ECG Machine Repair & Calibration
An ECG is a measurement, and a diagnosis is made from its shape and timing. If amplitude or paper speed is out, the trace still looks entirely convincing — it is simply wrong in ways no one reading it can see.
What we service
- 3-, 6- and 12-lead resting ECG machines
- Stress and exercise ECG systems
- Holter recorders and analysis units
- ECG modules built into patient monitors
What calibration actually checks
ECG interpretation depends on millimetres and milliseconds. We verify both against a calibrated simulator rather than relying on the machine's own internal reference:
- Amplitude — the 1 mV calibration pulse produces exactly 10 mm deflection at standard gain
- Paper speed and timing — intervals measured at 25 and 50 mm/s, since interval measurement drives diagnosis
- Heart-rate accuracy across the clinical range
- Lead integrity — every lead and every wire, individually
- Filter behaviour — that mains and muscle filters clean the trace without distorting genuine morphology
- Electrical safety — leakage current, since the patient is directly connected
Most "broken" ECG machines are not broken
By some distance the most common ECG complaint is a noisy or wandering trace, and the machine is rarely the cause. Lead wires fail internally where they flex near the connector, showing nothing on the outside. Electrodes dry out in the packet. Skin preparation gets skipped on a busy list. We test each lead individually to separate a genuine amplifier fault from a lead-set that simply needs replacing — which is a far cheaper conversation.
The second most common call is printing: faded traces, jammed paper, or blank sections. Usually a thermal print head needing cleaning or replacement, or paper that is not the correct thermal stock for the machine.
Documentation
You receive a certificate recording measured amplitude and timing against specification, lead-integrity results, electrical safety readings and the next service date — formatted for SAHPRA and ISO 13485 audit files.
Book an ECG Service
Describe the symptom — noisy trace, printing fault, or routine calibration.
Common questions
ECG FAQs
Often not. Internally broken lead wires are the most common cause and they look perfect from the outside, because the break is inside the insulation where the cable flexes. Dried-out electrodes and skipped skin preparation account for most of the rest. We test each lead individually so you are not replacing a machine that needs a lead set.
Annually is the usual interval, and it should include electrical safety testing because the patient is directly connected. Calibrate sooner if the machine has been dropped or repaired, or if printed traces look different from what staff are used to seeing.
Yes, for all major machines. Using the correct thermal paper for your specific model matters more than people expect — the wrong stock produces faint traces and can shorten print-head life considerably.
Yes. The ECG channel in a multi-parameter monitor is tested with the same simulator and to the same standard — see our patient monitor service if that is what you need calibrated.
ECG giving you trouble?
Describe the symptom to a technician — most are diagnosed over the phone.