Approved-Class Scales: What Singapore Clinics Need to Know

Weighing instruments are regulated differently depending on what the weight is used for. A scale used to inform a clinical decision sits in a different category from one used for general interest.

Why the class matters

Approval classes specify the permitted error across the weighing range. A domestic scale has no such guarantee, and — importantly — no requirement to hold its accuracy over time. Two scales can display the same resolution while only one is verified to be accurate to it.

Resolution is not accuracy. A scale showing 0.1 kg increments is telling you how finely it displays, not how correct the number is.

What to check before buying

• Stated approval class appropriate to clinical use.
• Verification marking on the instrument.
• Calibration service availability locally — an instrument that has to go overseas for recalibration is out of service for weeks.
• Documentation you can put in a quality file.

Regulatory context in Singapore

Weighing instruments used in trade and in certain regulated applications fall under weights and measures requirements administered by Enterprise Singapore. Medical devices are separately regulated by the HSA. Which applies depends on the instrument and its use, and the practical answer for a clinic is to buy an instrument the supplier can document as suitable for clinical measurement, and to keep the paperwork.

See HSA registration: what buyers need to check.

Keep a calibration record

Log every check and recalibration: date, result, who performed it. If a weight is ever questioned — a dosing incident, an audit — the record is what separates a defensible measurement from an assumption.

Clinical scales are in medical scales. See also calibration schedules and the scales buying guide.

General guidance. Confirm current requirements with the relevant authority for your specific application.