A3.2.3.2 Mount the Zeitfuchs cross-arm viscometer in the
constant-temperature bath, keeping tube N vertical. Introduce
the test specimen through tube N, taking care not to wet the
sides of tube N, into the cross-arm D until the leading edge
stands within 0.5 mm of fill mark G on the siphon tube. The
volume of the test specimen is dependent on the location of the
fill mark G. When the flow time of the lower meniscus is being
measured between timing marks E and F (see A3.2.6), the
upper meniscus shall be in the horizontal cross-arm D, thus
making the location of fill mark G critical.