The accuracy of the syringe volume must be considered in determining whether the measured volume is within acceptable limits.
The syringe used to perform a calibration check of the spirometer must have an accuracy of +/-15ml or +/-0.5% for a 3L syringe. This is checked by the manufacturer.
The syringe should be factory calibrated on an annual basis. The manufacturer must provide details of this process. In addition to the annual syringe calibration, you should perform a monthly leak check.
This can also be performed when you suspect there may be a leak with it.
In the event of you detecting a leak, the syringe must be returned to the manufacturer for repair and re-calibration.
The procedure is to cork or block the outlet of the syringe and attempt to inject it. Where the syringe has been damaged a fine leak would allow the syringe to be injected. Of course a degree of force is required to overcome the resistance of small leaks.
In the event of you detecting a leak, the syringe must be returned to the manufacturer for repair and re-calibration.