Hi dwc,
We offer calibration services. If you are in the US, you can send the unit in and for a small fee, the unit will be calibrated. If you purchased through a distributor, you will need to contact a distributor and they will help you through the process. If in the US, call us at either 1800-260-TEST or email us at support at signalhound and we can give you a price and shipping instructions.
Regards,
A.J.