S.C. Code Ann. § 40-53-40: Minimum requirements for instruments.

Any instrument used to test or question individuals for the purpose of detecting deception or verifying truth of statements shall record visually, permanently and simultaneously: (1) the subject's cardiovascular pattern and (2) respiratory pattern. Patterns of other physiological changes in addition to (1) and (2) may also be recorded. The use of any instrument or device to detect deception or to verify truth of statements which does not meet these minimum instrumentation requirements is hereby prohibited and the operation or use of such equipment shall be subject to penalties and may be enjoined in the manner hereinafter provided.