Table 6 to Subpart IIIII of Part 63 - Examples of Techniques for Equipment Problem Identification, Leak Detection and Mercury Vapor

Table 6 to Subpart IIIII of Part 63 - Examples of Techniques for Equipment Problem Identification, Leak Detection and Mercury Vapor

As stated in Tables 1 and 2 of Subpart IIIII, examples of techniques for equipment problem identification, leak detection and mercury vapor measurements can be found in the following table:

To detect . . .	You could use . . .	Principle of detection . . .
1. Leaking vent hoses; liquid mercury that is not covered by an aqueous liquid in open-top containers or end boxes; end box covers or stoppers, amalgam seal pot stoppers, or caustic basket covers not securely in place; cracks or spalling in cell room floors, pillars, or beams; caustic leaks; liquid mercury accumulations or spills; and equipment that is leaking liquid mercury	Visual inspections
2. Equipment that is leaking hydrogen and/or mercury vapor during inspections required by Table 2 to this subpart	a. Auditory and visual inspections
	b. Portable mercury vapor analyzer - ultraviolet light absorption detector	A sample of gas is drawn through a detection cell where ultraviolet light at 253.7 nanometers (nm) is directed perpendicularly through the sample toward a photodetector. Elemental mercury absorbs the incident light in proportion to its concentration in the air stream.
	c. Portable mercury vapor analyzer - gold film amalgamation detector	A sample of gas is drawn through a detection cell containing a gold film detector. Elemental mercury amalgamates with the gold film, changing the resistance of the detector in proportion to the mercury concentration in the air sample.
	d. Portable short-wave ultraviolet light, fluorescent background - visual indication	Ultraviolet light is directed toward a fluorescent background positioned behind a suspected source of mercury emissions. Elemental mercury vapor absorbs the ultraviolet light, projecting a dark shadow image on the fluorescent background.
	e. Portable combustible gas meter
3. Level of mercury vapor in the cell room and other areas	a. Portable mercury vapor analyzer - ultraviolet light absorption detector	See Item 2.b.
	b. Portable mercury vapor analyzer - gold film amalgamation detector	See Item 2.c.
	c. Permanganate impingement	A known volume of gas sample is absorbed in potassium permanganate solution. Elemental mercury in the solution is determined using a cold vapor adsorption analyzer, and the concentration of mercury in the gas sample is calculated.