| It is common practice for manufacturers of gas detection or analysis instruments to despatch new instruments to their customers accompanied by a Calibration Certificate. Such a certificate will include details of the actual gas used to calibrate the instrument, as well as the date of calibration. This will give the customer reassurance that the instrument is ready for use. It is normal practice for analytical equipment to be accompanied by a certificate showing that the calibration was traceable to national standards. Some instruments require regular recalibration, at intervals recommended by the manufacturer. It should be noted that the original Calibration Certificate for such an instrument is not valid for the lifetime of the instrument. The manufacturer’s recommendations for recalibration will be listed in the Operating Instruction Manual of the instrument, together with the calibration procedure to be followed. If the recalibration is carried out by the manufacturer, a fresh Calibration Certificate will normally be issued. If the instrument is recalibrated by the user, the manufacturer’s original Calibration Certificate becomes invalid. This would also be the case if the instrument has had a sensor replacement during its lifetime, as such an operation will necessitate a recalibration. |