---
kind: "section"
citation: "30 C.F.R. § 33.21"
title: "30"
number: "33.21"
heading: "Modification of test equipment."
url: "https://uscodex.org/cfr/30/33.21"
---

# §33.21. Modification of test equipment.


For test purposes the unit or system may be modified, such as by attaching instruments or measuring devices, at MSHA's discretion; but such modification shall not alter its performance.


## Notes

### Authority

Authority: 30 U.S.C. 957, 961.

### Source

Source: Schedule 25B, 25 FR 6473, July 9, 1960, unless otherwise noted.