Have you been contacted by Trading Standards about auditing your scales? There are plenty of non-compliant scales in GP Surgeries.
The Non-Automatic Weighing Instruments Regulations divide scales into four classes - class I is the very highest accuracy and class IV is the lowest. The UK Weighing Federation has published guidance for healthcare organisations regarding what class of scale can be used for what type of healthcare task.
In summary, if you are simply monitoring a patient's weight for their medical records, the lowest accuracy class IV scale is sufficient. These are the standard mechanical scales that go up in 1kg increments and that you see in most general practices.
If you are using the weight of the patient to diagnose a condition or to prescribe the correct dosage of a drug, class III scales are recommended. These are the digital scales which tend to go up in increments of 100g or 200g.
Information on: National Medical Weighing Equipment Project 2014/15