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04.14
product manual
H-4195
Soil Penetrometer, Pocket Style
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General
The Pocket Penetrometer is designed as a lightweight instrument for use by
field personnel to check visual classification of soils. It can be used to verify
whether excavation side walls require shoring, based on OSHA cohesive
soils classifications.
It indicates consistency, shear strength, and approximate unconfined shear
strength. Direct-reading scale—in tons/sq ft, or kg/sq cm—corresponds to
equivalent unconfined compressive strength. The readings obtained from
the Penetrometer do not replace laboratory test results due to the fact
that a small area of penetration test could give misleading results. The
instrument should not be used for obtaining foundation design data.
Instruction
The red ring on the barrel of the penetrometer is designed to maintain the
test reading on the scale for easy reading.
To operate, slide the ring down against the handle (knurled portion) of the
penetrometer. Grip the handle and push the tip of the penetrometer into
the soil so the groove marked on the tip is even with the level of the soil.
Once this is done, you can read the scale to determine the unconfined
compression strength directly from the scale in tons per square foot (TSF) or
kilograms per square centimeter (kg/cm2).
The reading should be taken from the lower side of the red ring, i.e. the side
closest to the knurled handle.
The scale is calibrated in tons per square foot or kilograms per square
centimeter unconfined compressive strength.
Maximum reading of the Penetrometer is 4.5 tons per square foot or 4.5
kilograms per square centimeter. Pocket Penetrometers are not individually
calibrated and therefore, no calibration certificates are supplied. An error of
up to 1/2 division on the scale, equivalent to 0 to 0.124 TSF, is possible with
the instrument.
Notes:
Select test spots with a smooth surface. Hold the pocket penetrometer at
right angles to the surface being tested. To minimize errors, take several
readings near each other, discard those readings that may vary significantly
from the majority and average the readings.
Adapter Foot
The H-4195F Adapter F oot is recommended when testing extremely low
strength cohesive soils. 1" (25mm) dia. foot, compared to the 1/4" (6.35mm)
penetrometer piston, increases the effective area measured by 16 times.
Divide by 16 to obtain correct unconfined compressive strength when the
reading in tons per square foot or kilograms per square centimeter is on the
low-load side.
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OSHA Soil Categories
OSHA categorizes soil and rock deposits into four types, A through D,
as follows:
Stable Rock: is natural solid mineral matter that can be excavated with
vertical sides and remain intact while exposed. It is usually identified by a rock
name such as granite or sandstone. Determining whether a deposit is of this
type may be difficult unless it is known whether cracks exist and whether or not
the cracks run into or away from the excavation.
Type A Soils: are cohesive soils with an unconfined compressive strength of 1.5
tons per square foot (tsf) (144 kPa) or greater. Examples of Type A cohesive soils
are often: clay, silty clay, sandy clay, clay loam and, in some cases, silty clay loam
and sandy clay loam. (No soil is Type A if it is fissured, is subject to vibration
of any type, has previously been disturbed, is part of a sloped, layered system
where the layers dip into the excavation on a slope of 4 horizontal to 1 vertical
(4H:1V) or greater, or has seeping water.
Type B Soils: are cohesive soils with an unconfined compressive strength greater
than 0.5 tsf (48 kPa) but less than 1.5 tsf (144 kPa). Examples of other Type B
soils are: angular gravel; silt; silt loam; previously disturbed soils unless otherwise classified as Type C; soils that meet the unconfined compressive strength or
cementation requirements of Type A soils but are fissured or subject to vibration;
dry unstable rock; and layered systems sloping into the trench at a slope less
than 4H:1V (only if the material would be classified as a Type B soil).
Type C Soils: are cohesive soils with an unconfined compressive strength of 0.5
tsf (48 kPa) or less. Other Type C soils include granular soils such as gravel, sand
and loamy sand, submerged soil, soil from which water is freely seeping, and
submerged rock that is not stable. Also included in this classification is material
in a sloped, layered system where the layers dip into the excavation or have a
slope of four horizontal to one vertical (4H:1V) or greater.
Layered Geological Strata: Where soils are configured in layers, i.e., where a
layered geologic structure exists, the soil must be classified on the basis of the
soil classification of the weakest soil layer. Each layer may be classified individually if a more stable layer lies below a less stable layer, i.e., where a Type C soil
rests on top of stable rock.
Penetrometer Adapter Foot
The H-4195F Adapter foot is recommended when
testing extremely low strength cohesive soils.
1" (25mm) dia. foot, compared to the .25" (6.35mm)
penetrometer piston, increases the effective area
measured by 16 times. Divide by 16 to obtain correct
unconfined compressive strength when the reading in
tons per square foot or kilograms per square centimeter is on the low-load side.
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www.humboldtmfg.com
HUMBOLDT
Testing Equipment for
Construction Materials
Humboldt Mfg. Co.
875 Tollgate Road
Elgin, Illinois 60123 U.S.A.
U.S.A. Toll Free: 1.800.544.7220
Voice: 1.708.456.6300
Fax: 1.708.456.0137
Email: hmc@humboldtmfg.com
Warranty
Humboldt Mfg. Co. warrants its products to be free from defects in material or
workmanship. The exclusive remedy for this warranty is Humboldt Mfg. Co.,
factory replacement of any part or parts of such product, for the warranty of this
product please refer to Humboldt Mfg. Co. catalog on Terms and Conditions
of Sale. The purchaser is responsible for the transportation charges. Humboldt
Mfg. Co. shall not be responsible under this warranty if the goods have been
improperly maintained, installed, operated or the goods have been altered or
modified so as to adversely affect the operation, use performance or durability
or so as to change their intended use. The Humboldt Mfg. Co. liability under
the warranty contained in this clause is limited to the repair or replacement of
defective goods and making good, defective workmanship.
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