Troxler EGauge 4590 - Page 96

7–2
A
A
b
b
o
o
u
u
t
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O
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f
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s
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e
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The Troxler Model 4590 is factory-calibrated for typical soil
materials. Gauge readings can be adjusted based on
alternative density tests, such as sand cone or drive cylinder
tests. This adjustment, or shift, is known as an offset.
NOTE
When an offset has been enabled, all future readings will
automatically be adjusted until the offset is disabled or the
gauge is turned off. Be sure to disable offsets and prior to
taking readings on materials that do not require an offset.
Offsets will be disabled if the gauge is turned off for more
than 10 seconds.
The gauge provides density, trench and moisture probe offset
options.
The density offset is often needed if the material has a density
that is outside the range of 70 to 170 pcf (1100 to 2700 kg/m
3
).
Also, if material has a high concentration of elements with
atomic numbers greater than 20 (such as concrete, some coals,
or ferrous soils).
A trench offset should be used if measurements are to be taken
inside a trench or close to a solid structure such as a wall,
barrier, or construction equipment. The Trench offset is not
needed if all density measurements are to be performed at 6”
(150 mm) or deeper in the trench situation.
A moisture probe offset is often needed to achieve accurate
moisture results in the field on regional soils. The factory Cal
Profiles are not representative of all soil types. This offset
should be used when the moisture content of a laboratory
sample differs from the reading provided by the Troxler
Moisture Probe Model 6760 (included).
The moisture offset function is a simple procedure to adjust the
moisture readings up or down. A new Cal Profile (p. 5-2) can
also be created for regional soils if needed. This is generally
used on soils with large moisture ranges. Otherwise a moisture
offset to one of the factory profiles works well.