CFR › Title 21 › Part 870 › §870.237021 CFR §870.2370Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Identification. An electrocardiograph surface electrode tester is a device used to test the function and application of electrocardiograph electrodes.(b)Classification. Class II (performance standards).