This SOP can be used to set procedures for general calibration. 

The calibration log can be used to record calibration of a particular piece of equipment. It is critical that calibration records include (or allow reference to other documentation which includes) the following (see 21 CFR §111.35): The equipment calibrated; the date of calibration; the reference standards used for calibration; the accuracy and calibration history of the standards; the calibration method used; the allowed limits for accuracy and precision; the readings found; any recalibration methods and readings; the initials of the person performing the calibration and/or recalibration. In the event that a piece of equipment fails calibration, there may need to be an investigation as per 21 CFR §111.113(a)(4). Any recalibration or repair of the affected equipment may be documented as a Corrective and Preventive Action (CAPA). Reference to the investigation report number and/or CAPA report number can be made in the right-hand column of the log.]