Calibration, maintenance and electrical safety testing
These three terms are often used interchangeably, but they are different jobs:
Calibration: comparing what a device measures or delivers against reference equipment with a known value, for example checking an infusion pump's flow rate against a flow analyser. If the result falls outside the manufacturer's tolerance, the device is adjusted and tested again.
Preventive maintenance: inspecting, cleaning and replacing wear parts on schedule, such as filters, batteries and seals, before they fail.
Electrical safety testing: measuring leakage current and earth continuity to make sure the device is safe for patients and users. IEC 62353 is the standard for recurrent testing of medical electrical equipment and testing after repair.
A single service visit usually covers all three.
Why calibration matters
- Patient safety: a blood pressure monitor that reads low, or an infusion pump that over-delivers, can lead to treatment errors that nobody notices.
- Drift is gradual: sensors and mechanisms change with use, age and knocks. A device that looks fine may already be reading off.
- Audits: complete calibration and maintenance records show that equipment is managed systematically. If you are preparing for accreditation, check with your surveyors which records they expect.
- Equipment life: scheduled care catches small problems before they become major repairs.
What is checked on each type of device
The lists below are typical examples. The actual checklist must follow the manufacturer's service manual for each model.
Patient monitors: NIBP accuracy against a pressure simulator, ECG and SpO₂ function with signal simulators, pneumatic leak, and alarm function.
Infusion pumps: flow-rate and volume accuracy, the pressure at which the occlusion alarm triggers, and the air-in-line alarm.
Ventilators: delivered volume, pressure and FiO₂ against the set values, sensor accuracy, system leak, and every alarm.
AEDs and defibrillators: delivered energy measured with a defibrillator analyser, rhythm analysis with simulated signals, battery condition and pad expiry. Our AED maintenance checklist covers the monthly checks.
How often to calibrate
Follow the interval the manufacturer specifies in the service manual. Where none is given, annual is a common baseline. In addition to the routine schedule, check a device:
- After any repair or part replacement
- After it is dropped, knocked or exposed to liquid
- After a software update that affects measurement
- Whenever users suspect readings do not make sense
Heavily used equipment, such as devices in ambulances or the ICU, may need checking more often than the minimum interval.
What a good calibration record contains
A calibration report that will stand up in an audit should include:
- Asset ID, make, model and serial number
- Date of the check and the next due date
- The reference equipment used, with evidence that it is itself calibrated and traceable
- The actual measured values against the manufacturer's tolerance, not just the word "pass"
- Any adjustments made or parts replaced
- The pass/fail result and the name of the person who did the work
A label on the device showing the check date and next due date lets users see its status at a glance.
How Thunder Venture Group can help
Our in-house biomedical engineering team provides scheduled calibration and preventive maintenance, annual safety inspections and on-call repair. Calibration is traceable to manufacturer standards and documented at every visit, and our field engineers cover all 77 provinces.
See our services page for details, or read the ventilator buying guide for the maintenance costs worth weighing before you buy.
Frequently Asked Questions
What is the difference between calibration and maintenance?
Calibration compares what a device measures or delivers against reference equipment and adjusts it into tolerance. Preventive maintenance is inspecting, cleaning and replacing wear parts before they fail.
How often should medical equipment be calibrated?
At the interval the manufacturer specifies. Where none is given, annual is a common baseline, with extra checks after repair, after a drop, or whenever readings are in doubt.
What does "traceable" calibration mean?
It means the reference equipment used has itself been calibrated against higher-level standards in an unbroken, documented chain, so the results can be trusted.
What is IEC 62353?
It is the international standard for recurrent electrical safety testing and testing after repair of medical electrical equipment, covering checks such as leakage current and earth continuity.
Need a calibration and maintenance plan?
Our in-house biomedical engineers calibrate to manufacturer standards, with traceable results documented at every visit, across all 77 provinces.