Brandy,
Annual calibration and performance verification seems to be a logical and adequate cycle time for temperature control equipment.
Monitoring of temperature accuracy, i.e. daily checks or continuous monitoring, are also needed. The lab needs to define acceptable limits for temperature plus show the equipment performed to stated specifications over time. Since your commissioning process is rigorous in terms of temperature mapping, I would bet you have defined ranges already. What is your process for this, and do you use thermometers whose calibration is traceable to standardized reference materials (NIST or other internationally recognized standard)? Devices should clearly be marked with the date of most recent calibration, who performed this, plus the expiration date. You'll need a defined process by which you are reminded of due dates , the way you're required to respond if you find a unit is out of specification, who is responsible for the checks and are these checks verified by a second person.
Also who owns the processes and is responsible for maintaining the SOP, calibration certificates, equipment records?
Does your process define a frequency and procedure for equipment maintenance, like defrosting the freezer?
Lastly, which specifications do you use for these processes? Define requirements for the third party supplier of the calibration certificate, and define the required standards, specifications, and acceptance criteria for the calibrations. For example , does the supplier need ISO 17025 accreditation? Do they have accreditation to the temperature and humidity humidity cals?
Service provider should be willing to submit their written SOP prior to doing the work, because you will be better off knowing that their process meets your requirements.
Mara Jensen
QC Equipment Specialist