREMOR 
   If the patient is tense, felling cold or uncomfortable or there is no suitable support limbs, fuzzy and irregular baseline in recorded on the tracing. the cause should be identified and removed.


   (5) WANDERING BASELINE;
                                                                                                                                                                                 THE POSSIBLE CAUSE ARE:


(A) High skin nesistance because of poor patient preparation.
(b) Movement of patient or C.C.G cable or electrode during recording.
(c) Over expansion of chest with respiration.
(d) Over expansion of chest with respiration.
     The cause should be identified and removed.

(6)
INTERMITTENT AND NOISY WAVES: 
  The possible cause are:
        (a) Loose connection in the electrode and E.C.G. cable system or between the skin and electrode. 
        (b) contaminated electrode gel or dry and dirty electrodes or skin. 
        (c) if The fault pesists after rectification of the above causes then fault within the instrument                    should be suspected.