Know your equipment and perform daily inspections of it – should only take a minute for each day you use it. At a minimum, you should meet the following:

1. A log of calibration results
2. Documentation of repairs or other alterations, which return the equipment to acceptable operation
3. A record of dates of computer software and hardware updates or changes
4. If the equipment is changed or relocated elsewhere, calibration checks and quality-control procedures must be repeated before you commence with further testing

These are the key features of quality control in spirometry:

The spirometer calibration must be verified on a daily basis using a 3 litre syringe following the manufacturer’s recommended procedure.

A volume calibration check should be performed at least daily with a single or multiply discharge of a 3-L calibrated syringe. Daily calibration checking is necessary so that the onset of a problem can be determined as soon as possible.

More frequent checks may be required – in special circumstances, such as:

• If an error in results is suspected during performing a test
• During particularly busy clinics where a large number of subject manoeuvres are carried out, the equipment’s calibration should be checked more frequently than once per day. It is recommended that you perform a volume calibration every ten subjects
• When the ambient temperature is changing (>4 or 5ºC), particularly in the summer, the volume accuracy must be checked more frequently than daily and the BTPS correction factor appropriately updated
• To perform a volume calibration in the morning and at lunch should accommodate these changes and it is good practice to do this throughout all seasons