(a) You must install and maintain all meters that we require, either according to the manufacturer's recommendations and specifications or paragraphs (b) through (e) of this section, whichever are more restrictive.

(b) If you use an orifice plate to calculate Federal royalty, the orifice plate installation must comply with “API Manual of Petroleum Measurement Standards, Chapter 14, Section 3, Part 2, Fourth Edition, April 2000.”

(c) For meters used to calculate Federal royalty, you must calibrate the meter against a known standard as follows:

(1) You must annually calibrate meters measuring electricity;

(2) You must calibrate meters measuring steam or hot water flow with a turbine, vortex, ultrasonics, or other linear devices, every 6 months, or as recommended by the manufacturer, whichever is more frequent; and

(3) You must calibrate meters measuring steam or hot water flow with an orifice plate, venturi, pitot tube, or other differential device, every month, and you must inspect and repair the primary device (orifice plate, venturi, pitot tube) annually.

(d) You must use calibration equipment that is more accurate than the equipment you are calibrating.

(e) BLM may modify any of these requirements as necessary to protect the resources of the United States.