SCS offers a line of combo testers designed to confirm proper function of both heel and wrist ESD grounding straps, such as 770031. These devices usually ship with their calibration certificates, but what happens if one does not, or if someone loses the cert?
Not to worry. SCS allows users to download the calibration certificates for these devices from their website; 770031 Combo Wrist Strap and Footwear Tester with Stand as an example for the stated product. You can also request recalibration services from SCS on the same product page, though this comes with a service charge. The products are calibrated to NIST standards at the factory and these records are kept by SCS.