Field inspection manual—volumetric measuring devices–Part 4, section 32

Part 4, section 32—Specialised test procedures—sensitivity test (calibrated tanks)

Application

This procedure is used when performing accuracy tests on any fixed, mobile or vehicle mounted tanks.

Purpose

Sensitivity in static volumetric measurement refers to the ability of a measuring tank to show a difference in liquid level equivalent to or less than the limit of error. The addition or subtraction of a given volume must raise or lower the level by a minimum prescribed distance.

Legislative references

R.302, R.314, R-325.

Procedure

Fill to the calibrated mark; if there are several markers in the tank or compartment, fill to the lowest one.

Add a quantity of product equal to the limit of error.

After any wave action stops, carefully place a 2 mm or 5/64 inch thick piece of metal on top of the flat surface of the level indicator; if product covers the upper surface of this piece, an indicator is allowed at this capacity.

Note: The reduced thickness of the piece is to compensate for the capillary effect of the liquid. The piece should be attached to a wire or string in case it is dropped into the tank.

Interpretation of results

Capacity indicators shall not be installed at any level where the quantity of liquid equal to the limit of error does not cause the level of liquid to raise by at least 2.5 mm or 3/32 of an inch (R.302).

Revision

Original document